Signal and Information Processing, Networking and Computers

The integration test of spacecraft attitude and orbit control system (AOCS) is an important means to confirm whether the design of the system meets the mission requirements throughout the whole process of system development. The AOCS based on 1553B bus architecture is gradually applied to Chinese spacecraft. In this paper, the status of AOCS integration test and the characteristics of the AOCS based on 1553B bus architecture are analyzed and a satellite-ground integration test scheme for AOCS based on 1553B bus architecture is proposed. The scheme of testability and ground environment for four types of integration test are introduced and the technical features of sensor closed-loop method, actuator closed-loop method and component RT simulation method are emphasized. The application of the test scheme for AOCS of the satellite is also given. The test scheme has the advantages of universality, expansibility, convenience and reliability, which can improve the test efficiency and quality of AOCS significantly.

Radio frequency crosslink is usually used in constellation which is composed by several satellites. Deviation of the antenna pointing angle can lead to failure in the setting process of crosslink. Satellites will involve more deviation of antenna pointing angles in real orbit condition. So it is important to test the engineering design accuracy of satellite antenna pointing algorithm. A test system of satellite antenna pointing performance based on dynamic orbit model is designed, which is used to solve the problem of timing deviation of data in the test process of satellite antenna pointing performance. The timing deviation model is analyzed. Using the timing recovery module, the test error results (with and without timing information) of antenna pointing angle are unified, both of which are within 0.001° when the test process is based on the same orbit condition. Thus, the test system proposed can get the reliable results of engineering design accuracy of satellite antenna pointing algorithm.

This paper provides a high accuracy orbit control design for ocean dynamics operational environmental satellite based on the orbital characteristics and the energy safety constraints of the satellite, which could meet the demand for high accuracy of orbit control.

Clock plays a vital role in navigation satellites, and its design method has a high barrier to entry. The in-orbit anomalies of clocks of global navigation satellite system (GNSS) such as Galileo and Indian Regional Navigation Satellite System (IRNSS) indicate that the stable operation of clocks has the characteristic of high-risk. Thus, it’s of great importance to monitor the frequency stability of that. Currently, monitoring technique based on the in-orbit data of phase comparison between a master and a backup clock (IDPCMB) is able to solve traditional disadvantages of complexity, expensiveness, and unstable measurement accuracy; however, it obtains a poor accuracy when faced with condition of short-term stability. The primary purpose of this study is to design a modified IDPCMB monitoring technique, which is based on an analysis of Allan Variance from a different perspective, and can solve the drawbacks of traditional technique. The testing results show that the modified technique is superior to the traditional one.

This paper introduces the design and implementation of multi-channel system level test scheme for high orbit high power SAR. Firstly, the working principle of high orbit SAR load is introduced, and then the composition and design scheme of SAR load comprehensive test equipment which is composed of echo simulator and SAR fast view are introduced. The test scheme design of satellite ground test link, test items and test methods for the characteristics of high orbit high power SAR satellite are carried out. The load system level test scheme and method of high orbit SAR have been applied in the test task. This paper introduces the application in practice.

Service modes of single access and multiple access for data relay satellite system (DRSS) are presented in this paper. According to independent link resource scheduling for two types of access, rapid response service mode with single access link and multiple access link satellite co-processing is proposed, which using data relay satellite (DRS) multiple access return links panoramic beams as application channel. Users’ access applications could be processed with digital beamforming at the ground center station (GCS) without changing the status of DRS and GCS. Access application can be rapidly responded by scheduling available single access and multiple access link resources with single or several satellites from GCS after request accepted. Users in orbit could achieve real-time or quasi-real-time access by applying online with both random access and rapid access. Rapid response service extends the normal service mode of data relay satellite system. Simulation results show the capability improved by optimization of system resource allocation. And these improve the efficiency and flexibility of service capabilities of DRSS.

Aiming at the problem that the high-precision satellite formation control strategy is complex and not easy to implement, a bionic intelligent formation management strategy based on bat flight is proposed. Firstly, it summarizes the behavior rules of bat groups in nature, gives the mathematical model of bat flight, and then gives the bionic formation management strategy. The algorithm is clear and practical. Finally, the satellite formation algorithm is used to simulate and verify the configuration of the satellite formation to achieve stable control with high precision and low energy consumption.

For the features of agile satellites that have more missions per track, and higher requirements for response speed and accuracy of execution, a meta-task-based autonomous operation scheme of Data Transmission Subsystem with traversal execution is proposed. All commands that need to be executed for autonomous operation of DTS are classified and sorted to form a “command pool”. The on-orbit missions, which are summarized into five basic meta-tasks, are executed by travelling all commands in the pool to improve the execution efficiency and use flexibility. With the adoption of onboard highly-precise time system, the key commands can be executed opportunely. The test result of a simulation system shows that, with the scheme proposed, the DTS can complete preparation or mode transition within a minute, the time accuracy of key commands’ execution is not greater than 20 ms, and the efficiency of mission data-blocks is doubled compared with the traditional operation mode. The proposed low-complexity scheme has great potential in the subsystem-level autonomy design of agile satellites.

Remote sensing agile satellites have many load working modes and large changes in attitude during the period of on-orbit. In this case, the lighting conditions and load power conditions are often in a complex dynamic process. Traditional data tabular statistical methods bring great limitations to accurate analysis of satellite energy balance. This paper proposes a dynamic energy balance simulation system based on MATLAB function programming by dynamic parameter models, combined with a series of characteristics of remote sensing agile satellites, such as diverse mission modes and rapid maneuvers, etc. using functional modules for programming and simulation based analysis in specific scenarios. It could reflect the dynamic changes of energy balance accurately and clearly, the method is easy to program, friendly to interact and can dynamically reflect the energy utilization trend of the system, providing important reference for remote sensing agile satellite energy system.

The marine oil spill pollution caused by offshore oil fields and oil tankers etc. has a great impact on the marine environment with the increase of human activities in the ocean. In order to detect and control the impact of the oil spill, people have done a lot of research on the ground and achieved many results, but the real-time performance of the ground processing and the coverage is insufficient. It is possible to use satellite observation data to carry out oil spill analysis with the development of satellite remote sensing technology. However, conventional oil spill observation methods are not suitable for oil species identification. From the perspective of oil spill analysis, the identification of satellite oil spill by means of spectral remote sensing, laser fluorescence and microwave detection is analyzed in this paper and the overall design of satellite for oil species identification is given.

To solve the problem that the traditional satellite test mode is low-efficiency, has a complicated process and cannot satisfy the batch test requirements of the global networking of micro-satellites, this paper studies the test process of micro-satellites. This paper summarizes the past type test experiences, sorts testing requirements and work of satellites, and proposes the implementation mode of the batch test process for satellites. With practice exploration on batch test process of six satellites of a type, the test tasks of the constellation are successfully completed. After the constellation is launched, it performs well in orbit. Achieved batch testing of micro-satellites and verified the feasibility and correctness of the batch testing process. Compared to traditional single-satellite test mode, the comprehensive work efficiency on the AIT (Assemble, Integrate and Test) stage under the batch test mode is improved by 30%. The batch testing process is undoubtedly more in line with the low-cost and high-efficiency characteristics of micro-satellites.

With the development of terrestrial 5G communication service, the C-band frequency which is exactly the frequency resources used by satellite broadcast and television will be used for the 5G low frequency ranges. In this paper, the interference caused by using the same C-band frequency resources between the satellite system and the terrestrial 5G business is analyzed. In order to solve this problem, a novel method is proposed to share the C-band which consists of frequency reverse use, frequency dual reuse, beam and polarization multiplexing. This innovative strategy can promote the integration and development of satellite broadcast business and terrestrial 5G communication, and improve the efficiency of frequency utilization simultaneously. Taking the advantage of satellite system, enhanced Mobile Broadband (eMBB) and massive Machine Type Communications (mMTC) use cases of 5G communication are suitable for the integrated satellite-terrestrial 5G system. The method described in this paper is a frequency use suggestion for satellite-terrestrial 5G, and the approval of radio management department is required for practical application.

An on-orbit lunar observation method is put forward in this paper aiming at the low earth orbit remote sensing satellite, including observation opportunity, satellite attitude planning and imaging parameters of load, etc. Based on a low-orbit optical remote sensing satellite, the lunar observation experiments were successfully carried out for 8 times in July 2019, and the lunar phase angle covered −79.872–81.657º.The experimental results suggest that the actual performance of satellite attitude is consistent with the designed satellite attitude planning process. Moreover, the method has a high observation efficiency with 1500 s duration. The texture of 8 lunar images obtained have a good sense of layering with clear and stable texture. Furthermore, the spatial resolution is up to 1.18 km. The results verify the correctness and rationality of lunar observation method proposed. It can provide a reliable basis for long-term monitoring of the imaging stability of the remote sensing satellites.

This paper designs and implements an IP that supports the CAN 2.0 protocol and integrates it into the designed SoC. The upper layer software can be used to control and manage the CAN protocol. The SoC that we designed in this paper adopts AHB and APB bus architecture, which can easily integrate the IP of this bus. The processor core uses a five-stage pipeline to support the ArmV4 instruction set architecture. The multiplication unit uses pipeline processing. The forwarding unit and scoreboard unit module can solve and alleviate data dependence and improve instruction execution efficiency. The design has been verified by simulation and its function is correct. The comprehensive results of the target device Spartan-7 show that the design consumes less resources and can be implemented in FPGA. The design can be used in satellite-based integrated electronic solutions of small satellite to complete data transmission and information exchange between spacecraft electronic equipment.

Remote Sensing satellite is an important means to acquire image information of key regions in order to meet the emergency needs of natural disasters like earthquake and wildfire. Limited by the orbit properties, the response time of the remote sensing satellite to the emergency mission is uncertain, and the revisit interval is long, which does not meet the rapid-response and frequent-visit requirement. In this paper, an orbit maneuver method is proposed, by adjusting the semi-major axis of the remote sensing satellite and changing the sub-satellite points, the satellite can respond to the emergency mission within 24 h and shorten the interval of the revisit to one day. Simulation results show that the proposed method is simple and effective, and can meet the requirements of emergency missions. Fuel consumed of a typical satellite for a specific mission is about 50 kg.

According to high resolution SAR/GMTI satellite subsystem antenna subsystem SAR antenna secondary power supply (hereinafter referred to as secondary power supply) multi-channel output, low output voltage, large current pulse load and a series of characteristics, this automatic test system through VEE software to the secondary power program in-depth development and improvement, and through the GPIB line control hardware equipment instrument, the realization of secondary power multi-channel simultaneous monitoring output waveform, multi-frequency special, command automatic switch machine, etc. test efficiency and reliability. Through the analysis and optimization of the test items of the secondary power supply, the automatic test system has designed a general programmable program, and can be applied to a variety of secondary power modules and single machine, the compatibility is very strong. At present, this automatic test system has been applied to the test of multiple types of SAR antenna secondary power supply, the test quality is 100% correct, the efficiency is greatly improved, and the results are remarkable.

Navigation satellite is a service satellite that provides users with real-time position. It needs to accurately predict the position of the navigation satellite, so the thruster cannot be used during the normal operation of the navigation satellite. In other fields, the thruster is usually used to unload the angular momentum, but the thruster will change the satellite position, so this method is not suitable for navigation satellite. According to the characteristics of angular momentum management of geo navigation satellite, this paper describes the design ideas and implementation methods from the aspects of flywheel configuration design, angular momentum management, magnetic torque converter unloading design and system implementation. A pyramid wheel configuration suitable for navigation satellite is designed, with one magnetic torque converter on the x-axis and one on the z-axis. At the same time, unloading logic and fault suitable for this configuration are designed Diagnosis and treatment. Finally, the data of one year in orbit operation are collected for targeted analysis, which proves that the design proposed in this paper is reasonable and effective, and has the value of popularization and use in other geo orbit satellites.

