| The high-altitude and high-speed platform radar mainly includes space based radar(SBR) and aerospace aircraft airborne radar. The aerospace aircraft airborne radar ofnear space platform is a typical high-altitude and high-speed platform radar and it has awide range of detection, long warning time, strong defensive force, etc. These featuresplay an important role in early warning, resource exploration and information gathering.So the research of aerospace aircraft airborne radar of near space platform is of greatsignificance.Due to the features of the platform, the echo of near space platform radar generallyexist problems of range/Doppler ambiguity and migration through resolution cell(MTRC). These phenomena have a negative impact on air moving target detection.Based on the technology of detecting moving target in aerospace aircraft airborne radarof near space platform, the main content of this dissertation is organized as follows:1. The characteristics of clutter of near space platform radar are analyzed. Based onthe geometric model of radar, the space-time clutter model is established, and also the2-D power spectrum of clutter of near space platform radar is simulated.2. According to the range and Doppler ambiguity of the near space platform radarclutter, the waveform design and deconvolution algorithms for it are proposed. On onehand, the approach based on orthogonal waveform for range ambiguity is studied, themethod based on different PRFs (pulse repetition frequencies) and OFDM (OrthogonalFrequency Division Multiplexing) signal for Doppler ambiguity is discussed.Meanwhile, according to OFDM signal for the Doppler ambiguity, the impact on thedifferent interpolation methods is analyzed. On the other hand, based on the near spaceplatform radar, the mathematical model of the process of range/Doppler ambiguity isestablished. Then, the deconvolution algorithms for range/Doppler ambiguity areproposed. It is shown by the result that the higher the degree of ambiguity is, the lessproportion of the information will lose during the algorithms and the better theperformance will be.3. According to the MTRC (migration through resolution cell) of clutter of the near space platform radar, the method based on keystone transform and deconvolution ofrange walk correction is developed. Meanwhile, the evaluation and computation ofkeystone transforms using different interpolations methods are analyzed. It is shown bythe results that the truncated Sinc function interpolation, frequency samplinginterpolation and Lagrange interpolation method has a better performance in achievingkeystone transforms.4. Based on the previous work, the STAP detection methods are developed. Thedetection of STAP moving target detection of near space platform radar is studied. It isshown that the use of the method in the previous work of STAP detection has improvedthe performance of the STAP. |
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