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Über dieses Buch

This book collects selected papers from the 28th Conference of Spacecraft TT&C Technology in China held on November 8-10, 2016. The book features state-of-the-art studies on spacecraft TT&C in China with the theme of “Openness, Integration and Intelligent Interconnection”. To meet requirements of new space endeavors, development of spacecraft instrumentation systems have to follow an open concept and approach in China. An open spacecraft instrumentation system encompasses integrated development of different types of services, integration of disciplines and specialties, intelligent links, and more scientific and intelligent information interface technology. Researchers and engineers in the field of aerospace engineering and communication engineering can benefit from the book.

Inhaltsverzeichnis

Frontmatter

Spacecraft TT&C Science and Technology

Chapter 1. Discussion on Networked and Integrated Space-Ground Information System

For application needs of effective information delivery and exchange between space and ground network nodes in space-ground network, an integrated multi-function common platform based on information integration technology is implemented and a resource pool for space-based and ground systems is constructed using software defined network (SDN) architecture, network protocol, and route gateway in order to remove information block caused by physical border around nodes within network. It’s an integrated space-ground information system with function and physical resources virtualization and intelligent information flow. It enables improvement of space-based information resource utilization, information tailoring by demand and effective information sharing capability. Based on space-based information system development trends, application advices and development focus of integrated space-ground information system are proposed, and key technical development directions are discussed.

Jianping Hu, Huizhong Xu, Ting Li, Tian Liu, Hongjun Yang

Chapter 2. Preliminary Discussion on the TTC and Management of Commercial Space in China

The vigorous development of international commercial space drives the rise of the domestic commercial space. In order to actualize the efficient management of commercial satellites, this paper researches the development situation of domestic and foreign commercial space and commercial space TTC, analyzes the enlightenment of the development of foreign commercial space and space TTC to China. It is concluded that the general trend of TTC and management development is diversified, and it is imperative to moderate encourage the development of commercial space TTC. Preliminary discussion has been carried out, on strengthening strengthen space legislation of commercial space TTC and management in China, exploring the new commercial space TTC and management model, and enhancing the management of commercial satellite services. The proposals have been put forward, of that space rules should be made at national level, and industry standard level, satellite mission center should support external connection to satellite TTC center, international cooperation of commercial space TTC ground station should be strengthened, and the ability of the management and services on frequency management, orbital resource, space object catalogue, and launch & recovery should be improved.

Aimin Xu, Guoting Zhang

Chapter 3. The Deputy Reflector Control Technology of the Large Deep Space Antenna

The aperture large and working frequency high of the deep space detection and control antenna, the electrical performance degradation can not be ignored, because of the deformation of the main and deputy reflectors. The solution to this problem is to use the deputy reflector control technology to realize the antenna electrical performance compensation. Firstly, on the basis of analyzing the mathematical model of parallel mechanism, the forward and inverse solutions of the position and attitude of 6-DOF parallel mechanism are given by the definition of parallel mechanism coordinate system. Then, according to the deformed shape, the relationship between the position and attitude of deputy reflector and the pitch angle is given using the parabolic fitting method, in real-time motion process, according to the pitch angle to find out the best working point of the deputy reflector position and attitude. Finally, control of the deputy reflector to the best position and attitude, by the 6-DOF parallel mechanism forward and inverse solutions and the control algorithm. The theoretical analysis and engineering practice show that the control technology of the deputy reflector can achieve effective compensation for the antenna electrical performance, by controlling the centre point of the deputy reflector to reach the best position and attitude. Strong bearing capacity and flexible control features of the position and attitude, the 6-DOF parallel mechanism of the deputy reflector can achieve real-time precise control.

Lujian Zhang

Chapter 4. The Study on the Adjustment Model of Sub-reflector and Engineering Realization Method

The gravity deformation of large reflector antenna causes the deterioration of antenna performance. In order to solve the problem, the method of real time adjustment of sub-reflector to reduce the influence of gravity deformation is proposed in the paper. The influence of the position translation and rotation of sub-reflector on antenna gain and pointing is analyzed. The mathematical model about the posture change of sub-reflector with the adjustment of antenna elevation angle is built. A set of data about the main reflector deformation of 35 m antenna for different elevation angles was obtained through digital photogrammetry. The best fit was conducted. And then a set of optimum position coordinate of sub-reflector obtained through best fit were superposed with the measured displacement data of sub-reflector under the action of gravity with respect to different elevation angle. And then a set of final adjustment data of sub-reflector was obtained and substituted into the mathematical model. The best fit was conducted again by using the least squares to calculate the parameters of mathematical model. The model was used to adjust sub-reflector in real time to reduce the influence of gravity deformation on the antenna performance. The simulation results show that the gain of 35 m antenna in X and Ka band can be increased by 0.52 and 1.95 dB after the sub-reflector position is adjusted in real time by using the model.

Yuhu Duan

Chapter 5. Experiment and Performance Analysis of Iterative FX Correlation Combining Algorithm for Arraying in Deep Space Network

Downlink antenna arraying is an effective method to improve the ground receiving capacity instead of the large-aperture antenna in the future deep space explorations, and that the arraying combining algorithm is the key factor in influencing the system performance. In allusion to the problem of the efficient combination under the lower SNR conditions at a Martian distance, an iterative FX correlation combining algorithm is proposed. The principle and performance of the algorithm are discussed and compared in detail, and the arraying application of the algorithm is presented in the CE mission. Simulation and experiment results intimate that adaptive FX correlation combining algorithm has a better performance than other arraying methods such as FSC and BC, and is acceptable for the arraying combining of the Martian weak received signal.