Global short message communication(GSMC) service provided by BeiDou Navigation Satellite System (BeiDou system, BDS) can be utilized by low earth orbit(LEO) earth observation satellites to achieve telemetry, tracking and control(TT&C) and information distribution throughout the day. The system architecture of TT&C applications for LEO satellites based on BDS GSMC service is proposed and service flow is given in this paper. A simulation scenario was established, and several service capabilities index including cover-age characteristics, data transmission path, data transmission delay, and reliability are simulated and analyzed. Results have shown that the GSMC service provides more than 75% of orbit coverage for LEO satellite users whose orbit attitude varies from 500 – 2000 km, while some users can achieve 100% cover-age. The maximum coverage block time interval does not exceed 25 min, and the data transmission delay of single frame is less than 108 s, with certain redundant transmission capability achieved. The service can effectively support the telemetry and telecommand and data distribution applications of LEO satellites abroad and can be used as a supplementary method in satellite TT&C systems.

Satellite power system provides satellite energy to ensure normal operation. This paper presents a hybrid optimal kernel extreme learning machine with a proportional coefficient method optimized by differential evolution algorithm (DE-PCM-OKELM) to predict the interval of the satellite power system parameter. First, the kernel extreme learning machine (KELM) with radial basis function is optimized by differential evolution algorithm to solve regression problems. Next, the proportional coefficient method (PCM) optimized by DE is utilized to construct predictive interval, where DE algorithm is used to get the best coefficient of PCM. In this paper, the integration strategy is used to improve the stability, prediction accuracy and generalization ability of the parameter interval prediction model. Moreover, the predictive interval obtained by the DE-PCM-OKELM model is non-symmetric rather than center symmetric with the predicted value. The experimental results demonstrate that DE-PCM-OKELM model can obtain higher predictive accuracy, shorter training time and testing time, narrower interval width and lower PIAI than other models. Furthermore, the proposed DE-PCM-OKELM model describes explicitly the variation range of the satellite power system parameters, PIAI is a comprehensive indicator combining PICP, PIMWP and MWD. Which is conducive for satellite to adopt defense measures in time.

A new method based on dynamic adjustment of action sequences is proposed in this paper, to solve the problem of low observation rate of traditional autonomous mission management. A payload topological model is constructed according to the purpose of the command and the characteristics of the equipment/module. Then, the mission instructions of the equipment on the satellite are dynamically adjusted according to the real-time working state and the attributes of the action sequence, so that the dynamic programming of equipment switching between missions is realized, which can improve the completion rate of intensive observation missions on the basis of satisfying the constraints on the satellites. The on-orbit application results of a high-resolution remote sensing satellite show that compared with the traditional autonomous mission management method, the number of missions completed and the observation time are effectively increased, and the satellite utilization efficiency is elevated for more than 40%.

Simulation technology has been widely used in the aerospace field due to its economical and rapid nature. The simulation technology based on STKX not only inherits the professionalism and fidelity of STK (Satellite Tool Kit), but also can be seamlessly integrated into the software, which has become a key technology in the simulation research in the aerospace field. The agile satellite is a kind of satellite that can observe the ground target quickly and flexibly. It is of great significance to guarantee modern agriculture, disaster prevention and reduction, resource investigation, environmental protection and national security in China. This article takes the agile satellite ground observation imaging as the engineering background, expounds the basic principles of STKX technology, explains the engineering and technical issues such as the creation of satellites, cameras and observation targets in scene simulation, and uses Cesium to demonstrate simulation effect of ground observation imaging. It aims to provide reference for the engineering application of STKX technology.

The magnetometer designed in this paper is an integral part of the satellite plasma and surface charge risk monitor. Its main function is to predict the discharge current by monitoring the change of magnetic field and compare the magnetic field changes with the possible satellite anomalies. This can be used to study the correlation between the orbital plasma environment and the satellite’s typical charge and discharge events. The system design of the magnetometer and the analysis results of the magnetic field data during the vacuum thermal test of the satellite are introduced in the paper. Analysis results show that the state change of omnidirectional electron detector will cause the change of magnetic field measurement.

Space-borne global navigation satellite system (GNSS) radio occultation (RO) is a superior tool for global sounding of atmosphere and ionosphere. The amount of operated low Earth orbit (LEO) satellite equipped with GNSS RO receivers for atmospheric sounding are surging in recent years. The orbits of these RO sounding satellites are varied because of the requirement of multitask. A digital simulation system aimed at GNSS RO atmospheric sounding satellite constellation design with or without on-orbit LEO satellites is presented in this paper. The system contains two main simulation modules. One of them is a transient position and velocity generator for both LEO satellites and GNSS satellites. The other is a forward GNSS RO event simulator for GNSS-LEO atmospheric sounding. In addition, a data processing module and graphical user interface (GUI) are designed and developed for interacting the data convenient and efficient in the initiative design of LEO satellite constellation. A Walker-δ satellite constellation with 6 LEO satellites is designed based on this system with simulations of GPS RO atmospheric sounding.

A certain type of microwave remote sensing satellite has wide frequency coverage, coexistence of high-power transmission and high-sensitivity reception, most of the stand-alone equipment on the satellite exceed the requirements in the satellite load receiving frequency band, and the electromagnetic environment is extremely complex. Satellite payload equipment is mostly related to radio channels. Preventing other systems from interfering with itself (conductivity and radiation sensitivity tests) and not interfering with other systems (conduction and emitted emission tests) are top priorities for EMC work. Through system-level EMC tests on satellites, after finding and confirming the interference source, the correct processing method is adopted to take different suppression measures for satellite EMC interference source, sensitive equipment, relevant cables and holes and seams, so as to ensure the whole satellite to pass the EMC test verification successfully. This paper focuses on the EMC problem in the development of satellite, proposes and implements a comprehensive treatment of the satellite system-level shielding, which combines various measures to reduce the impact of electromagnetic interference on equipment performance. This method effectively solves the problem of electromagnetic interference and ensures the safety of the satellite from the perspective of electromagnetic compatibility.

The reuse strategy for current satellite control software, which gives the percentage of reuse property less than 30%, is based on software snippets. With the rapid growth of satellite R&D missions, the development method for satellite control software is changing to the way that consists of standard-hardware assembly and software-defined function. The role of on-board software becomes more important, and requirements on software become stricter as well as the decreasing development period. The software development ability is currently constraining the satellite development. Based on the problem aforementioned, it is the tendency to strengthen the software productization and improve the software reuse rate. This paper introduces the reuse method based on software product line technology for control software of low-Earth orbit (LEO) satellite, and analyzes the key techniques including satellite domain analysis, software architecture modeling, component design and variability management. The application for new satellite constellation is demonstrated and verified that more than 80% of the reusable core asserts can be realized, while comprehensive and systematic software reuse can be achieved for specific domain.

With the sharp improvement of the satellite’s ground-to-ground resolution and the development of the whole satellite’s autonomous mission, the contradiction between the observation data downloading and attitude maneuver imaging during satellite transit has become increasingly prominent. This paper proposes a data transfer to the ground during attitude maneuver The antenna motion compensation technology can ensure that the normal data transmission of the ground-based digital transmission antenna can be continued during the satellite attitude mobile imaging, thereby improving the efficiency of satellite data use.

Aiming to improve the robustness of GEPSVM to outliers, in this paper, we propose a generalized nonparallel proximal support vector machine based on arbitrary Lp-norm and Ls-norm (GNPSVM), where $$ p,s > 0 $$ p , s > 0 . An effective and simple iterative technique is introduced to solve GNPSVM. The convergence of the above algorithm is also given. Experimental results support the superiority of GNPSVM.

Bit error rate (BER) may get worse, when the received spectrum of signal fluctuates in satellite data transmission system. It has set up three typical amplitude-frequency (AF) fluctuation models which are linear, zigzag and sinusoidal type. The whole link simulation model is established and the effect of the fluctuations is researched. It’s demonstrated that the affection of the fluctuation could be decreased by improving the input signal to noise (SNR), if the AF characteristic is linear which represents a simple case. However, The BER performance of sinusoidal type deteriorates rapidly and improved hardly with the increase of SNR. In order to stabilize the satellite data transmission link and acquire expected BER performance, the AF fluctuation should be restricted strictly. It is suggested that if the fluctuation is less than 3 dB, better BER performance could be achieved by a small increase of input SNR. It’s instructional for the system design and verification of satellite high rate data transmission.

Satellites with chemical propulsion systems have a basic 1:1 relationship between propellant weight and satellite dry weight, while satellites with full-electric propulsion have a significant reduction in satellite weight but a long orbital transition, while satellites with hybrid propulsion systems combined with chemical and electrical propulsion can balance between the two. After the satellite separates from the carrier rocket. it first carries on the chemical propulsion to change the orbit, then throws off the chemical propulsion, reduces the weight, then carries on the full electric propulsion to change the orbit. The whole transfer orbit has a long duration and complex working condition, which requires satellite to complete independently. In this paper, a closed-loop test and verification method for autonomous flight is designed to establish the operating environment of the satellite during autonomous flight State, simulate all kinds of excitation signals needed during autonomous flight of satellite, at the same time, simulate the load characteristics of various driving signals by satellite, and realize the full closed loop test of autonomous flight.

In this paper, the influence of carrier phase noise on the performance of modulation and demodulation in satellite communication downlink is simulated and analyzed. The influence trend of carrier phase noise on demodulation of different sampling rates and symbol rates under specified modulation mode is elaborated. We have come to the conclusion that: the influence of carrier phase noise on performance of specified modulation mode is related to sampling rate and symbol rate, and is also closely related to parameter setting of receiving system. Therefore, if we want to restrict the influence of carrier phase noise of transmitter on final demodulation performance, we need to consider different code rates have different influence of the phase noise on the performance under specified modulation mode. Meanwhile, we need to consider the whole transmission link, not only the transmitter itself, but also the relevant design parameters (loop form, bandwidth setting and damping coefficient setting) of the receiving system should be carefully designed and constrained to minimize the influence of carrier phase noise on modulation and demodulation performance.

As a new type of satellite communication, satellite data link has attracted more and more attention from various countries. This article aims to discuss the channel coding simulation method of satellite communication data link based on big data, in order to provide a solution for further improving the reliability of tactical data link. This paper presents a satellite data link system solution based on LDPC encoding. After simulation, it is found that under the AWGN channel, the error performance of the LDPC (1008,504) data link when the Eb/N0 is greater than −0.6 dB is better than that of the JTIDS type system. When the bit error rate is 10–5, the LDPC data link system has an advantage of about 5 dB. As an alternative code group for channel coding technology, LDPC codes can improve the transmission reliability of the data link, and have certain application prospects in tactical data links.

