| The research of this thesis is a part of the key project of national high tech research and development project (863 project) - the application system for airborne weather radar detection of clouds and rain. Because of the high flexibility of airborne platform, the 3-D real-time observation of weather systems can be realized in a close range and high precision. Due to the influences of many factors (e.g. airflow, flight operation), it is impossible to keep the airborne platform under uniform motion and steady flight attitude. Consequently, the variation of flight motion and attitude will affect the transmitting and receiving of the radar detecting wave beam, and then weaken the detecting veracity. As a result, it is necessary to adopt motion compensation to improve the reliability of high-resolution detection of airborne radar. Among the domestic and abroad research publications, there are not any reports on theoretic researches of motion compensation algorithms for airborne weather radar detecting system. Therefore, the research results of this thesis not only have substantial practical application value, but also fill the theory-gap in this domain and enhance independent intellectual property capabilities of this country.The following contents are discussed in this thesis.(1) The theoretic analyses of the influences of motion error on the detection effect of airborne weather radar. Based on the detection theory of Doppler weather radar, the processing method of radar signal and the acquirement of raw data, analysis and demonstrate the theoretic causes of the influences of carrier aircraft motion error on the Doppler weather radar observation data. Classify the motion errors into flight attitude variation error and velocity variation error according to the different influences causes discussed above.(2) The measurement, acquirement and precision test of the carrier aircraft motion state data. Research and validate the rationality and feasibility of using real time flight velocity, elevation angle, yaw angle and roll angle to describe the carrier aircraft motion state. Analysis the rationality and feasibility of using GPS/INS combined observing system to detect and provide the four parameters of the carrier aircraft motion state。The observation data from one double GPS/INS attitude and orientation system is analyzed, tested and compared with the data of one famous high precision observation system, the results demonstrate that the proposed navigation-used motion state observation system could be used to provide the parameters of the carrier aircraft motion state with high precision.(3) Theoretic research of the motion competition algorithm for the flight attitude variation error. Analysis the different coordinates of carrier aircraft, loaded weather radar and the motion state observation system separately and the transition relationship between different coordinates, proposed the compensation algorithm for flight attitude variation error by continued transacting form motion state observation data coordinates to carrier aircraft coordinates then to antenna coordinates and to Geodetic coordinates finally. Validate the rationality and feasibility of the proposed algorithm by applying it in an ideal case. For the proposed algorithm module only depends on the motion state observation data, it can be implanted either in the prepositive module of signal processing system as the antenna platform stable servo or in the postpositive module to process observed data directly when the mechanical servo breaking down. Consequently, the observation data is improved in precision, reliability and stabilization.(4) Theoretic research and simulation validation of the motion competition algorithm for the velocity variation error. Proposed the compensation algorithm for velocity variation error by decompounding the carrier aircraft velocity into the component along radial and the component perpendicular to radial and compensating for the two components respectively. Develop the simulation system of the airborne weather radar system on the MATLAB/SIMULATION platform and implants the proposed algorithm module of velocity variation compensation in the simulation system. Take a comparative test of the observation data of a X band phase array rain radar and the compensation data of the simulation system, the results validate the rationality and feasibility of the application of the proposed algorithm in X band phase array rain radar observation data. Take an ideal test of the W band cloud radar simulation system, the results validate the rationality and feasibility of the application of the proposed algorithm in the W band cloud radar observation data.The research results of this thesis show innovations in several aspects.(1) The results make up the theory-lack of motion compensation algorithms for airborne Doppler weather radar detecting system in our country, and has guiding significance for the following researches.(2) Base on these compensation algorithms, one innovative method of the motion compensation for airborne Doppler weather radar, which uses software, has been invented. It makes up the limitation of the motion compensation method which uses hardware.(3) Adopt the double GPS/INS attitude and orientation navigation system observation data which is used for navigation before in the motion compensation for airborne Doppler weather radar, makes up the limitation of the traditional unitary observation system with inertia gyroscope and greatly improves the observation precision of the motion error.(4) The simulation system of airborne weather radar is developed on the MATLAB/SIMMULATION platform. Furthermore, the motion compensation algorithm module is implanted into this system and validated without field experiment.
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