Resarch On The Range-Doppler Compensation Algorithm For Weak Target Detection

With the development of stealth technology, radar weak signal detection hasbecome one of the current hot and difficult problems in the field of Early-warningradar detection. At present, we adopts the technology of Long-time pulse integrationfor radar signal processing which can effectively improve the signal to noise ratio(SNR) of detecting stealth targets by accumulating more energy with more time cost.However, with the increase of time, the range migration, Doppler frequencymigration and even echo beam migration may occur during the pulse integrationperiod.On the basis of analysis of these echoes walk, a weak target detection algorithmon the compensation algorithm of the Range-Doppler is proposed. The main researchworks of this thesis are presented as follows:(1) We study the principle of radar weak target pulse of a long period oftime and analyze two kinds of pulse accumulation. Then acompensation algorithm based on the keystone transform is proposedfor the range migration of the constant velocity target and the threeimplementation approaches are discussed from the proposedalgorithm.(2) For the problem of range migration and Doppler frequency migrationin the maneuvering weak target detection, a weak target detectionimproved algorithm on the compensation algorithm of the Range-Doppler is proposed. In this method, Keystone transform is used tocorrect the range migration, and FRFT is used for phase compensation.Simulation results show that this improved algorithm can improve theperformance of weak maneuvering target detection.(3) For the problem of edges of clutter background, the ability oftraditional CFAR algorithm which suppresses the target shieldingwould decline. To solve this problem, an ordered statistics CFARalgorithm based on Switching (S-CFAR) is proposed. We select theappropriate cell according to the information from the detection celland estimate the background noise. Simulation experiments show that it can suppress the clutter edge of the shadowing effect and have agood performance under uniform and non-uniform background. Also,the complexity of calculation can be saved.