Youyong Liu, Hujun Geng, Suli Guo, Weijun Yang

Chapter 6. Research on RF Link Management Technology of Telemetry Network System

The physical structure of Telemetry Network System is introduced first in this paper. Except the traditional telemetry downlink, a new bidirectional data link is developed so that the test articles and the ground stations can form a telemetry network. Then the principle and process of RF link management are discussed. Because the link manager should assign transmission opportunities based on network capacity, two kinds of dynamic capacity allocation algorithms—B-LM and E-LM are studied and compared carefully. Both B-LM and E-LM algorithms can coexist in the link manager, either statically configured or dynamically switched depending on network conditions. At last, the software architecture is analyzed briefly.

Xinglai Wang, Kun Lan, Guojiang Xia, Ming Han

Chapter 7. Analysis of Radar Signals Induced by Symmetric Antenna Interference Region of Transponder

For researching the effect of signal interference induced by symmetric antennas of the rotating target with the velocity measurement radar (VMR), we analyzed the factors including AGC, Doppler, micro-Doppler and error voltage of VMR in theory in this paper, and proposed a method for compute the difference of Doppler between before and after the interference region. Then processed the radar data to find secrets about the factor of AGC, Doppler and error voltage when radar antennas are in interference region, obtained the micro-Doppler and its period using the method of wavelet transform and auto-correlation. There was a conclusion through theoretical analysis and data validation, that is, the AGC value fluctuated greatly with a descending range of 10~20 dB, the Doppler jumped greatly, and the error of voltage enlarged obviously when radar antennas in interference region, the micro-Doppler appeared two peak values (positive and negative) at the moment before and after the interference region.

Bo Yang, Lianwen Meng, Yunfeng Liang, Yongsheng Zhang, Hui Zhou

Chapter 8. Deep Learning for Mid-term Forecast of Daily Index of Solar 10.7 cm Radio Flux

For the mid-term forecast of daily index of solar 10.7 cm radio flux with deep learning method, a neural network based on the classical multi-layer perception model is proposed. The network contains only one hidden layer with 90 neutrons, and an autoregressive model of time series is implemented non-parametrically. In the forecast, the historical daily indices as well as the historical forecast error are considered. The model gives the forecast of next 27 days with the values of past 27 days. The networks are trained and validated with historical data over 50 years, and the result clearly shows that compared to the traditional methods, the mean relative error is significantly reduced. Unlike most of the previous studies, in which the model parameters need to be rolling updated, while with this model the parameters are fixed after the training. The proposed model greatly simplifies the daily operation of forecast, and is extremely advantageous to the promotion in other applications.

Xin Wang

Chapter 9. The Analysis of the Semi-major Axis Changed by the North–South Control of the Beidou GEO Satellites

During the north–south control of the BeiDou GEO satellites, due to the influences of some factors, such as the gyro drift, attitude control and orbital plane change, the semi-major axis is changed, which causes the ground longitude of satellite to drift. It is hard to accurately estimate the effect of north–south control on the semi-major axis in practice. According to the north–south control characteristics of the GEO satellites, the reasons of various factors affecting the semi-major axis has been analyzed. The model of various influencing factors on the semi-major axis is established by stripping the factors. The accuracy of the model is verified by using the data of the previous north–south control of GEO satellites in orbit. And the magnitude of each influencing factor is given. The results show that the estimated error of the model is less than 1 km. The model can be used to compensate the semi-major axis in the north–south control of the BeiDou GEO satellites.

Quanjun Li, Rui Xue, Dalin Kong

Chapter 10. Autonomous Orbit Determination of Satellites Around Triangular Libration Points in the Earth–Moon System

Recently, people are proposing to build a deep space navigation constellation in the earth–moon system which utilizes libration points of the Earth–Moon system. In a recent paper of the authors, two special stable orbits called as dynamical substitutes (DSs) around each triangular libration point (TLPs) are given in the real earth–moon system which is perturbed by the Sun. Due to their stability, orbits around the DSs are ideal for locating the navigation satellites. Theoretically, the orbits of the navigation satellites can be autonomously determined by only using the inter-satellite range data. As a result, no support from the ground stations is needed, and the navigation constellation can autonomously perform their roles in space. The current work is devoted to this problem, i.e., the autonomous orbit determination (AOD) between satellites locating around the DSs which are circling around the TLPs. Studies show that in order to obtain good AOD results, the data length should not be too short, and the satellite should have motion component perpendicular to the Moon’s orbital plane. The current study can be used when deploying the navigation constellation in the earth–moon system.

Bin Liu, Xiyun Hou, Jingshi Tang, Lin Liu

Chapter 11. Orbit Maneuver Detection Based on Space-Based Angle Innovation

Methods of orbit maneuver detection of space targets are studied in this paper based on the space-based angle measurement innovation, which aim to acquire a real-time or nearly real-time awareness of space orbit maneuver. First, the EKF model for evaluating space target motion is presented, which only uses the space-based angle measurements. Second, the innovation characteristic of the space orbit is investigated with a maneuver considered or not. Four methods of orbit maneuver detection are brought forward which are based on the hypothesis test on the distribution characteristic or parameters. Finally, the methods are compared using numeric simulations. The results show that the success rate larger than 80% can be achieved by three methods, i.e., the innovation and noise comparison method, the innovation comparison method and the normalized innovation method. Furthermore, the method of normalized innovation can achieve a success rate larger than 90% for a not too little maneuver. The research is beneficial to the construction of our space situation awareness system.