Navigation signals are the carriers for providing navigation services. The signal quality level determines the accuracy of navigation positioning. With the increase in the complexity of navigation signals and the aging of device components, the navigation signals generated by satellites will produce certain distortions. For the level of accuracy, predistortion optimization of signal quality needs to be carried out on-orbit and injected into the navigation satellite through parameter reconstruction to ensure the accuracy and stable operation of the quality of the navigation signal. This paper introduces a reconstruction design method of spaceborne predistortion parameters, designs a hardware architecture of CPU + FPGA, and optimizes the design of the bus, injection path, and injection information format to realize the in-orbit injection and predistortion parameters. Enabling to solve the problem of on-orbit signal quality distortion. This solution is applied to the Beidou-3 satellite payload, which ensures that the quality pre-distortion parameters can be adjusted and optimized on-orbit, and also lays a solid foundation for subsequent signal quality improvement.

On the condition of spatial imaging, remote-sensing images are always blurred by many elements. Wiener filter method is broadly used in semi-blind image restoration field. To avoid complex operations of power spectrum ratio in traditional Wiener filter, a new semi-blind remote sensing image recovery method on the basis of improved Wiener filter and comprehensive evaluation factor was presented. The method adopts improved Wiener filter to restore the blurred remote sensing data. And the degraded function factor is appraised via linear motion model. The power spectrum specific value of acquired remote sensing image is evaluated through multiple iterative calculation. Iterative stopping condition is stipulated by an integrated evaluation parameter, which is comprised of three no-reference quality parameters, GMG, IE and CF. Simulations and experiments indicate that the improved Wiener filter method acquires relatively approving restoration results and time overhead. And the proposed algorithm could be applied in restoring the remote sensing images blurred by linear motions and Gaussian noise.

Aiming at the problems of current power transmission and transformation equipment inspection, such as insufficient means and heavy tasks, a design for the core index of remote sensing satellite for inspection is proposed. First, this paper analyzes the inspection demand, and constructs a multi-means coordinated inspection mode. Then, the network design of 4 satellites is proposed, while three imaging modes are introduced, including the multi-target imaging mode, the stereo imaging mode and the splicing imaging mode. A comprehensive detection scheme (spatial resolution of panchromatic: 0.5 m, multi-spectral: 2 m, low-light: 2 m, mid-wave infrared: 5 m and long-wave infrared:10 m) is put forward, where the imaging width is more than 12 km, and the satellite’s attitude maneuvering ability is more than ±40°. Finally, STK (Satellite Tool Kit) is used to carry out simulation analysis on the proposed indicators. The results show that the constellation designed in this paper can revisit any global target within 24 h. It can provide reference for the construction of special remote sensing satellite system for power transmission and transformation equipment inspection.

With the rapid growth of the space - borne imaging system complexity, the comparison and iteration of multiple schemes need to be solved. The space-borne camera radiance transfer model, the requirement model, the system architecture model, the calculation and analysis model and the generalization relationship is built by MagicGrid Methodology. The comparative analysis results show that the different solutions results are presented more intuitively and the iteration speed is faster significantly. The solution No. 2, No. 4 and No. 5 can meet the requirement of the SNR (>50 dB) in the condition of the same imaging electric circuit (the correlated double sampling), the same orbit measurement system (500 km altitude obit) and the same land position (45°northern latitude). The SNR using off-axis three mirrors optical system is higher than the one using coaxial three mirror system or transmission system in the condition of the same detector, and the SNR using TDICCD is higher than the one using TDICMOS, CCD and CMOS in the condition of the same optical system.

The intertidal zone refers to the coast between the average highest and lowest tidal levels, which is an important area for researching the dynamics of modern sea-land environments and utilizing the marine resources. The intertidal zone is affected by the dual forces of sea and land, and also human activities. The existing land area remote sensing image processing methods are not completely suitable for intertidal zones, and the accuracy and efficiency of image fusion processing methods need to be improved. A method of the fusion of large scale data remote sensing images for the land and sea intertidal zone is proposed. The logical block is used to divide the image and an image pyramid is established. Through the improvement of different fusion algorithms, the fusion of large scale data remote sensing images is achieved with a high accuracy and efficiency. The experiment was developed to prove that the IHS-NMF algorithm based on the logical block is effective in optimizing large scale remote sensing images.

This paper presents one method and application for remote real-time processing & analyzing of payload data, describes the implementation principle of this method and the details of each functional module in the system. In the first part of this paper, the author introduces the overall architecture design of the system; Then describe the design idea, implementation method and running process of the remote-test-service- platform and remote-terminal in detail; At the same time, the design and implementation of image partition compression technology and data frame format for data communication within the platform are described in detail; Finally, the operation process and operation logic of the platform are introduced. In the second part of this paper, the author introduced the application and characteristics of this system in detail. In the last part of this paper, the author gives a concise introduction to the improvement and optimization direction of this platform. In this paper, the satellite payloads’ remote testing system can able to support the function of real-time processing and analyzing for large amount of data on the remote side, so that the limited expert power can monitoring and testing the satellites been laid on the launching place from the testing hall of Beijing.

With the development of the space industry, the number of space model development tasks has increased significantly. Product warranty requirements are also increasing. Therefore, the Aerospace Model Control Subsystem Product Assurance work also put forward higher requirements. In order to improve the development quality of aerospace model control subsystem, the quantitative evaluation of product assurance in the development of control subsystem is carried out. Evaluation Method of product assurance work quality for Aerospace Model Control Subsystem is a quantitative method based on modern quality management theory and engineering project practice. In this paper, the method is used to quantitatively evaluate the product assurance of a specific type of control subsystem. The evaluation results are in good agreement with the actual evaluation results of the aerospace model of control subsystem. The validity of the quantitative evaluation method is confirmed. It provides the reference for the product guarantee of the follow-up aerospace model control subsystem.

A spacecraft power system design and simulation software is discussed in this paper, which is including satellite orbit analysis module, the solar light ray incidence Angle of solar panel analysis model, and the calculation method of solar array size under the sun light conditions. According to the design parameters of spacecraft orbit and electricity load, the critical design of solar array is developed, and the battery capacity is determined. Simulation of satellite EPS’s energy balance is laid out and energy changes as satellite work on orbit is running on real-time. The battery capacity changing with the real output power of solar arrays and load is calculated. The software is designed in modular, easy to operate, simplifying the spacecraft power system’s analysis, design and simulation.

In this paper, the application of several “design pattern” of object-oriented software development technology in aerospace embedded software development was mainly discussed. aerospace embedded software is the core of supporting spacecraft in orbit, Its quality directly determines the performance and the saftey of the spacecraft. In order to adapt to the improvement and development of spacecraft in recent years, the software becomes more and more complex. “Design pattern” is necessarily adopted to help designing software in order to develop high-quality software with high reusability and scalability. This article focuses on three applicable design patterns. They mainly included the following patterns, including “intermediary pattern” and “strategy pattern” among the “Behavioral pattern” and “bridge pattern” among the “Structural pattern”. They were analyzed aiming at the characteristics of aerospace embedded software and in detail for specific application scenarios. The main purpose of applying these “design patterns” is to solve the problems such as software body architecture design and complex algorithm design, etc.

The direction modulation of electrical thruster’s flow is based on magnetic field reforming which leads to the orientation altering of plasma flow ejected from the helicon plasma thruster (HPT). The theoretical simulation and experiments are carried out to analyze the effect of magnetic field shifting for HPT. Simulation work shows that the magnetic field is adjustable when the magnetic coils change their position. All the Permutation and Combination are listed for Three coaxial coils. Plasma density fluctuates according to an accessional magnetic field generated periodically. The plasma density is about 6*1013 m−3 without any modulation and is from 6*1013 m−3 to 1.5*1014 m−3 when the magnetic field introduced. The plasma flow changes its orientation with 60 degree at most with a modulated frequency which reaches 15 Hz. The reason for the increasement of plasma density is the change of orientation of plasma flow, which verifies that the electric-magnetic coil is effective. More specific work of magnetically modulation and integration will be brought into effect.

A fast response high-voltage power supply for the electrostatic deflection system in a low-energy particle spectrometer is designed. The high-voltage power supply uses high-voltage optocouplers as the core amplifying devices, and the output stage is a two-arm push-pull amplifier composed of two high-voltage optocouplers. The experimental results show that the high-voltage power supply can output either positive or negative voltage from the same output port, and the output voltage range is from −3 kV to +3 kV, which can meet the demand of the electrostatic deflection system for the bipolar voltage supply. The adjustment speed of the output voltage is fast. The time of voltage rise or fall does not exceed 1.7 ms, which can speed up the scanning speed of the spectrometer and improve the time resolution. The output stage adopts a push-pull amplification structure, which can improve the temperature stability of the output voltage. The design satisfies the expected performance of the high-voltage power supply for the electrostatic deflection system.

During the test of the spacecraft, a large number of telecommands need to be injected to verify the correctness of the functional performance. In order to improve the efficiency of telecommand generation and use, this article designs a Lua script-based telecommand quickly generation system. Use Lua language to abstract the model and generation algorithm of various telecommands, design a universal telecommand description method, and shield the variety of telecommand data format diversity; Through the interface functions of C and Lua, the Lua interpreter is compiled into the spacecraft test platform, Interprets and executes Lua scripts to achieve quickly automatic telecommand generation and real-time injection. According to the actual test of a satellite, this method can abstract more than 300 telecommand templates for 4 Lua scripts, and reduce telecommand generation time by more than 90%, greatly improve the efficiency of test verification. It also provides reference methods and practical tools for improving the flexibility of spacecraft telecommand generation.

The “mass, low cost, fast response” development mode proposed by commercial aerospace has become the trend of future aerospace missions. However, the current aerospace software development is twisting with severe issues such as quality, progress, and efficiency, etc., and software product line (SPL) technology turns out to be a good resolution to these issues. Software product line method is one software reuse technology which is oriented to a particular field, massive and in large particle. The method has attracted much attention in the software reuse field in recent years. This paper firstly presents detail discussion on extensive aspect of software product line, such as the concept, theory and methodology, etc. Then after further analysis of the characteristics of software in the aerospace field, this paper points out the application feasibility of SPL and proposes a method of software development and management based on SPL suitable for aerospace field.

Spacecraft operation in-orbit is an important part of the life cycle of the spacecraft. Compared with the spacecraft product itself, users are more concerned about the operation services of the spacecraft. As the ultimate manifestation of the quality of spacecraft products, the stable and reliable operation of spacecraft is always an important indicator of the ability to meet user requirements and provide stable business services. Aiming at the insufficient technical monitoring methods, inadequate service quality, and management efficiency to meet user needs, this paper proposes a standardized management model for multi-spacecraft in-orbit support with refined management throughout the life cycle. Testing results show that this management mode improves the efficiency of in-orbit management, ensures the stable operation of more than 200 spacecraft and achieves the standardized, modeled and professional operation of in-orbit support management. Therefore, it improves the spacecraft operation management capability and user satisfaction, and has important reference value for the spacecraft in-orbit support management work.

All the time integrated modular avionics (IMA) is a hot research topic in fields of aircraft and spacecraft. IMA mainly focuses on the deterministic partition protection in avionics resource sharing, which is the core technology to allow mixed-criticality applications developed by multi-vendors to run on the same system. Firstly, the avionic development before 2010 year is reviewed briefly, mainly focused on the key technologies in IMA. Furthermore, heterogeneous computing and virtualization are surveyed respectively, because they grew most rapidly during 2010 and 2020. The content surveyed cover the background and reasons of the fast growth, the critical technologies and their development trends. Finally, some technology and management recommendations are proposed to promote avionics development in the next decade.

