States Determination For Double Satellites Formation Constellation With GPS And 'GPS-like' Ranging Technology

Double-Satellite Formation Constellation plays an important part in current research, the realization of whose function depends on the precise formation states determination, which include absolute and relative attitudes, positions and clock biases separately.GPS is a chief means to the states determination of formation constellation, and it has two detemination modes: One is pseudorange measurement, which uses GPS pseudorange data, and the accuracy of which is m. The other is carrier phase measurement, which use GPS carrier phase data, and the accuracy of which is 10^-3m. The former is mainly used to determine position and it is simple and convenient, but the accuracy of measured position is too poor; The latter can be used to determine both position and attitude with high accuracy, but is complicate to compute, especially is hard to initialize the single differential GPS inter-satellite integer ambiguity quickly. In addition, it may not get sufficient accurate states in some applications that are strict with formation states.'GPS-like'Ranging technology is introduced to improve the accuracies of measured states, which use onboard satellite transceivers to transmit and receive some special signals, which are similar to GPS pseudorange and carrier-phase signals, but with higher accuracies that are owed to shorter pseudo-code length and wavelength of carrier phase. However, only using this technology cannot determine absolute states, and it adds'GPS-like'integer ambiguity problem. The emphasis of this dissertation is combining GPS and'GPS-like'Ranging technology to accurately determine absolute attitudes, relative position and relative clock bias of Double-Satellite Formation Constellation. Firstly it introduces coordinate systems and antenna measure systems in use. Secondly, it describes the background knowledge of GPS and'GPS-like'technology separately, which both include definition and composition, basic principle, relevant observation equations and their linearization forms. Thirdly, two states determination mathematical models have been built. Model I combines two observation data, including single differential GPS inter-satellite carrier phase data and'GPS-like'pseudorange data. Model II combines three observation data, which adds single differential'GPS-like'intra-satellite carrier phase data comparing to Model I. The initialization problems of single differential GPS inter-satellite integer ambiguity and single differential'GPS-like'intra-satellite integer ambiguity...