Lei Liu, Jianfeng Cao, Ye Liu, Songjie Hu, Geshi Tang

Chapter 12. A Simulation Study of Orbit Determination for Lunar Probe via Relay Satellite

Chang’E-4 will be the first to achieve a soft landing on the far-side of the moon. The tracking and data transmission for Chang’E-4 will depend on a relay satellite on a Lissajous orbit around the Earth–Moon L2 point, and the four-way ranging measurement is expected to be obtained. The capability of orbit determination for Chang’E-4 is studied by simulation. The results show that the relay satellite can realize a near full time tracking for lunar probe. In terms of the orbit determination capability, the orbital accuracy of relay satellite is an important constraint. Once the tracking arc reaches 5 h, the orbit solution for lunar probe tends to be stable. However, the orbital accuracy is still one order of magnitude lower than that of relay satellite. For inter-satellite tracking, the stability of the satellite clock is another constraint. With 1 h auxiliary ground station tracking every day, an orbital accuracy of 100 m can be achieved.

Jianfeng Cao, Lei Liu, Ye Liu, Weigang Su, Songjie Hu

Chapter 13. A Multi-dimensional Genetic Algorithm for Spacecraft TT&C Resources Unified Scheduling

Many researches at home and abroad applied genetic algorithm (GA) on the problem of space tracking, telemetry and command (TT&C) resource scheduling, which is a kind of time window limited constraint satisfaction problem, and many good effects are achieved. But these works mainly focused on the low earth orbit (LEO) spacecraft which has a short visible pass and the total pass is tracked usually, without considering the high earth orbit (HEO) which has long visible pass and usually only part of it is tracked. In this paper aiming at the characteristic of spacecraft TT&C resources unified allocation for HEO and LEO spacecraft, a multi-dimensional genetic encoding method is promoted to describe this problem. The corresponding elements of the algorithm including crossover operator and mutation operator are defined as well so that a multi-dimensional GA is built to solve this resources allocation problem. The simulation results show that this algorithm could solve the problem of TT&C resources management and unified allocation for LEO and HEO spacecraft effectively, as is confronted with the current domestic managing mode of “one net for multi-spacecraft”.

Jian Bai, Huili Gao, Xiaosong Gu, Huiying Yang

Chapter 14. Research on Health State Evaluation Method of Ground-Based TT&C Network

For the purpose of mastering the overall health state of the ground-based TT&C network, a health evaluation model for ground-based TT&C network is established according to the characteristics of the ground–based TT&C network. The method that using the difference between the measured value and the standard value of the indexes to evaluate the indexes is proposed, the indexes of the three modules(control center module, TT&C nodes module and communication links module) that can influence the health state of the ground-based TT&C network is analyzed, the weight of each evaluation index for the evaluation model using the AHP is determined and standard value for each index in the operation of the ground-based TT&C network is gave. Based on 2015 S-band TT&C equipments and on-orbit spacecrafts to evaluate the health status of S-band ground-based TT&C network, the evaluation results are that the health index is 88.32% and the health level is good. The results show that the proposed evaluation method can determine the health status of the ground-based TT&C network directly and can be used in the operation management of the TT&C network.

Tao Wu, Huili Gao, Junchao Chen, Yindi Wang, Huiying Yang

Chapter 15. Space-Ground TT&C Resources Integrated Scheduling Based on the Hybrid Ant Colony Optimization

Space-ground TT&C resource integrated scheduling problem (TTCRISP) is a representative of large combinative optimization problem, and its optimization process is very complicated, single ant colony optimization (ACO) strategy has disadvantage of low efficiency and poor performance. For this reason, this paper proposes two different serial structure hybrid approaches which combine ACO with genetic algorithm (GA) to tackle TTCRISP. GA is used to accelerate the low optimization efficiency due to the lack of pheromone in the early processing stage of ACO and to prevent premature convergence. Results indicate that the new method performs better than the previously presented methods from the subjective and objective viewpoints and is a viable and effective approach for the space-ground TT&C resource integrated scheduling problem.

Zexi Li, Jing Li, Wenting Mu

Chapter 16. Design and Realization of the Three Layers Telemetry Data Transfer Software Frame

According to characters of multiple data kinds, flexible data receiving and sending modes, frequent techno-state changes and a high standard software maintenance, a “three layers data” transfer software frame with highly abstract data, high generalization degree disposal process and strong adaptability was proposed in this paper. At present, the telemetry data transfer software has been implemented in the Kylin operating system based on this frame. All kinds of aerospace measurement task demands can be meet through quick and visual configuration. Practice shows that this frame is one ideal and efficient general solution of data transfer software and can be promoted to radar, optical and other measurement equipments.

Guanghui Ren, Xiangyu He, Shuangcheng Gao, Xin Zhang

Chapter 17. Telemetry Communication in Complex Attitude Conditions Based on Space-Time Coding

In order to improve the reliability of the aircraft telemetry communication in complex attitude conditions, a system model with concatenated LPDC space-time codes and a 2 × 1 antenna system is established. A channel parameter estimation method is introduced, and then a soft space-time decoding algorithm based on channel parameter estimation is proposed. The decoding algorithm gives soft output information to the LDPC decoder which can take full advantage of LDPC coding gain. Simulation result shows that there would be a poor error performance without space-time coding while the phase difference of signal from two antennas is in the vicinity of π. But with space-time coding, the reliability of communication in any phase difference could be guaranteed.