The reaction flywheel is one of the most common actuators in the satellite attitude control, which has a significant impact on satellite attitude. Based on the observer, a finite time control system is designed to resolve the fast stabilization control problem of the spacecraft with the reaction flywheel failure and the unknown disturbance. Using the sliding mode technology, a finite time fault tolerance control law is proposed. Considering the unknown parameters of the actuator effectiveness of the spacecraft and the external disturbance, an observer estimating the interference is designed to improve the disturbance rejection. Finally, the convergence of the designed control system is verified using the Lyapunov function. The results demonstrate the proposed controller has good robustness to the actuator effectiveness and the unknown disturbance.

Due to the characteristics of the lunar rover working environment, in order to ensure the safety of the lunar rover during its operation on the lunar surface, the ground support system is needed to coordinate and assist the lunar rover to complete the mission target selection and execution strategy planning. Based on the task execution conditions of Chang’e-4 rover, this paper develops the overall architecture and system design of the ground support system, and introduces the implementation method of the system. In this paper, the design of the ground support system is proved to be correct and effective from two aspects of the application of the orbit and the completion of the on-orbit support task.

In this paper, a suppression method is proposed from the aspects of principle design, PCB design and structure design to address the issue of radiated noise caused by the use of ARINC659 bus in spaceborne electronic equipments. Through the actual test and analysis, it is concluded that the effective methods to reduce the periodic radiated noise are to ensure the independence of the strong radiated signal and prevent the coupling of the propagation path. Especially for RE102, the effect is very obvious. In order to solve these problems, it provides an effective method. In the future, if further suppression of the radiated noise is desired, a systematic thinking is needed, starting with the scheme design stage to clarify the user requirements, and in terms of component selection, should be appropriately decreased based on the selection principle of good enough to minimize the radiated source and radiated intensity.

This paper presents a method strategy for autonomous mission planning testing, demonstrates a simulation verification system used in ground test and in-orbit application. The task data can be checked for compliance with regulation in various stages. The system can guarantee safety operation, and the whole process is displayed dynamically. Based on the design model and test requirement of the spacecraft autonomous mission planning, the simulation verification system has a complex characteristic of work mode. Moreover, a test and verification strategy for mission planning is proposed for realizing the full process deduction of the complex mission management algorithm of the spacecraft, the satellite-ground integrated interpretation, autonomous safety detection and forecast tracking. The ground adopts the autonomous task scheduling strategy equivalent of the satellite to realize the joint test. The storage form is completely decoupled to generate a highly scalable and generalized system. Furthermore, a reverse rule comparison algorithm is proposed to verify the correctness of the on-board autonomous task development revision. The system is fully intelligence both within a variety of satellite-ground comparison strategies and the synchronous verification method, and can track and forecast task information, and implement functions such as task conflict detection, revision strategy, and use constraint guarantee.

When a high-resolution satellite is imaging on orbit, the relative motion between the sensory optical elements inside the camera may be caused by micro-vibration, which results in degraded images. In order to study the effect of micro-vibration on high resolution satellite imaging, a micro-vibration analysis method of space camera based on target image is proposed in this paper. Firstly, the different factors of micro-vibration which will affect the image quality in different degrees are introduced. Then, the method which can realize the direct measurement of image motion in the image is proposed. The method can analyze the impact of micro-vibration on the space camera directly and get the accuracy number of the image motion, which can provide the basis for the influence analysis of the satellite image quality and the final correction. Finally, we take a factual space camera for example to calculate and analyze the test data by using this model on the condition of the satellite. We get the image motion set by the micro-vibration on focal plane and accomplish the influence analysis method of micro-vibration on high resolution satellite imaging. It is concluded that the proposed method is reasonable and practical. The method proposed by this paper can be referred to for improved design and vibration suppression.

The avionics system is an important part of the spacecraft, and its stable operation is related to the security of the spacecraft. The traditional design generally focuses on circuit and data, such as watch-dog circuit for the processor and error detection for storage date. Because there is no standard module, the unified and systematic management is impossible.This paper proposes a design method of health management for modular avionics systems. The failure detection, health report and failure recovery of heal management for avionics system is based on multilevel functional nodes, tree topology and timing constraint. The functional nodes are defined to provide fault detection and recovery services between the different layers. The detection time is used to constrain the whole topology design.The health management system is designed and implemented in an avionics system of remote sensing satellite, and tested by fault injection. The results from all testing have proved that the design of fault detection and recovery is complete and accurate. The fault-tolerant and self-recovery ability of the avionics system are improved.

Aperture synthetic microwave radiometer (ASMR), because they can obtain high-resolution and wide-width fields of view without scanning, have become a hot spot in the field of microwave remote sensing. Visibility obtained by the radiometer needs to obtain the brightness temperature information of the observation scene through brightness temperature reconstruction. The brightness temperature reconstruction methods directly determine the observation performance of the system. Using the one-dimensional aperture synthetic microwave radiometer to verify the imaging experiment observation results of the prototype and analyze the brightness temperature results obtained by different bright temperature reconstruction methods, it laid the foundation for spaceborne applications.

This scheme makes the best use of structure of the cargo ship by integrating with air-breathing helicon plasma electrical propulsion. The normal operation of a manned space station requires regular replenishment of oxygen, fuel, food and instruments. Research on resupply spacecraft to supply oxygen and fuel to the space station will help reduce the replenishment needs of the station. A resupply spacecraft with air-breathing electrical propulsion as core technology will meet the replenishment needs of the space station during on-orbit operation at a low cost and bring high loading capacity and substantial economic benefits. The replenishment ship based on this scheme can collect 1000 kg working gas a year on 180 km orbit and reduce the cost of building and launching cargo ships. This paper carried out studies on mission process, resource consumption, orbit design and thrust Analysis. The ionization mode of air-breathing electrical propulsion is helicon discharge and the average power for orbit maintaining and air collecting is about 775 W.

In recent years, the number of spacecraft launches has showed explosive growth, the types of satellites have become more and more abundant, and the execution of moving target in orbit has become more complex, the traditional telemetry method has not been able to meet the new requirements, and the visual telemetry has become more demanding. Usually, the execution of in-orbit moving target is short-term and one-time, which is executed immediately after entering orbit. The monitoring requirements of the actuator are short term, with a life span ranging from a few minutes to a few hours. The monitoring camera based on CMOS image sensor is small in size, low in weight, low in power consumption and low in satellite resource consumption, which is just suitable for the monitoring needs of the moving target in orbit. In this paper, the in-orbit target monitoring requirements of CMOS monitoring camera are analyzed, camera parameters are designed, and the application is summarized.

Model-based testing is an important direction of test automation research, the autonomous thermal control function of spacecraft is relatively solidified, the principle is relatively simple, and the test method of autonomous thermal control is universal. In this paper, the autonomous thermal control function of the thermal control subsystem of a deep space probe is selected as the research object. Firstly, the modeling process is introduced. Secondly, the two important links in the modeling process, strategy classification and model definition are described in detail. Finally, an example and the verification results of modeling correctness are given. The result of this model design will greatly shorten the time of test preparation and test implementation, and reduce the test cost. The results of research have great support and reference significance for the common generation selection test in deep space field and the design and implementation of model-based test in other fields.

In space environment, the charge will be collected on the surface of the spacecraft by the combination of the surrounding space plasma and photoelectric effect, forming a suspension potential different from the background plasma environment, that is, the surface charging phenomenon. The integrated monitoring system of plasma environment and surface charging includes 4 parts: omnidirectional electron spectrometer, omnidirectional ion spectrometer, surface potential probe and magnetometer. The main function is to detect the space plasma environment and the surface potential on the satellite, and to process, store and transmit the received signals. Ground testing and calibration have been done for all the four detectors, and the results agree well with the designed value.

Currently, manufacturing companies are actively transitioning to digital models. In view of the many problems caused by the relatively lagging of the spacecraft assembly process technology, this paper analyzes the needs of augmented reality technology applied to the spacecraft assembly process on the basis of the practical analysis of the digital application in the existing spacecraft assembly. This article describes the key technologies of augmented reality technology in spacecraft assembly applications. Finally, two application examples are constructed to verify the application process and advantages of augmented reality technology in specific assembly operations.

The sinusoidal scanning test is one of the common vibration test methods. The purpose is to test the ability of satellites and their components to withstand low-frequency vibration environment by simulating low-frequency transient environment on the ground. However, the sinusoidal vibration test condition is derived from the equivalent calculation of low-frequency transient environment, and there is no such dynamic environment as “sinusoidal vibration” in actual flight. Therefore, it is necessary to study the equivalence of sinusoidal scanning vibration test method and its difference and influence on spacecraft test. In this paper, the equivalence of sine vibration test conditions is analyzed, and the response of a satellite is calculated by using the original transient excitation, the shock response spectrum (SRS) excitation and its envelopment excitation as input. Then, the reasons for the response results are analyzed, and possible improvements and suggestions are given.

Nowadays, information resources have become the most important part of resources in the Internet era, and the problems of information security have become the research hotspot. Channel coding information hiding technology is a new type of information hiding technology, which has been widely studied in the field of communication, but there is little research on the application of spacecraft. Based on this, this paper studies a channel coding information hiding technology based on spacecraft application. In the research, this paper mainly uses the good randomness and security performance of chaotic sequences, applies them to the random coding of encrypted information, and realizes the hiding of encrypted information. In the simulation analysis, it can be found that the channel coding information hiding technology proposed in this paper has good encryption performance, and when the channel bit error rate is set to 5 × 10−3, the recovered information error rate is 0, and the encrypted information can be recovered without error.

With the progress of human civilization and the development of society, aerospace technology is more and more widely used in people’s daily life, but the channel coding based on spacecraft has not been widely used. Channel coding recognition technology is to identify the parameters of the received coding sequence in the case of unknown or known partial prior knowledge, which has a very broad application prospect. It can improve the spectrum efficiency of cooperative communication based on spacecraft and meet the needs of communication reconnaissance. It is necessary to analyze the coding type and parameters of received data, so that the receiver can make effective response. This paper briefly introduces the model, architecture and core functions of channel coding based on spacecraft application, analyzes the structure and function of spacecraft channel coding, introduces the design principle of channel coding system, and explains the necessity of using channel coding identification method for spacecraft. The analysis shows that the channel coding recognition method based on spacecraft has a great development prospect in this field. The recognition algorithm based on Viterbi decoding proposed in this paper has a correct rate of over 97% in 1/3 error resistant codes.

For monitoring MEO (Medium Earth Orbit) space environment on orbit, for acquiring the time and space distribution of plasma parameters and the correlation between space plasma environment and typical surface potential to provide environment detection data for early warning of the surface of charged risk caused by the space plasma environment, for extracting key environment indicators causing surface charging, for building surface charged risk early warning environment standards, two programs were designed that the space plasma detectors working on MEO and GEO orbit, forming high and low collocation. This program starts from MEO and develops on GEO space plasma detection. Therefore, in order to adapt to the changing external environment from MEO to GEO, it is necessary to carry out adaptive improvement and comparative analysis for design (especially for structural design). In this paper, two structural design schemes are compared and their rationality is verified by dynamic simulation from data of modal analysis and frequency response for sine sweeping vibration and mechanical test. The final results and analysis point to a conclusion that the improvement of structure design scheme adapted to the large change from MEO to GEO satellite platform, which gave great support to the space plasma detector.

IQ imbalance is one of the main factors leading to the amplitude and phase consistency of millimeter wave radar channels, which will bring about the interferometric phase error of millimeter wave interferometric synthetic aperture radar (InSAR). In this paper, the problem of IQ imbalance of InSAR receiving channel is modeled and analyzed, the mathematical expressions of IQ imbalance error parameters and interference phase error are derived, the influence of IQ imbalance on interference phase error and elevation error is analyzed quantitatively, The analysis results are very useful the design of spaceborne millimeter wave InSAR system.

