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Über dieses Buch

Spacecraft TT&C and Information Transmission Theory and Technologies introduces the basic theory of spacecraft TT&C (telemetry, track and command) and information transmission. Combining TT&C and information transmission, the book presents several technologies for continuous wave radar including measurements for range, range rate and angle, analog and digital information transmissions, telecommand, telemetry, remote sensing and spread spectrum TT&C. For special problems occurred in the channels for TT&C and information transmission, the book represents radio propagation features and its impact on orbit measurement accuracy, and the effects caused by rain attenuation, atmospheric attenuation and multi-path effect, and polarization composition technology. This book can benefit researchers and engineers in the field of spacecraft TT&C and communication systems.

Liu Jiaxing is a professor at The 10th Institute of China Electronics Technology Group Corporation.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
This book attempts to present the tracking, telemetry, and command (TT&C) of flight vehicles such as air vehicles (less than 20 km in altitude), near-space vehicles (20–100 km in altitude), and spacecrafts (greater than 100 km in altitude). Those flying at an altitude of more than 2 × 106 km are also known as deep-space vehicles. Specifically, the flight vehicles include missiles, satellites, spaceships, space stations, deep-space probes, near-space vehicles, UAVs, airships, or balloons, all of which are subject to TT&C. For TT&C and communication (C&T) systems, there are radio, optical, infrared, and other types. Among them, the radio continuous-wave C&T system is the most widely used one, which is mainly described in this book.
Jiaxing Liu

Chapter 2. Theories and Technologies of Tracking and Orbit-Measuring

Abstract
Tracking and orbit-measuring refers to tracking and measuring the flight trajectory of a flight vehicle by using measurement elements such as range, velocity, angle, and altitude measured by the measuring stations. “Trajectory” is a general term. The unpowered flight trajectory of spacecraft-like satellites refers to orbit, which follows the orbital dynamics. The powered flight trajectory of missiles and rockets refers to ballistic trajectory; the flight trajectory of aircrafts generally refers to track. Trajectory and track both follow the aerodynamics. Thus, orbit-measuring as discussed in this book refers to orbit measurement of spacecraft, trajectory measurement of missiles, and track measurement of aircrafts.
Jiaxing Liu

Chapter 3. Information Transmission Technologies

Abstract
Distortion and noise are two major subjects in information transmission research. Essential requirements for a transmission system are low distortion caused by signal transmission and low additional noise as much as possible, which are the major measurement factors for channel performance.
Jiaxing Liu

Chapter 4. Spread Spectrum TT&C

Abstract
Spread spectrum is an information transmission technology. The spread spectrum TT&C system is a system which realizes TT&C and information transmission using direct sequence (DS) spread spectrum, frequency hopping (FH) spread spectrum, time hopping (TH) spread spectrum or any combination of them. PN codes are the typical spread spectrum signals. For example, PN codes in a DS TT&C system are used for spread spectrum of telemetry & telecommand information and for integration of ranging signals and information. With respect to the orbit-measuring function, the system also uses PN codes for ranging and carriers for Doppler velocity-measuring, and then conducts angle tracking for the carrier signals after spread spectrum by PN codes.
Jiaxing Liu

Chapter 5. Special Issues on Radio Transmission Channel in C&T

Abstract
The channel referred to in this chapter is the medium for information transmission. Radio transmission channel refers to the channel transmitting electromagnetic signals in free space (in a broad sense, it may include related components and links). Radio transmission channel may bring in many adverse impacts on C&T signals, such as orbit-determining error and signal attenuation caused by radio wave transmission characteristics, multipath interference caused by reflected wave, various types of noise and interference introduced by the channel, large Doppler frequency shift in high-dynamic radio channel, and the non-real time caused by the channel with time delay. The impacts of the last three transmission characteristics have been addressed in the early chapters.
Jiaxing Liu
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