Hongpeng Zhu, Jun Cai, Zhiqiang Li, Zhongwu Xiang

Chapter 18. Development of the Lunar-Earth and Deep Space TT&C System with Several Key Techniques

This paper analyzes the present research status of the lunar-earth and deep space telemetry, track and command (TT&C) system, four major difficulties and challenges to establish the TT&C system are studied. Then urgent needs for antenna arraying technology, laser TT&C technology, Ka and millimeter-wave band hypothermia receiver, superconducting nanowire single photon detectors, deep space optical tracking system, narrow linewidth laser source generating technology, optical communication modulation technology and high-power low-noise amplifier were summed up. A latest cutting-edge technology for deep space TT&C system, namely the iROC (integrated radio and optical communications, iROC) system was described. Finally, with the current situation, the recommendations of future developments of the lunar-earth, deep space TT&C system have been put forward. The research results can supply references for the development of the lunar-earth, deep space TT&C system.

Haifeng Yang, Lin Chai, Ouxin Lu, Jianping Hu, Maoge Xu, Hui Yan

Chapter 19. An Improved MFSK Signal Detection Algorithm for Mars Probe Entry, Descent, Landing Phase

To solve the high computational complexity problem of carrier recovery enhancement for Maximum-Likelihood Doppler shift estimation algorithm (CRE-ML), the relationship between four searching dimensions and carrier recovery enhancement is analyzed. A time-domain matching-average periodogram algorithm based on 4-dimensions searching (4D-TDMAP) is proposed which decreases the algorithm complexity by reducing the Doppler rate matching accuracy requirement. Simulations are performed when the maximum Doppler frequency is 50 kHz, Doppler frequency rate varies from −1000 to 1000 Hz/s, which refers to the high dynamics during the EDL stage of Mars Science Laboratory (MSL). The results show the proposed algorithm reaches the same performance as the CRE-ML does with its computational complexity decreased to 0.26%, and its MFSK signal detection threshold decreased by up to 3 dB compared with traditional time-domain matching-average periodogram algorithm.

Tiansheng Zhang, Xiaolin Zhang, Zan Li, Junhai Bao

Chapter 20. Robust Fault Detection for a Spacecraft with Lipschitz Nonlinear System

This paper presents a sliding-mode observer based method of actuator fault detection for a class of Lipschitz nonlinear systems with unknown disturbances. Through equivalent state transformation, the state equation of the system is partitioned into two parts. The first sub-system is involved with both actuator faults and unknown disturbances while the second is only involved with actuator faults. Then we design sliding-mode observer for the first sub-system and linear observer for the second sub-system, respectively. When no actuator faults occur, the observers are able to track the system state asymptotically. And the output error can be viewed as residual to detect the actuator faults. By using such a detection method, the strong conditions to reconstruct the faults based on equivalent output injection can be removed. The simulation results to a simplified dynamics of the High Incidence Research Model spacecraft show that the proposed method is effective.

An Liu, Zhibin Wu, Dong Han

Chapter 21. Human Motion Capture Similarity Control for Space Teleoperation

For the lack of flexibility of traditional space teleoperation control method, an adaptive terminal sliding mode similarity (ATSMS) control method is proposed. Based on the end position and joint angle data of the operator’s arm captured by motion capture technology, an adaptive terminal sliding mode controller is designed in this method to control the end position of space robot accurately. Besides, a clamping velocity is designed, and then a similarity control method is used to control the robot’s joint angles to tend to the operator’s arm without disturbances to the accurate control of the end position. Numerical simulation and ground experiment results show that, the proposed ATSMS control method can realize the accurate control of the end position and the flexible control of the joint space, in which the end position control accuracy is about 97.58% and the average similarity between the operator’s arm and space robot is up to 99.06%. Thus, the ATSMS control method can increase the flexibility of space teleoperation and be applied in the future for more precise and complex space teleoperation tasks.

Zhong Shi, Xuexiang Huang, Tianjian Hu

Chapter 22. Analysis and Design of the Stabilization Loop for Ship-Borne Antenna Servo System

To improve the ability of the ship-borne antenna servo system to isolate the ship’s shaking, the stabilization loop that uses gyroscope as the feedback element is the commonly used, but choosing frequently-used PID regulator as a form of its regulator often cannot obtain satisfactory result, hence, the form of regulator that uses PID + integrator + lag compensation is put forward in this paper, and the parameter debugging depends on the rise time of the stabilization loop through analyzing the bandwidth and response speed of servo loop. After the completion of the regulator, sinusoidal signal that amplitude is 8° and cycle is 10 s is added in the system as ship-swaying to verify the effect of the scheme, the result of the experiment is that the tracking error of azimuth axis of the antenna decreases from 0.1° to 0.05°, and the tracking error of elevation axis is reduced from 0.24° to 0.049°. It shows that the approach that puts PID + integrator + lag compensation as the form of the regulator of stabilization loop is correct and effective.

Jianhui Jia, Shuyang Zhao

Object Exploration and Identification

Frontmatter

Chapter 23. Target Recognition of Radar HRRP Using the Envelope Reconstruction

In target recognition based on high range resolution profile (HRRP), the major challenge is to extract invariant and robust features from the measured high dimension range profile samples. Focused on the reduction of dimensionality, a novel algorithm for extracting HRRP features is proposed in this paper, and the Legendre moments with orthogonal and translation-invariant properties was adopted. The proposed algorithm utilizes the average HRRP in aspect-frame, and then preprocesses the HRRP with amplitude ℓ1 normalization. The Legendre moments are calculated with mapping range values into orthogonal definition domain to provide invariant feature vectors. Meanwhile, spectrum analysis (SA), which can be regard as first-order approximation of relax algorithm, is adopted to reconstruct the real HRRP obtained by inverse fast fourier transform (IFFT) in order to desensitize moments in low SNR environment. Several experiments with four different targets measured data demonstrate that Legendre moments features with flexible maximum order to be chosen have significant advantages over central moments. SA can provide a more robust recognition performance in low signal noise ratio (SNR) environment as 5 dB compared with those of HRRP directly obtained by IFFT.