To address the issue of actuator failure that may occur in the process of rigid spacecraft docking, a linear sliding mode surface is selected, the corresponding attitude and orbit controllers are designed, and the asymptotically stable fault-tolerant control of attitude and orbit is realized. In the fault-tolerant controller, the health matrix is used to describe the failure of the actuator, and the corresponding substitution value is designed based on the characteristics of partial failure to realize the fault-tolerant treatment of the actuator fault. By using the indirect control method, the nonlinear parts, time-varying terms and the influence of external disturbances of the spacecraft control system under different external conditions are ignored, which improves the stability performance of the spacecraft system. Meanwhile, asymptotic stability of the system conforms to the requirements of spacecraft rendezvous and docking control time. Finally, the effectiveness and stability of the designed control system are verified by simulation experiments and the simulation results are analyzed.

The phase of the modulation data symbol inversion is irrelevant to the pseudorandom noise code, which could seriously destroy the periodic characteristic of the pseudorandom noise code and decrease the acquisition performance of conventional receiver. In view of this, square operation is proposed to add in a commonly used acquisition algorithm. Compared with delay multiplication operation, the probability density function of amplitude is studied. Finally, the constraints and optimal value of the critical parameter are evaluated based on the high dynamic characteristics and the acquisition performance of non-coherent direct sequence spread spectrum system. According to the randomness of the modulation data symbol inversion, the detection probability and SNRout is estimated adopting statistical method on the conditions of different SNRin and information rates. The simulation results show that the acquisition sensitivity of the square operation is 5 dB higher than that of delay multiplication operation on the same detection probability.

Because of the serious electromagnetic interference environments where the displacement sensors work, the wavelet transform method is used to reduce influences the electromagnetic interference. And in this paper, the wavelet fuzzy threshold method is proposed to de-noising, which can overcome the disadvantages of using the hard threshold method or soft threshold solely. Besides, in order to make the estimation accuracy of uncertainty interference higher, the variance estimation method is used to improve the denoising performances. By simulating and analyzing, the sensor signal with serious noise produced by the electromagnetic interference was reconstructed well by disassembled to 6 levels used the sym8 wavelet function. On the basis of this, the noise was reduced by the wavelet fuzzy threshold method. Compared with soft threshold de-noising and hard threshold de-noising, fuzzy threshold de-noising way can restrain EMI better. Finally, the variance estimation method is proved to be able to identify the type of interference signals.

Based on the analysis of control system software automatic test language requirements, this paper proposes a Python-based automatic test language for control system software, which abstractly models the test behavior logic to form a general test script model library and a dedicated test script model library. Testers can write test case scripts by calling the existing test script model, or they can supplement the existing test behavior logic according to the actual test requirements to form a more convenient test script model. The test language can accurately, efficiently and flexibly describe the software testing behavior of the control system, and has the characteristics of easy to master, low test cost, and flexible application. Through the application in the automatic test of spacecraft control software in different fields, the results show that using this test language can execute test cases completely and accurately, which improves the test efficiency and realizes the universalization of the test language.

By simulating the study process in the classroom effectively, a new Improved Teaching-Learning-based Optimization (ITLBO) is proposed to solve multi-parameter optimization. Seeking to improve the converge speed and search quality, two new modifications including the adaptive teaching step size and the self-taught phase are incorporated into the original TLBO algorithm. Firstly, teacher presents nearly the same contents to every student in the teacher phase. Therefore an adaptive teaching step size is adopted to dynamically change the learning step size in accordance with the aptitude of every student, which can speed up the convergence. Secondly, through their interaction with teacher and other students, every students can actively adjust their own knowledge after class. Therefore a new self-taught phase are designed to simulate the knowledge improvement process of students’ autonomous learning, which can enrich the population diversity of learners. Experiments were tested with 8 standard functions. All results indicated that the precision and convergence of ITLBO is enhanced compared to other variant TLBO methods.

As the Chinese Rover of the extraterrestrial surface, the lunar rover is called Jade rabbit. Jade rabbit 1 and 2 separately carry out patrol and exploration on the nearside and farside of the lunar surface. Jade rabbit is obviously different from the traditional spacecraft in the working procedure, which has the characteristics of non-structural lunar environment, un-predictable targets of exploration, no-limitation time sequence and etc. This paper analyzes the working characteristics of the lunar rover and the mission of the exploration. And according to the modular design idea, the working procedure is designed into nine working modes, such as perception mode, locomotion mode, exploration mode, charging mode, sleep mode, eclipse mode and etc. The rover’s patrol and exploration on the lunar surface have been realized through the combination of these nine working modes. In the first two months, Jade rabbit 1 and Jade rabbit 2 had traversed 118.9 m and 120 m separately.

To improve the accuracy of ballistic target tracking, a multi-sensor data fusion algorithm based on Cubature Kalman filter is introduced in this paper. Firstly, the dynamic model of a midcourse ballistic target is established via force analysis of the flight in the Earth Centered Inertial (ECI) frame. The model is then transformed to the local East-North-Up (ENU) frame via coordinate transformation. Secondly, one certain sensor is selected as the information fusion center, and a centralized measurement model is constructed through multi-sensor measurement augment in the ENU frame. Finally, based on the state-space equation and observation equation established previously, a Cubature Kalman filter algorithm is designed to obtain the real-time state estimation of the target, and the tracking effects as well as the algorithm performance are evaluated through Monte Carlo simulations. The results of simulation show that the proposed algorithm can achieve high precision and stable tracking performance of the target.

With the rapid development of China’s economy and technology, spatial infrastructure has been highly valued, and the impact of spatial infrastructure information application is growing. In order to reasonably design spatial infrastructure and make full use of spatial infrastructure information resources, the contribution research of spatial infrastructure information application system should be carried out. Based on the analysis of the basic concept of system contribution degree and the system contribution degree evaluation model, aiming at the contribution degree evaluation of spatial infrastructure information application system, this paper presents the multi task evaluation process and steps, constructs the evaluation index system and designs the system contribution evaluation model. Finally, the implementation process of the contribution evaluation of spatial infrastructure information application system is described in detail through an example analysis. This method can provide technical reference for the study of the system contribution of spatial infrastructure information application system and other systems.

Three-dimensional embedded devices are very good in application, but there are many failure cases. In this paper, we develop a set of DPA methods and procedures through failure cases in recent years.

A novel blind digital beamforming (DBF) method based on complex-valued ICA is presented in this paper. The main idea of this method is to get the accurate estimation of array manifold using complex-valued ICA algorithms (such as CFastICA and JADE algorithms), and then beams are formed with DBF algorithm LCMV. Due to the inherent complex amplitude uncertainty of complex ICA algorithm, it is difficult to obtain an accurate array manifold directly. To overcome this disadvantage, an accurate array manifold can be got by our new method. The array manifold can be estimated accurately and the performance of the blind beamformers is also very well by proposed method in our simulation results with low SNR.

Image quality evaluation method (IQEM) plays an important role in image processing and recognition. In this paper, the structural similarity algorithm of objective digital image quality evaluation method (SSIM) is studied in depth, and evaluate the performance of single and multi-scale SSIM algorithm were compared. Compared to the single-scale method SSIM, the multi-scale SSIM image quality prediction score is more accurate, and is more consistent with the subjective score. The method based on structural similarity for the distorted image is more in line with the characteristics of HVS. The SSIM algorithm combines with the features of HVS, and the edge-based improved algorithm (ESSIM) is analyzed and simulated. The experimental results show that the ESSIM algorithm is more in line with the objective quality evaluation model of HVS characteristics, which provides ideas and directions for the improvement of structural similarity algorithm in future.

Many filtering arithmetic have been exploited to abstracting the ground points from the point cloud datasets lately, and the progressive TIN densification filtering algorithm is the most popular algorithm. But this algorithm is preferably applied in flat terrain. In the rolling area which the terrain ups and downs, it is very hard for the traditional filtering algorithms to distinguish the ground points from point cloud dataset.Based on the classical progressive triangulation filter algorithm, this paper focuses on the seed point re-screening algorithm based on the average height of neighborhood. First, the point cloud data for noise removal, outlier removal, pumping dilute sampling and meshing and other pre-processing operations; Then seed points are obtained and seed points are screened; Finally, we use the filtered seed point to analyze the iterative judgment of the treated point cloud.In this paper, the revised algorithm is used to deal with the test standard data provided by ISPRS. The results show that more terrain features are preserved using the improved algorithm, and lead to the more accuracy than the original algorithm.

As we know, it’s valuable to take reliability validation on the spaceflight products under the condition of zero-failure data. Nevertheless, there have relatively fewer demonstrations based on Weibull distribution. An optimization design method of reliability validation test is researched based on Weibull distribution for improving the reliability of the products. The method can be summarized as follows: The working life and reliability index are primarily assumed. Then the minimum cost is taken as the optimal target, the totality of samples and the proportional coefficients of the test time are defined as variables. Subsequently, the optimal function can be solved according to least squares method, with the numerical values chose reasonably in the scales of the variables. Finally, the optimal scheme can be obtained, in which the calculation result of the reliability index is meeting the given constraint. Example for optimal calculation of zero crossing test of a reaction wheel is presented and the credibility of the suggested method is confirmed. The propounded method can offer some instructions for the design of similar test programming.

The redundancy networks are widely used in the design of communication satellite payloads. Currently, the design of the redundancy switch matrix mainly relies on rebuilding existing matrix based on experience. As the scale of the redundancy network continues to increase, it is difficult for the existing design methods to meet the requirements and ensure the optimal design, which requires both minimum number of switches and compliance of the redundant switching functions. In this paper, the mathematical model of the redundancy network is abstracted based on the graph theory, and the key elements in the model including vertices, edges and connectivity are introduced. A new method of designing the switch matrix is proposed through the Harary graph theorem in conjunction with the method of graphic construction.

The large amount of telemetry data generated during the operation of satellites in orbit cannot be transmitted to the ground in real time due to the limitation of space link. In order to analyze the massive telemetry data in orbit to support intelligent tasks such as autonomous health management., it is necessary to extract the interested telemetry data from the mass memory recorder. Because of the limited processing capacity of the onboard computer, it is hard to read and retrieve data directly from the recorder. In this paper, a telemetry data retrieval accelerator is designed in the mass memory recorder, which is used as the coprocessor unit of the computer module. The data in the memory is filtered by the accelerator at a high speed, and the acquired effective data of interest is submitted to the processor for further analysis and processing. Thus, the processing load of on-board computer is greatly reduced and the high-speed processing ability of mass telemetry data in orbit is achieved, which provides support for the autonomous operation of intelligent satellite.

Due to the nonlinear effect of high-power amplifier (HPA), the constant envelope navigation signal is distorted, which leads to the degradation of navigation signal quality and ranging performance. To solve this problem, the influence of the nonlinear characteristics of the amplifier on the navigation signal quality is studied, and the effectiveness of the predistortion method is verified. After that, the article proposes the signal quality index which is most related to nonlinear distortion. We come up with the corresponding pre-distortion algorithm for memoryless HPA model and memory HPA model. The non-ideal characteristics of HPA will be compensated by pre-distortion technology. In the MATLAB simulation environment, the change of HPA non-ideal characteristics and AltBOC signal index are analyzed before and after pre-distortion. This technology has good results to nonlinear distortion of navigation signal and has great significance of developing navigation satellite signal quality.

