| In the nonhomogeneous environments, the performance of space time adaptive processing (STAP) proposed by Brennan often declines sharply due to the fact that it is lack of independent identically distributed train samples. Thus, the new STAP method that can adapt to the real nonhomogeneous environments is becoming one of the main research directions of the current STAP techniques. This paper put its emphasis on the investigation of the algorithm of clutter suppressing and moving target detecting for phased array airborne radar in nonhomogeneous environment. The solutions to the nonhomogeneity about power fluctuation, interfering target and isolated interference were studied from chapter 2 to 6, the ones about range dependence of non-sidelooking array were investigated from chapter 7 to 8.1. In chapter 2, the research was focused on auxiliary channel processing (ACP) STAP Firstly, the unified rule how to select auxiliary channels was given, which can overcome the drawback the conventional ACP can't be used in non-sidelooking array, thus is the reduced dimension method with adaptive configuration, however the conventional ACP is that with fixed configuration. Latterly, a new ACP to resist interfering target was proposed, that is, under the condition of samples being limited, the target self-canceling is resulted in the conventional ACP because the target from main channel leak to auxiliary channel, however, the new ACP has not this phenomenon because the target in main channel is also filtered, thus can adapt to the nonhomogeneous environment of the samples being limited.2. In chapter 3, a new STAP method to suppress clutter and interferer in non-homogeneous environment combined direct data domain (DDD) with statistic STAP was proposed firstly, which can effectively compensate the performance loss incurred by the spatial and temporal aperture loss of the DDD approach. An error correction technique by correcting radar receive data with real steer vectors was put forward latterly, which can guarantee the predeterminative condition of DDD algorithm that the array is uniform. A new method of target signal filter was given lastly, which can be used in real phased array airborne radar system.3. In chapter 4, a new method of two stage hybrid space time adaptive based on non-homogeneous environment was presented, in which the homogeneous clutter is firstly suppressed based on auxiliary channel processing (ACP) approach by selecting auxiliary channel according to clutter's distributing characters in the beamDoppler space and the isolated interferers is latterly mitigated based on direct data domain algorithm. This method can overcome the drawback of the method Adve proposed that is tampering with each other between the clutter and the isolated interferer, has advantages of excellent target detection performance, good robust to whether small yaw exists or not, and low computation load.4. In chapter 5, a new method to suppress strong isolated interferers was put forward, in which two solutions were given. The strong isolated interferers are mitigated firstly by oblique projection, and the processed cells are also used as train samples of adaptive clutter suppression's weight when the train samples is lacking. The cells with strong isolated interferers are directly detected after the interferers and clutter are both suppressed by using null technique, and the processed cells are no longer used as train samples when the train samples is abundant. Unlike DDD algorithm, the proposed methods needn't to compute the inversion of the covariance matrix for every cell, and have low computational complexity.5. In chapter 6, a new method to moving target detection in nonhomogeneous environment based on maximum likelihood was presented, in which, the autoregressive model is used to whiten the data radar received in time domain firstly, the maximum likelihood method is used to estimate the target return amplitude in every cell latterly, and the target detection is handled by comparison of the estimated result...
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