Pengfei Zhang, Li Chan, Hongxi Zhou, Xiaguang Yu

Chapter 24. An Improved Adaptive SRCKF Algorithm for Non-cooperative Target Orbit Determination

In this paper, a novel filtering algorithm for the orbit determination of non-cooperative target is proposed to cope with the simplified dynamic model error problem. The algorithm is based on the nonlinear predictive filter (NPF) and the square root cubature Kalman (SCKF) filter, called adaptive square root cubature filter ASRCKF). In the filtering process, NPF is used to modify the orbit dynamic model and SRCKF takes the revised model for state estimation. The simulation results validate the proposed algorithm has higher tracking precision, stronger robustness and stability than traditional filter.

Guangde Xu, Zhongqiu Gou, Bainan Zhang

Chapter 25. Influence Analysis of the High-Energy Electrons on Geosynchronous Orbit Satellite

In order to clarify why there is abnormal appearance of GEO satellite, and improve the reliability of the satellite, this paper introduces the mechanism of the earth’s radiation belts and energetic particles first, which leads to the fact that GEO satellite is in bad space environment. Then based on the monthly space environment data from the Chinese academy of sciences for Space Environment Prediction Center (SEPC) and National Satellite Meteorological Center (NSMC), combined with the fault data from one GEO satellite, by statistics and analysis, it comes to the conclusion that the high energy electrons in the earth’s radiation belts is a major cause of GEO satellite fault. Next according to the theoretical analysis, the conventional prediction and special prediction, the prediction technology of high energy electrons is discussed. In order to enhance the accuracy of satellite fault prediction and the ability of space situation awareness, reduce the risk of long-term management and the personnel pressure, it’s necessary to strengthen the high energy electrons real-time prediction, which is in the space environment of GEO satellite.

Zhenghe Wang, Baosheng Sun, Shengpeng Liu

Chapter 26. Image Fusion Method Based on Sparse and Redundant Representation

In order to obtain the fusion image which can provide more information, a new method of image fusion based on sparse and redundant representation theory is put forward. In the method, first of all, the original image is represented by a redundant dictionary as a sparse coefficient. Then, the sparse coefficients are fused according to the absolute-max fusion rule. Lastly, the fused image is reconstructed based on the merged coefficients and the redundant dictionary. The method proposed in this paper is compared with some traditional methods on some space targets images. They are laplace pyramid fusion method, principal component analysis fusion method, discrete wavelet transform fusion method, curvelet transform fusion method, and non-subsampling contourlet transform fusion method. The experimental results show that the proposed method has better performance both subjectively and objectively.

Jianglin Shi, Changhai Liu, Rong Xu, Tao Men

Chapter 27. An Improved Test Method to Study the pBRDF of the Rough Surface of Targets

This paper introduces a test system and a new method to measure the Stokes parameters and the data of the pBRDF matrix of the scattering light. The test system is a two-dimensional turntable system and the test method using the system makes it more effectively and reasonably to test the bidirectional scattering data of the rough surfaces of the fundamental materials. The work is demonstrated by experiments. The samples we used in the experiment include the standard reflector and the green coating on the surface of the aluminum plate. The experimental results verify the accuracy and effectivity of the proposed method, which will be the supporter of the study of the pBRDF model of targets by much more accurate experimental data. The experimental data also showed that the application of polarization imaging technology can effectively improve the ability of target detection and recognition.

Qing Liu, Yonghong Zhan, Di Yang, Yaping Wang, Change Zeng

Chapter 28. Study on the Geometric Super Resolution by Code Division Multiplexing Technology

In the imaging system for sense, the optical systems could realize the high space resolution, however, the overall optical systems resolution included the detector is limited by the CCD’s nonzero pixel size. The image sampled by the detector might not meet the requiring of the sample principle of Whittaker–Shannon, which would induce the frequency aliasing. In the frequency field, the different frequency image could be coded by a special designed orthogonally coded, then, the sampled image could be transformed to frequency field and decoded by the designed code, and the frequency should be no-lose. In this scheme neither the CCD nor additional elements are moved, and the noise which caused by the optical system should be depressed. The mechanism of the super-resolution by code division multiplexing was simulated and the result of the simulation was analyzed in the paper.

Di Yang, Xinyue Liu, Change Zeng, Yonghong Zhan

Chapter 29. Processing the Reflectance Data of Rough Surface for Inversing the Index of Refraction

Inversion of the complex index of refraction will influence object’s polarized characteristics. In this paper, a new method is proposed based on Vimal–Milo method. Analyze the characteristics of reflectance from rough surface and point out the defects of the current methods which avoids the unpolarized component when calculating. Analyze the relative polarized component, derive the inversion model, and devise an algorithm for the optimum solution of the formula using Hooke–Jeeves method. Carry out the inversing and forward simulation using the measurements of the polarization for green paint and Aluminum. The inversing data shows that the precisions are highly improved by 37.8 times and 10 times than Vimal–Milo method, and errors are well within ±0.01, while the forward data shows that the error of green paint decrease 24 times and errors are within 0.0055.