Field programmable gate array (FPGA) integrates a large number of computing units and IP cores which can realize specific functions, and has high parallel processing capability. The current spaceborne synthetic aperture radar (SAR) real-time processor realizes high speed acquisition and real-time processing of multi-mode echo data through FPGA. Therefore, it is of great significance to optimize FPGA processing flow and improve FPGA fixed-point processing capacity to improve the performance of spaceborne SAR real-time imaging processor. As a fixed-point processor, FPGA needs to preserve effective data as much as possible in SAR signal processing through appropriate truncation to avoid the resource burden and data storage pressure caused by the expanding bit width. The commonly adopted fixed bit-truncation method and parameter updating on-orbit method cannot meet the application requirements of real-time scene, and cannot meet the requirements of adaptability and accuracy of SAR real-time imaging processing. In view of this situation, this paper studies the bit-truncation technology of FPGA imaging processing, and proposes an adaptive bit-truncation technology based on FPGA, which meets the real-time requirements of SAR signal processor and improves its detection performance and system reliability. The effectiveness of the technique is verified by simulation, and the method has been successfully applied to the on-orbit validation of SAR signal processor.

This paper describes a sample-hold (SH) circuit for the front-ended pipelined 12-bit analog-to-digital converter (ADC). A differential OTA (operational transconductance amplifier) used in the sample-hold (SH) circuit is presented. The OTA is optimized for high-speed high-accuracy applications by using gain-boosted topology. By means of clamp circuit, the slewing rate of the OTA is greatly improved. The design uses the chartered 0.35-μm 2P4M CMOS process with a 3 V supply. The open-loop DC gain is over 110 dB and unity-gain bandwidth is 524.6 MHz. The slewing rate of the OTA is 1160 V/μs while the total load capacitance is 6pf. The SH circuit can settle within 10 ns to an accuracy of <0.01% for the worst case. The SH circuit achieves SFDR of 90.64 dB and THD −89.63 dB with sampling frequency 50 MHz. Design analysis and simulations are presented demonstrating that the amplifier exceeds the specification in the SH stage of a 12-bit pipelined ADC, while dissipating an average of 23 mW of power.

Converged media is increasingly becoming a hot technology which integrates multiple media forms due to the development of the 5G mobile communication technology. With up to 10 Gb/s theoretical downstream speed, converged media, including text, ultra-high definition video, 3D audio and mobile applications, are gradually becoming an important development direction of media technology in China. In this paper, a deep learning based artificial intelligence converged media experimental system is designed and built. Specially, we study the methods and technologies of text generation, processing and summarization in converged media system, with emphasis on the webpage content crawling, speech to text technology application and automatic text summarization. To deal with redundant contents, we present Counting Bloom Filter combined Shingling algorithm (CBFCS algorithm) to filter URLs and near-duplicates text. Scheduling Algorithm is used among multi- servers to deal with a large amount of AI tasks. Extensive experiments confirm the effectiveness of our methods.

Audio classification aims to distinguish different kinds of sounds, and it is of great importance to artificial intelligence applications. Nevertheless, there are still some challenges faced in this field, especially the classification of weakly labeled audio signals. The audio clip contains temporal information and spatial information. However, existing methods only utilize partial information so that the classification effect requires to be improved. To improve classification accuracy, we propose a multi-level attention fusion network (MLAFNet) based on deep supervision which includes multi-attention fusion (MAF) module and multi-level fusion (MLF) module. The MAF module can take full advantage of the information from the time and space domain. The MLF module based on deep supervision strategy can combine the coarse-grained and fine-grained information. Extensive experiments are carried out on the basis of Google Audio Set to demonstrate the effectiveness of the proposed network beyond several state-of-the-art approaches, which achieve 0.970 on AUC and 2.652 on d-prime.

As the product of the high development of digital information technology, video can carry a very considerable amount of information. However, due to its own characteristics, there is often a large amount of information redundancy between and within frames. Through video coding, the redundancy in video can be eliminated by means of compression and coding, which can greatly optimize the storage and transmission process of video. As an important tool in video coding, rate control plays an important role in adapting the output stream and transmission channel bandwidth of the encoder, and has a strong practical application value. In view of the rate control algorithm, the current international mainstream coding standards have done fine design according to the characteristics of their own coding structure. In this paper, the rate control algorithms in HEVC/H.265, VVC/H.266 and AVS2 are described in detail.

In this paper, we study the dynamics properties of the space-based network system which is subject to white noise in a confrontation environment. From the perspective of competition and coexistence, we discuss the balance of three kinds of space-based network systems, including the growth rate and failure rate of spacecraft or satellites in white noise interference systems. First, mathematical tools such as Itô’s formulas are used to derive the balance of the system. Second, we use simple constant coefficient stochastic differential equations to predict and simulate the competition and cooperation of the space-based system, and then the complex system is simplified. Finally, use the discrete method given by Milstein to simulate the solution of the stochastic system. And then, through the numerical simulation, the balance of competition and cooperation of the space-based network system under confrontation environment are proved. In addition, some future research directions are introduced in the conclusions.

In this paper, cislunar integrated communication architecture is proposed for future lunar explorations, which builds a communication network with Earth stations, lunar orbiters, lunar relay satellites, manned spaceships and lunar surface explorers, to support the operation of the robotic and crewed lunar research station planned on the South Polar Region. The proposed cislunar integrated communication system is divided into two segments, which are cislunar space communication subsystem and lunar surface communication subsystem. Key design elements are analyzed for each subsystem in detail, including frequency allocation, modulation and channel coding schemes, multiple access, space data link protocols and network protocols. Based on the design parameters of Chinese previous lunar exploring missions, design suggestions are provided for follow-up cislunar communications.

Quantitatively analyzing the impact of thruster plume’s infrared radiation on Infrared Earth Sensor (IRES) is still an open problem. This article analyzes the temperature and the density distribution characteristics of thruster plume by applying the point source model to quantitatively analyze the impact of thruster plume on IRES. Moreover, the infrared radiation characteristics of non-uniform gas were modeled based on the assumption of Equivalent Molecular Blackbody (EMB), Probability Theory and Planck’s Radiation Law. Furthermore, this paper proposes an algorithm to evaluate the effect of thruster plume on IRES. In addition, simulations on specific application scenarios by combining the infrared radiation model of Earth, the characteristics of the IRES and the spatial position relationship between the IRES and the thruster are conducted in this paper. The simulation results are verified that by employing a relatively simple model with a small amount of calculations, the impact of thruster plume on IRES can be quantitatively analyzed without utilizing professional tools.

Recently, with the observation that fuzzing and concolic execution can complement each other, fuzzing and concolic execution combined method has been widely used for mining vulnerabilities in real world software, while not paying enough attention to the complementary strategy. That is current methods, such as Driller, QYSM, etc., normally use the on-demand strategy to switch between fuzzing and concolic execution engine, which drives down the efficiency of vulnerability mining process. This paper proposed a novel un-touched branch guided strategy to make full use of both fuzzing and concolic execution capability. By combining static analysis and runtime information, we can construct a dynamic set of un-touched and tainted branches, and the corres-pondence test case which can reach the brother branches, and then we can select the best input test case to drive concolic execution, and generate new test cases to cover the un-touched branches. We implement a prototype system FPSFuzz and evaluate our system with LAVA-M dataset and compared it with QSYM. The results show that FPSFuzz found more vulnerabilities quickly and improved the contribution of conclic execution for hybrid fuzzing, which significantly improves the efficiency.

Recently, more and more runtime information such as operands of comparison instructions and parameters of function calls has been used for mining vulnerabilities in real world software, while not paying attention to the difference of those information, which reduces the efficiency of the entire mining process. To make full use of the extracted information, we propose incremental information guided method for binary software vulnerability mining based on the input-to-state correspondence method, which prioritize extract information dynamically by combining static analysis and runtime information, and schedule more computing resource to those related input bytes or execution paths. Finally, we developed a prototype system called FocusFuzz, a grey-box fuzzer for mining more vulnerabilities quickly and efficiently, and we evaluated FocusFuzz on LAVA-M dataset and compared it with REDQUEEN. The experiments show that FocusFuzz find vulnerabilities equally and generate only 3% test cases on average comparing with the original method, which significantly improves the efficiency.

The low spatial frequency error (LSFE) was an important component of the measurement error of star trackers. In order to improve the star tracker measurement accuracy better than 1 arcsecond, the calibration method of LSFE was studied. Firstly, the error composition, source and importance of ground calibration were introduced. Then, the traditional calibration and evaluation methods were described, and the problems in the application of the method to the star trackers which accuracy better than 1 arcsecond were analyzed. Then, according to the consistency of LSFE in a small range of field and the random characteristics of high spatial frequency errors (HSFE), an error separation and calibration method was proposed. Finally, the new calibration method was simulated and verified by experiments based on a sub-arcsecond precision star tracker. The Experimental results show that the calibration residual of the new method is 1.96/100 pixels, which is 38% lower than the traditional calibration method. This method is accurate, stable and reliable, and can be used for ground calibration of various space starlight measuring instrument such as star tracker and star camera.

Solar Array Drive Assembly (SADA) is one of the key components in Attitude and Orbit Control System (AOCS) because its functional capability of controlling solar array has an extraordinary effort on power generation of spacecraft. Since SADA is required to be operated during the entire life-cycle of mission, it is important to implement effective real-time fault diagnosis on SADA for satisfying the power demand of spacecraft when SADA is not working appropriately. This paper proposes a real-time hierarchical fault diagnosis strategy for SADA based on information fusion to guarantee the reliability and safety operation of SADA. Moreover, control strategy for SADA with dual-channel resolver is introduced in this paper. Furthermore, the category of faults regarding to system-level and component-level is analyzed, and simulations based on specific fault scenarios are conducted. The simulation results demonstrate that the fault in component-level or system-level can be diagnosed efficiently and treated properly with the proposed strategy.

Benefiting from the high efficiency use of fuel, the implementation of coordinated control method with ion electric propulsion for frozen orbit can significantly save fuel. Until now, the StarLink and OneWeb companies have sent hundreds of satellites into space. Compared to arriving at the mission altitude directly, the negative offset for altitude allow the launch vehicle to carry more satellites at one time. All of the satellites will climb to the mission altitude, capture the frozen orbit and achieve the phase angle deployment in the constellatin. Complete the three control requirements above at the same time without deceleration maneuver is the best strategy, which can be more quickly with less fuel and less control operations, and more convenient as the speed plus is always positive, which do not require any attitude maneuver when the propulsion is usually located at the –X side of the satellite. Coordinated control method can achieve the mission orbit more convenient with the minimum fuel.

In this paper we study the problem that the uplink ranging signal is not locked when the thermal vacuum test is carried out. Firstly, the failure phenomenon is carefully analyzed and a fault tree is established based on the TT&C transponder design principles and the failure phenomenon, which provides a basis for later analysis. Subsequently, the three aspects of hardware design failure, thermal design failure and software design failure are analyzed respectively, and a series of tests are carried out to verify each failure mode in the fault tree. Finally, through analysis and experiments, the fault reason is accurately located and therefore the failure is perfectly solved. In this paper we focus on the methods of failure analysis, and the entire analysis process is showed out in details. Thus, we not only provide design experience for the development of subsequent TT&C transponders but also for other stand-alone electronic machines.