Yonghong Zhan, Di Yang, Qing Liu, Change Zeng, Yaping Wang

Chapter 30. Polarization Optical Image Processing Used in the Target Detection and Identification

Optical image processing is an important part of photoelectric detection, but the frequently-used method is limited in the condition of complex background, so this paper introduces a thought to improve this problem that the optical image can be made polarized in order to get pictures of polarization intensities and pictures of degree of polarization. At first place, it makes an analysis of polarization of light, and points out there are obvious differences of reflected polarization characteristics between target and background which can be used to distinguish different things. Then it makes a simulation of reflection from the surface of the green paint and aluminum, and shows that the green paint has bigger degree of polarization than aluminum while smaller index of reflectance. At last, it does a series of outdoor experiments and verifies that the polarization pictures show distinct discrepancies between different materials eventually. All these works state that the polarization of an optical image is a potential way to make target detection and identification easier with higher accuracy.

Change Zeng, Qing Liu, Di Yang, Yonghong Zhan, Yaping Wang

Chapter 31. Analysis of Drift Adjustment by Space Optical Camera Platform

In order to reduce the image defect of TDI-CCD camera caused by drift angle, some causation and calculation methods of drift angle are analyzed, and some quantitative computational formula for the influence on image quality are also introduced, moreover the influence factors of drift angle and the image motion along and across the course are researched by simulation. Some phenomena appear on the actual flight experiment, that the yaw angle is instable when drift adjusting by satellite platform, which causes the drift angle error and then decreases the image quality. By analysis, it is discovered that the problem above is mainly caused by the response mechanism of satellite platform. That is, on account of design defect of satellite platform, it responds the drift angle which delivered by camera so slowly that the drift adjustment by platform lags behind the imaging. The analysis results contribute to the improvement on space optical camera platform, which are applied to the second generation satellite

Sanhai Ren, Xiang Fan, Fan Zhang, Zengli Su

Chapter 32. The Study on Retrieval Technique of Significant Wave Height Using Airborne GNSS-R

A marine environment remote sensing system based on multi-source and multi-destination GNSS-R technique is introduced in this paper. The system is independently developed and used in three airborne flight tests in specific area of Bohai Bay, Tianjin. A lot of effective GNSS-R signal data is collected, significant wave height under natural conditions is retrieved. The system receives the GNSS direct signal and reflected signal of the sea, then generate delay–doppler mapping (DDM) imagery by correlation process of the signal. Correlation power waveform of the DDM map is calculated using derivative of the correlation function (DCF), then significant wave height is calculated through DCF waveform width. The feasibility of this method is verified, it works under all-weather and all-day conditions with the advantages of high resolution and low cost, which has important significance for the monitoring of small and medium scale ocean state and physical phenomena.

Fei Xu, Xiechang Sun, Xinning Liu, Ruidong Li

Chapter 33. The Calibration Method of Channel Consistency of Distributed Digital Phased Array

In this paper, a new valid calibration method is put forward to satisfy the request of channel consistency of distributed digital phased array. Firstly, the time delay estimation algorithm based on temporal coherence is used to align the large time delay among channels. Then, the frequency domain equalization algorithm based on the least squares fitting is used to achieve consistency of magnitude and phase among channels. The effectiveness of above method is validated through analyzing of equalization result on MATLAB platform. The results shows that the magnitude and phase differences between reference channel and mismatch channel in the pass band are rescaled in the range of 0.015 dB and 0.1° respectively after the calibration of equalizer. Furthermore, this method has been applied in practical engineering project.

Na Wang, Xinshi Hu, Tian Yuan, Wentao Zhou

Chapter 34. Multi-hit Method for Weak Signal Detection of the Diffuse Reflection Laser Ranging in Daylight

Because of the strong background noise, the weak echo signal in diffuse reflection laser ranging is very difficult to detect in daylight, which limits the extensive application of diffuse reflection laser ranging. In this paper, the multi-hit method is proposed to solve the weak signal detection problem of diffuse reflection laser ranging in daylight. First of all, a fast performance prediction method for multi-hit Geiger-mode avalanche photodiode (GM-APD) is introduced. Then, taking the typical parameters of the diffuse reflection laser ranging system, the detection probability of the echo signal is analysed under different firing times. Furthermore, effective detection ratio is defined to evaluate the extraction cost of the echo signal. The theoretical analysis shows that processing only a few firings in one gate window can result in large increase of detection probability for diffuse reflection laser ranging in daylight. Meanwhile the optimization of the firing time for GM-APD can increase the effective detection ratio and reduce the extraction cost of the echo signal. Finally, the correctness of the theoretical analysis is verified by the system simulation. Therefore, the multi-hit method is one of the feasible ways to detect the weak echo signal of the diffuse reflection laser ranging in daylight.

Peng Zhao, Yan Zhang, Kunpeng Wang, Chenglin Wang

Information Science and Technology

Frontmatter

Chapter 35. A Real-Time Classification Algorithm for Multi-Velocity Measuring Data

This paper proposes a new real-time classification algorithm for multi-velocity measuring data under the response mode to improve the target trajectory stability. First, this paper analyses the defects of the existing method. Second, it designs a new classification algorithm which can classify the response data, the beacon data and the abnormal data. The key of the new algorithm is the selection of suitable classification references. The theoretical trajectory and the classified real measuring data at the historical moment are used as the classification references in different situations. Finally, validate the new algorithm with two kinds of typical real measuring data corresponding to two kinds of master stations configuration mode, the result shows that the algorithm can classify the three kinds of data correctly. On this basis, the real-time trajectory calculated is smooth and continuous and the data utilization is evidently increased. Therefore, the new classification algorithm of this paper is better than the existing method, which has guiding significance for improving the real-time data classification in different measuring systems.

Xiaohu Liang, Hua Zhao, Jiagui Huang

Chapter 36. New Algorithm for Guidance Instrument Error Separation

Environmental matrix S in the guidance instrument systematic error model is usually seriously ill-conditioned, which has a strong impact on the accuracy of the result of error separation. In this paper, new algorithm for guidance instrument error separation is presented. Based on some numerical iterative method, the new algorithm firstly converts the ill-conditioned algebraic equations to the corresponding stiff dynamic system, and stiff stable numerical method is applied to solve the stiff dynamic system. The convergence of the new method is proved. The method which used to solve the stiff dynamic system is given in the paper. Compared with the PB method (primary Bayesian), the numerical experiments illustrate that the new method is more effective for the Guidance Instrument Error separation.

Hua Zhao, Jiagui Huang, Xiaohu Liang, Yuming Hua

Chapter 37. Ionosphere’s Effect on the Demodulation BER Performance of a DS/FH-BPSK Signal

A phase-coherent direct sequence (DS) and frequency hopping (FH) spread-spectrum signal has a much wider bandwidth than simple DS spread spectrum signals. Due to the non-linearity of ionosphere and frequency hopping scheme of the signal, the binary phase shift keying (BPSK) bit error rate (BER) deteriorates. Under the assumption of purely-background ionosphere dispersion and a uniformly-distributed FH pattern, the BERs of both the pilot signal and the long-term signal in a specific DS/FH satellite link are acquired through using the mathematical tools concerning the probability density functions of random variables (RVs). Simulations under constant ionosphere dispersion and uniformly-distributed FH pattern scintillation conditions are carried out to verify the results of BERs.

Liyi He, Xiao Chen, Jinhai Sun, Junfu Chen

Chapter 38. De-noising Method Research on RF Signal by Combining Wavelet Transform and SVD

RF signal are widely used in many fields such as aerospace measurement and control field for its space distance transmission characteristics. However, noise and interference would be brought in through space magnetic field, channels, equipment components and so on, which would affect spread, analysis and processing of RF signal. There are little research about RF signal de-noising at present. Traditional filter de-noising method, wavelet threshold method and SVD method were studied comparatively in RF signal. Simulation results and extraction effects of useful RF signal were analyzed by different methods. The effection of noise suppression was realized by those three methods above, but they all had shortcomings. Filter method decreased signal energy significantly, wavelet transform method was easy to lead to the distortion of reconstruction signal, and SVD method needed longer operation time. For those disadvantages, method of combining wavelet threshold and SVD was put forward to reduce the noise. And by this way, it improved the operation efficiency, and the effectiveness and superiority of noise suppression were verified by de-noising performance metrics.

Junyao Li, Yongbin Li, Xiaoqiang Wang, Peijie Zhang

Chapter 39. The Multi-Objective Routing Optimization Algorithm for Hybrid SDN

In order to make full use of advantages of SDN nodes to optimize network performance, traffic engineering of hybrid SDN becomes a current research focus, and routing optimization is one of the key strategies to realize the goal of traffic engineering. However, current traffic engineering of hybrid SDN fails to take overall load balancing of the network and processing capacity of SDN nodes into consideration. To solve the above problem, a multi-objective routing optimization algorithm, i.e. MCS, is proposed to optimize link utilization and transmission delay of SONet under the actual restriction of SDN-FE. Experiments show that in light network load, MCS is similar to SOTE in performance, but the former could reduce 9% of network compared with the latter in heavy load. Therefore, MCS is able to provide better optimization.

Suolin Gu, Lijuan Luo, Zhekun Zhao, Xiaofang Li

Chapter 40. Parameterized Unified Modulation Model Design for Satellite Communications

The development of real-time handover and multi-modulation systems is a key issue for meeting the challenges of multiple users, variable access, and highly diversified modulation schemes in satellite communications. In this study, a novel parameterised sub-component decomposition and state-mapping-based unified modulation model is accordingly developed. The model linearly expresses the arbitrary modulated signal through sub-component decomposition and constructs a time-homogeneous Markovian mapping state set on the basis of the projection coefficients. Monte Carlo simulations demonstrate that, with seven sub-components, our model can uniformly generate modulated signals which are virtually identical with the conventional ones. With the features of structural efficiency, signal expression flexibility, and mapping-rule consistency, our model represents a feasible contribution to next-generation satellite communication systems.

Yabo Yuan, Bo Wang, Bin Wu

Chapter 41. Study on the Influencing Factors of Frequency Locked Loop Based on Stochastic Resonance

This paper proposes a study with signal to noise ratio (SNR), sampling frequency and system parameters because of the no-clear influence factors of the frequency locked loop (FLL) based on stochastic resonance (SR). Firstly, basic principle of FLL based on SR is simply interpreted and a simulation platform is set up. Secondly, through changing signal to noise ratio and sampling frequency and system parameters, the influence that they brings out is gradually clear. Finally, some meaningful conclusions are carried out. The tracking performance gets poor with the SNR declining, and the limit of SNR is E b /N0 = 1 dB. The sampling frequency must be set 50 times higher than the frequency of signal, and the changing of sampling frequency has little effect on the improvement of tracking performance. System parameters are the critical factors that influencing the performance of FLL based on stochastic resonance, and it presents as an alternative numerical interval. The three key factors must be deliberated before designing and using the FLL based on SR.