Synthetic Aperture Radar (SAR) is one of the key components in missile guidance and control system for its functional capability of target identification and scene matching. It is very important to test the SAR system infield by using Radio Frequency Simulation System (RFSS). Since traditional method failed to simulate amplitude and phase modulation caused by antenna pattern and radome exactly, this paper proposes a new concept of using multi-element arrays to radiate electromagnetic wave simultaneously, which can simulate the spatial amplitude and phase features of radar target scattering signal. The simulation results demonstrate that the target signal generated with the proposed method has obvious characteristics of peak shift and sidelobe rise after imaging. And the radar images are more blurred and mottled compared to the old method, at the same time, are more realistic and credible. So that it could be a reference to the practical application of Hardware In the Loop (HWIL) simulation.

With the rapid development of the Internet, the Internet of Things, big data, cloud computing, virtual reality and other applications are emerging one after another. New applications have put forward higher requirements for satellite communications. The use of appropriate channel coding technology can optimize the transmission system. This article aims to discuss the satellite channel coding and modulation technology based on cloud computing, to achieve low error rate and strong anti-noise ability of the coding and modulation system under low signal-to-noise ratio. This paper proposes the application of high-performance LDPC codes to QPSK modulation systems commonly used in satellite communications to form a complete LDPC coded QPSK modulation baseband processing system, and comprehensive simulation and verification of the results show that the coded modulation system is better than uncoded The modulation system has a very high gain, the coded modulation scheme has a gain of 12 dB compared to the uncoded modulation system at a bit error rate of 10−7. The coded modulation system designed and implemented in this paper has strong anti-noise ability, low bit error rate and good stability. It is suitable for low signal-to-noise ratio environment such as satellite communication.

Internet Protocol Television (IPTV) provides users with digital television services, which are based on Internet Protocol (IP) and related value-added services in a low-cost and efficient manner. It combines digital television services and telecommunications broadband services with real-time interactivity, which is welcomed by users. However, in recent years, the development of global IPTV has slowed down, and the growth of the number of users has entered a bottleneck, even some countries have experienced negative growth. As the rapid increase of IPTV users in recent ten years, China has also entered the bottleneck period of development. This article summarizes the development history of IPTV in major countries and regions in the world, especially the development history of China’s IPTV in the past ten years. Based on the current status and existing problems of China’s IPTV market, the research team proposes several suggestions and development directions. We are looking forward to exploring IPTV industry opportunities in the new era and a new future.

5G ultra-dense network can get more cell splitting gain through high-density base station deployment, which has higher spectral efficiency and capacity than LTE. However, the increase of base station density makes the co-channel interference between adjacent cells more serious, and continuous movement of users will cause a lot of handover operations, which will bring a lot of signaling interaction, greatly increase the network burden, and thus reduce the throughput of the network as well as affecting user experience. Considering that the traditional mobility management methods cannot meet the deployment requirements of future ultra-dense wireless networks, a handover management scheme based on residence time prediction is proposed by using the stochastic geometric mathematical model and the derivation of handover triggering probability and average user throughput. The simulation results show that the scheme proposed in this paper has better comprehensive performance than conventional scheme and handover skipping scheme in terms of the average user throughput under different handover decision threshold and base station density.

Coverage issue is one of the key issues of Wireless sensor networks in the Internet of Things, which reflects the situation of a field is monitored or tracked by sensors of the networks. Monte Carlo method is a typical approach to estimate the coverage ratio indicator, which measures how well the sensors cover the region of interests. However, the naive implementation of Monte Carlo method always checks all the sensors for each random sample point and the time complexity of such naive implementation is too large to apply to large scale applications. We propose a novel accelerated approach of the Monte Carlo method based on the geocoding and the related data structure, which supports fast query the nearest sensor or the sensors in a certain range. The time complexity of the proposed approach is deduced compared with the naive ones in theory. Simulation results also show that our approach is faster than the naive version so as to support large scale networks in an efficient manner.

When monitoring highly dynamic time series streaming data, the traditional anomaly detection methods have many disadvantages, e.g., inadaptability to the dynamic streaming data and low detection accuracy. In order to distinguish abnormal data from streaming data, a Markov Process-Based anomaly detection method is proposed. Firstly, the dimensionality of raw data is reduced through Locality Preserving Projection algorithm to bring redundancy down. Then, an Elbow-Based K-Means clustering algorithm is proposed to determine the rational number of mode, and the dimensionally-reduced data are divided into normal and abnormal modes through the algorithm. Finally, a Markov Process-Based anomaly detection model is established to detect the data in abnormal mode, where the effect of concept drift is avoided and a loose mode containing the data in the future unknown mode is introduced into the model to enhance model integrity. Simulation results demonstrate that the proposed method can achieve quasi-optimal performance compared with other contrasting methods.

Aiming at the problem of low accuracy of radar signal sorting in a small sample environment, a sample expansion method based on SMOTE algorithm is proposed. This method uses the Euclidean distance principle for data expansion, so that each sample is synthesized into a new sample, and the impact of the data imbalance on the classifier is reduced in terms of data, thereby improving the accuracy of radar signal sorting. Experimental results show that sample expansion based on SMOTE algorithm can effectively improve the accuracy of radar signal.

A user-define method is proposed in this paper, to help the designer improve the quality of products and shorten the development term. It solves some special coding rule checking problems. The method is implemented by means of Cadence HAL software, Using Verilog procedural interface (VPI) to check Verilog code, Using VHDL procedural interface (VHPI) to check VHDL code, and using common front end procedural interface (CPI) to check common code. The user-define method of coding rule checking includes three steps. The first step is compiling the design using Cadence ncvlog or ncvhdl. The second step is using HAL called VPI, VHPI or CPI to implement the User-define rule. The third step is compiling the User-define rule. The implementation example is presented, and the 24 rules are defined using the method in Practice. The results show that the user-define Method could implement defining rules rather than parsing syntax structure in advance.

Aiming at the main sorting stage of known radar signals in the radar signal sorting system, using supervised learning algorithms in machine learning to replace the traditional sorting algorithms which based on pulse repetition interval. The experimental results show that the supervised learning algorithms can successfully sort overlapping multi-type radar pulse signals, and the sorting accuracy of some algorithms exceeded 95%. It is feasible to apply the supervised learning algorithm to the main sorting stage of known radar signals.

With the rapid development of radar technology, various new systems and new modes of radar are emerging, and radar signal sorting technology is undoubtedly an important part of studying radar signals. This article introduces the radar pulse characteristic parameters and the basic theory of machine learning. And for the radar pulse signals of known categories, PDW is used as the sorting feature, and the supervised algorithm in the machine learning algorithm is used for sorting. The supervised algorithm selects the algorithm based on the probability-based decision tree and the distance-based KNN algorithm to sort the radar signals, and the sorting accuracy rate is more than 95%, which shows the great sorting effect.

In passive remote sensing of the earth, the real-aperture microwave radiometer employs a bulky mechanical scanning platform, which greatly increases the mass and volume of the system. Then, the aperture synthesis microwave radiometer has been developed to alleviate the mass and volume of the real-aperture microwave radiometer. However, the aperture synthesis microwave radiometer has a high complexity in signal processing and system due to it being synthesized by many small aperture antennas. To alleviate the mass and volume of the real-aperture microwave radiometer and the high complexity in signal processing and systemo f the aperture synthesis microwave radiometer, a novel microwave radiometer is proposed, which employs frequency scanning antennas and can observe the scene with electronic scanning, not mechanical scanning. The system structure of the novel microwave is introduced and the main specifications are also analyzed, three receiver architectures for the microwave radiometer used frequency scanning antennas are given and discussed. The calibration method is given. Numerical simulations are also performed to assess the performance of the frequency scanning microwave radiometer.

Nowadays, the NoSQL databases always are chosen to solve the problem of massive semi-structured data storage, but the built-in analysis module still has a lack of real-time data processing. To solve this problem, a real-time storage analysis solution based on Elasticsearch and MongoDB was proposed in this paper. The proposed solution uses MongoDB cluster for real-time data storage and combines MongoDB cluster and Elasticsearch cluster as analysis module to meet the need of real-time analysis. Analysis requirements can be divided into complex statistical analysis and query requirements. Query operations are executed directly in MongoDB cluster, complex statistical analysis such as group statistical analysis, should be done in both Elasticsearch cluster and MongoDB cluster. Experimental results show that in this platform, 99.96% of the storage requirements can be responded in 100 ms and all the analysis requirements can be responded in seconds. Therefore, this solution can meet the need of real-time storage and analysis on massive semi-structured data.

To improve signal quality of wireless enhanced Multimedia Broadcast and Multicast Services (eMBMS), a subspace signal enhancement scheme is proposed in this paper, where MBMS signal is enhanced by subspace filtering at the receiver. On this basis, a signal-to-interference-to-noise ratio (SINR) estimation method is considered to determine sustainable service level of MBMS users. Simulation experiments validate the effectiveness of the proposed schemes.

Polarization modulation is playing an increasingly important role in wireless communications. However, the research on polarization modulation system channels mostly focuses on the modeling of the channel’s channel depolarization effect. As a key component of the polarization modulation system, dual-polarized antennas have rarely been studied. In this paper, we proposed a 2*2 MIMO channel with taking the dual-polarization antennas posture into account. With the help of this channel model, we derived the directional sensitivity and symbol error rate. Through the simulation results, we demonstrated the direction-sensitive nature of polarization modulation systems, which can be used for physical layer security.

In view of the problem that it is difficult to supervise and improve the attention level of teenagers in class in education and teaching activities, based on multi-source data correlation, we combine with big data technology to analyze and research the attention level of teenagers in class. This paper analyzes the collected eye characteristics data of students in the classroom and other personalized related data to conduct a correlation analysis. Then, we derive a set of theoretical models to remind students of concentration improvement, as well as intervention of teachers’ teaching activities. Finally, the proposed theoretical model can improve the teaching quality ultimately.

5G NSA networks are now distributed in many nations all over the world. However, telecom operators have limited ways, like Drive Test, to analysis the network’s performance. In this situation, we will introduce a supervised machine learning based approach to predict the 5G NSA network coverage and performance in a specific area. Our solutions will use the 4G MDT data as the eigenvalue. We firstly use the ML algorithms to analysis the accuracy between 4G MDT data and 4G DT data. Then, select the most important index by analyzing the impacts of 5G NSA coverage and performance. Finally, we will get the rules by training the supervised machine learning model between 4G MDT data and 5G NSA coverage and performance outcomes. The results indicate that the supervised machine learning based approach works well. Telecom operators can use it for the further development of 5G networks.

In this paper, an improved method of mobile terminal location based on Gaussian Markov random model is proposed to reduce the influence of radio wave propagation environment on the location accuracy of existing positioning methods. Through the simulation analysis of the actual data, it can effectively improve the reliability and accuracy of the existing location algorithm.

As 5G Massive MIMO achieves accurate coverage through 3D beamforming, the measurement and evaluation of coverage changes from “cell level” to refinement to “beam level”, which poses a new challenge to network coverage optimization. Therefore, in this paper, the coverage interference and path loss are modeled based on DT data with the help of big data processing methods, and the optimal coverage optimization method combination of Pattern + RF is finally solved through accurate coverage interference prediction and iterative optimization algorithms. This method can improve the accuracy of Massive MIMO coverage optimization, and achieve the most accurate optimization, the highest efficiency, the best performance, and the most cost-effective.