Weitong Zhang, Zhiqiang Li, Huan Chen, Shengchao Shi

Chapter 42. Frequency Stabilization of an Optoelectronic Oscillator Based on Phase-Locked-Loop

In this paper, frequency stabilization of an X-band optoelectronic oscillator (OEO) is obtained by phase locking to an oven-controlled crystal oscillator (OCXO) through a fractional phase-locked loop (PLL). The relationship between the loop transfer characteristic of PLL and the phase noise of the oscillation is analyzed. The overall phase noise performance of the OEO is improved with the self-injection-locking (SIL) approach, where the phase noise of the OEO is suppressed for over 20 dB within frequency offsets from 10 Hz to 10 kHz. The phase noise of the PLL-locked SIL OEO is −55 dBc/Hz at 10 Hz offset and −124 dBc/Hz at 10 kHz offset and the frequency overlapping Allan deviation (ADEV) reaches 1.14 × 10−11 at average time of 100 s, proves the high frequency stability of the obtained output.

Rongrong Fu, Yanhong Zhu, Xiaofeng Jin

Chapter 43. The Techniques of Network Coding Applied in the Physical-Layer of the Wireless Communication Systems: A Survey

Based on the study of the principles and the development of the network coding, the survey analyzes its applicable techniques in the physical-layer of the wireless communication systems and focuses on the physical-layer network coding (PNC) and the joint design of the channel coding and the network coding techniques. On one hand, the survey firstly introduces the mechanism of the PNC and then summarizes the current results and the future directions of the following classified hot topics: the coding and decoding design, the synchronization problem, the combination with other transmission techniques, the PNC capacity and the application scenario extensions of the PNC. On the other hand, the survey reviews on the joint design techniques of the channel coding and the network coding in accordance with different starting points which are inducted as basing on the type of the channel coding, modifying the mode of handling the soft information, utilizing of the PNC and considering various system scenarios.

Xiaoting Wang, Qiang Mei, Xu Yao

Chapter 44. Research on the Improvement of LTP Protocol in Space DTN Network Based on Network Coding

With the development of the space communication application, it is more and more important for the space Delay Tolerant Networks (DTN) nodes to communicate with each other. In order to provide the reliable data transmission in space DTN network, the article firstly introduce the characteristics of the space DTN network and its protocol stacks, especially the designs and procedures of the Licklider Transmission Protocol (LTP). Then, with the detail analysis of the shortcomings of LTP protocol, we suggest an improvement of LTP protocol in Space DTN network based on Network Coding (NC-LTP), and make efforts in the theoretical works and simulation of such new approach. The theoretical and simulation results show that, compared with the traditional LTP protocol, NC-LTP performs well in the different situations, such as time-delay and packets loss rate, which is suitable to be used in the space DTN network environment with the characteristics of high dynamic, high bit-error rate and band-width limited.

Peng Wan, Shijie Song, Zhongjie Hua, Shengli Zhang

Chapter 45. Research on Security Protection of the Communication Network for Space TT&C Based on TCP/IP Protocol Vulnerabilities

Since the completion of the communication network for Space TT&C (Tracking, Telemetry and Command), the whole operation is stable. However some problems have also been exposed in network security. In this paper, in order to study and solve the network security problems in the current communication network for Space TT&C, based on the analysis of the basic principle of the TCP/IP (Transmission Control Protocol/Internet Protocol) layered protocol, the protocol vulnerabilities and common attack methods of the IP network data link layer, network layer and transport layer are studied in detail, the network security deployment of current communication network for Space TT&C is Introduced. According to the current situation of network, the security problems of the data link layer, network layer and transport layer of the communication network for Space TT&C are analyzed. With all kinds of security problems which have been analyzed, the effective defense measures and protection methods are given. Finally, the design scheme of a set of configuration and maintenance management system for the communication network for Space TT&C is discussed. The effective management of the safe and stable operation of the communication network for space TT&C is realized by the establishment of equipment configuration database, information record database and network fault database.

Shuai Yuan, Peng Liu, En Zhao

Chapter 46. Timeliness Analysis and Countermeasure of Remote Control of Equipment Monitoring and Control System

With the development of communication technology and computer network technology, satellite ground stations have varying degrees of construction equipment monitoring system, can manage distribution in different regions of the multi satellite ground station, realized the control equipment unattended, remote monitoring, equipment reliability and stability control were greatly improved. But with the continuous expansion of the application system, the use of increasingly strong demand, the frequency of large task, task closely spaced more and more, the satellite ground station equipment monitoring and control system of timeliness problems continue to appear, the main performance of equipment with a longer time in the satellite earth station, efficiency is not high, in the task of preparing the occupation in large proportion when in use, which restricts the application efficiency of satellite system. This paper analyzes the influence factors restricting the effectiveness of control equipment monitoring system, puts forward the measures and Countermeasures in the future construction of the system, can learn from these methods and apply them, continuously improve the equipment control efficiency.

Jianglai Xu, Lei Wang, Hui Zhang

Chapter 47. Designed on Operation and Management System for Aerospace TT&C Station

According to the status quo of TT&C equipment, communication equipment, meteorological equipment, service support equipment vertical management, node management dispersed, and the running status cannot be real-time acquired within the TT&C station domain, the TT&C station operation management system is designed and developed, including the TT&C Equipment Protocol Conversion Software, the Meteorological Operation Management Software, the Service Operation Management Software, the TT&C Information Check and Test Software, the Comprehensive Information Management Software and the Integrated Status Revelation Software, realized the hierarchical management model of the running status acquisition, data processing, information display and fault alarming of four professional domain equipment in TT&C station management domain, established the standardized TT&C station management system, standardized the tracking process of TT&C station, realized the whole process management from mission starting, equipment calibration, tracking and capturing to the analysis of data quality, improved the TT&C station management quality and the automation operation efficiency.

Qi Dang, Weiping Li, Dong Guo, Shuncheng Ning, Xiaopeng Wang
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