C-band is the most used frequency resource for the 5G development in the worldwide. However, fixed satellite service (FSS) is also deployed in this frequency band in many countries, which will suffer adjacent channel interference from 5G. In this article, we evaluate the interference in the real network deployed by China Unicom. The interference level is determined by network deployment parameters such as the load level of the 5G gNB, the location of the 5G terminals, and the angle between the gNB and the FSS antenna. To avoid the interference, the isolation between satellite and 5G should be improved by increasing the distance or the performance of transceiver. On the other hand, we also need to ensure the flexibility of 5G network deployment. Thus, the method that adding a filter to the FSS receiver is proposed. We test the suitable passband of the filter in the lab environment and verify the effective of this method under the most serious interference in the practical network. Tests have shown that when the filter has 45 dB suppression in the 5G frequency band, the isolation distance can be reduced to 90 m. Therefore, in the actual 5G network environment, the isolation distance between the 5G gNB and the FSS earth station can be further reduced, and a large number of 5G network coverage holes will be avoided.

With the continuous expansion of communication network scale, the cost pressure of mobile operators is further increased. As an important measure to reduce cost and increase efficiency, energy conservation and emission reduction are paid more and more attention by operators. From the perspective of LTE base station energy saving, this paper introduces various technical principles and applicable scenarios of base station power saving, and presents the evaluation method and application suggestions of power saving effect.

Deploying LTE and NR n41 band at 2.6 GHz can resolve both 4G capacity crisis and 5G coverage shortage, and also can accelerate rapid network construction and deployment. Meanwhile, TDD system means a time division system, in which the time slot synchronization needs to be configured precisely in the network. The transmission ratio of the uplink and downlink sub-frame is the same. Also, the uplink and downlink conversion points need remain same.Current 4G network load and handset penetration also need be concerned. In this paper, the network capacity planning in the process of NR n41 in 2.6 GHz band and cooperative LTE-NR networking is analyzed. This paper further plans the time slot alignment to be considered when sharing Active Antenna Unit (AAU) solution in collaborative networking is offered. Meanwhile, the time slot alignment is further planned to achieve NR and LTE interference coordination when the AAU is shared by the cooperative network.

In reviewing the development of extended range forecast, it is not only a complicated scientific problem, but also a technical difficulty, which is challenging in meteorological research. The grid weather operational forecast system for extended range at National Meteorological Center in China is introduced. Based on the ECMWF ensemble prediction system, 5-km grid forecast operational system is developed with these methods including back propagation neural network-self Memory method (BP-SM), Delaunay triangulated method and moving window ordinary kriging method (MWK). Compared daily maximum 2-m temperature forecast of the extended range with ensemble mean and BP-SM method at 2454 stations over China in summer 2018, the results show that the calibrated daily 2-m temperature forecast is significant with the BP-SM method especially over the regions of complex topography. The prospect of research for calibrated technology and development trend in extended range forecast are discussed.

This paper investigates on the problem of fragmentation of a large number of device terminal data faced in precision marketing. We propose a cross-screen tracking algorithm based on user activity data, and realize the Internet business need of identifying different terminal devices of the same user with the user id. The proposed algorithm optimizes the data preprocessing process. More specifically, when the user’s position coordinates are mapped to a manually divided geographic grid, the micro-grid method is used to supplement the semantic characteristics of the position, thereby reducing the loss of information during the transformation of space-time point coordinates. Through the cross-screen tracking algorithm based on user behavior, the proposed algorithm can avoid the dependence of existing technologies for user login behavior or a large amount of third-party platform data. The proposed algorithm can improve the amount and accuracy of cross-screen tracking data, and will reduce exposure costs and increase commercial ROI (Return on Investment) and provide optimal marketing decision support for commercial services.

Aiming at the problem of virtual link priority mapping, the paper proposes a novel candidate path ranking algorithm. The proposed algorithm converts the problem of candidate path ranking into a machine learning binary classification problem. More specifically, the proposed algorithm evaluates the probability that the virtual link is successfully mapped onto the candidate path. All candidate paths are sorted according to probability, and the path with the highest probability of success is selected. The simulation shows that compared with virtual link priority mapping algorithm based on the shortest path, the new algorithm has better blocking rate performance.

In the progress of digital transformation of enterprises and even industries, data plays an increasingly important role. Specifically, business generates data, data feeds back business, and the cooperation between business and data is constantly getting closer. Therefore, we need to do data governance continuously, collect and connect data cross domains, form a piece of standard and accurate data, thus to break the isolated island of data. On this basis, we need to research key business scenarios and demands, mine the value of data, build powerful public capabilities, and support more diverse front-end applications to empower business value with data flexibly and efficiently. In order to achieve above goals, this paper puts forward the concept of big data ecological platform. Furthermore, this paper designs the architecture and introduces the construction practice in the telecommunication operators. Relying on big data ecological platform, it can comprehensively improve the digital collaborative operation level of the enterprise even industry, and gradually realize the transformation the role of data from supporter to enabler to driver for business.

User lifetime value assessment is complex but important which requires continuous observation of users’ behavior with massive time and resource consumption. To overcome the difficulty, this paper improves the RFM model to realize behavior observation and proposes an evaluation model from the perspective of market segmentation based on AHP method. Under real conditions, the model can be used to analyze the comprehensive value of users in two cities as well as the difference of regions and market segments. Results prove that proposed model performs remarkably and has practical significance for service providers.

In recent years, telecom operator builds mobile networks infrastructure worldwide, as well as deploys a series of relevant systems/platforms to management the mobile networks and telecom customers. These systems/platforms can generate a huge amount of data resources. In order to effectively access these systems/platforms and make use of the valuable data resources, this paper designs a novel multi-source heterogeneous data (MSHD) system for telecom operator. The MSHD system contains data access module, data pre-processing module, data storage and management module, data application and visualization module. The MSHD system can assist telecom internal application as well as the vertical industry application.

The intelligent detection of network coverage problems based on the clustering algorithm can automatically, quickly, and accurately locate network coverage problems by analyzing the running data of the existing network, ensuring continuous and high-quality communication services for users. Dynamic AP clustering and DBSCAN clustering algorithms are introduced to analyze MDT data, automatically locate coverage problems, and implement geographic aggregation, reducing labor costs and improving network efficiency.

China Unicom has a global data aggregation and management center, which aggregates rich resource capability, computing capability, model capability, and data capability. In order to meet the demands of enterprise mixed reform and double innovation, the paper adopts mainstream big data technology routes such as Kubernetes, Docker, Hadoop to build a multi-scene capability construction and open platform for large-scale heterogeneous data. The platform encapsulates various capabilities and services, making them open to the outside world. The platform also provides a one-stop container cloud environment for application development and deployment, and supports multiple big data application scenarios. At present, the platform has been promoted and used throughout China Unicom. Besides, it introduced external partners such as Tencent and Merchants Union Consumer Finance Company Limited, involving more than ten industries such as finance, e-commerce, automobile, Internet and real estate. Practice has proved that the construction of this platform can effectively solve the problems of internal capability sharing, intensive management, intelligent scheduling, and maximum utilization, and has important reference value for the construction of the industry’s capability opening system.

In the era of Big Data, more and more Big Data technologies and Big Data products are emerging. Organization of a Proof of Concept (PoC) testing is important for an enterprise to choose proper Big Data products. This paper introduces typical Big Data vendors and their products, and analyzes the process of preparing a PoC testing. It also illustrates how to design test cases for a PoC testing. In conclusion, it emphasizes that testers should have a deep understanding of business requirements and business processes in order to organize an effective PoC testing program.

Along with the development of digital economy and Internet of Thing (IoT), the value network has been instead of traditional business mode, and brings enormous economic parties even some smart devices. The parties need to quickly get the trust from others to accelerate the business trading. Meanwhile each party may have a large numbers account to manage and maintain. This impacted the current identity system. This paper focuses on designing a next generation identity platform, which is un-centralized, data sovereignty, credit system ready and suitable for digital era. Then this paper describes the platform architecture and discusses the key techniques. At the end of the paper, some potential scenarios are introduced which will be implemented in China.

With the implementation of big data strategy in many countries of the world, the data organization and analysis technology has become the main methods for data application and data governance capability. Since data is always organized by specific rules, how to organize information and construct the consolidated rules of data has become an important issue of big data application. However, at present, there is no mature theory of rule and rulebase construction, lack of high-level general rulebase model, and there is no efficient evaluation criteria system for the quality of rule base, which affects the establishment and high-quality management of rulebase. This paper studies how to model and management the rulebase of information resources. First, this paper analyses types of rules and rule relationships according to their functions and semantic properties. Then we propose the requirements for harmonization of rules in the same context. Second, we propose the metamodel of rulebase, and describe the classes and associations of rulebase metamodel. We introduce the internal identifier and composite identifier for rules. Thirdly, we define six measurements for quality control and propose the process of rulebase version control.

Through the deployment of hardware SDN network under Kubernetes, to verify the container environment can rely on hardware SDN network speed limit in the underlying network collaborative, network QOS, network virtualization functions, etc., which could be better filling container network. At the same time. When deploying private cloud, which involves traditional IT infrastructure, IT cloud and container mixed cloud, hardware SDN performs better in network connection during them, meanwhile it can effectively fuse the underlying network and virtualization, and cloud network cooperation. Kubernetes clusters develops rapidly in recently years, it has been deployed in various scenario and has great effect. In most Kubernetes clusters, SDN technology is required only when the enterprise has specific security or configuration requirements. Kubernetes container network requirements can be implemented by using other straightforward technologies. SDN is an additional option to address specific technical issues. In the future, container clouds have a chance to replace traditional clouds.

As a key infrastructure in “new infrastructure”, 5G is changing all aspects of society. In the early stage of 5G construction, it is mainly reflected in the ability of enhanced mobile broadband (eMBB). Firstly, in order to verify how fast 5G real speed, a scheme of 5G speed test platform was proposed. Then, the principle of speed test was simply analyzed, Finally, through the analysis of the speed test log using Tableau visualization tools, we found some statistical features from the datasets, and the 5G average uplink and downlink rate of ten cities in China were revealed, which help us estimating the progress of the NR construction and 5G business development of some operators.

Traditional mobile communication network plan depends on simple data analysis and manual judgment, which is easily influenced by the personal experience and ability. To fully use the data and avoid manual error, intelligent plan becomes the trend. The paper proposes an intelligent mobile communication network plan method with insight big data. With call record, personal position and measurement report data, machine learning method is adopted to design the network. From the collected data, it can be summarized into 7 dimensional insight big data, including service coverage rate, communication capacity, business income, complaint hot topics, user distribution and occupancy rate. With the final target, mobile sensitive algorithm, LSTM based call traffic prediction and suppressed traffic recognition, accurate site planning, XGBoost based 5G user profile and other methods are adopted. It has been successfully applied in the 5G communication network plan of Shandong Unicom. 2466 5G stations have been established and the efficiency has been increased significantly.

Electronic toll collection (ETC) is an electronic non-stop toll collection system for expressways which brings drivers huge convenience when vehicle passes through the toll gates without stopping. Recently, China has a huge market and its credit card business has greatly contributed to the retail business of banks. Therefore, accurate marketing for the potential users is very important for the banking business. Users can be fully portrayed to explore the characteristics of potential ETC users based on telecom big data. Under such situations, we propose an advanced K-means clustering algorithm in view of silhouette coefficient which can distinctly increase the accuracy of clustering and improve the performance of k-means clustering. By applying this advanced algorithm in the precision marketing scenario of ETC credit card, the key elements, which affect customers’ ETC processing, can be obtained. This method brings new ideas and new momentum to the development of vertical industries.