Research And Implementation On Sidelobe Cancellation And Clutter Suppression Of Radar

Generally, Radar echoes contain target, clutter, interference and receiver-noise signal. The clutter and the interference signals are much stronger than the target signal, which would seriously affect the normal operation of the radar. An important part of radar signal processing is that extract the target signal from the complex radar echoes.Sidelobe cancellation technique can effectively counteract sidelobe jamming. The open-loop adaptive sidelobe cancellation technique is based on the minimum mean square error criterion to calculate the optimal weights, and then apply the optimal weights to sidelobe canceling system. The system can automatically correct the weights according to the change of the input signal. The adaptive sidelobe canceling technique has a good effect on the anti-jamming in theoretical analysis, but in practice it does not work very well. In this paper, the factors that affect the performance of sidelobe cancellation and the attentions that need to consider in engineering practice will be discussed.Moving target indication(MTI) and Moving target detection(MTD) are the major techniques of clutter suppression, and they are all based on the different spectrum between target signal and clutter signal. Both of the techniques use the filter to eliminate clutter, and extract the target signal information. Owing to the period of MTI filter, the blind speed target also would be eliminated, thus leads to the pulse repetition frequency staggering to solve this problem and meet the requirements of engineering. For weather, chaff jamming and other moving clutter, the adaptive moving target indication(AMTI) can implement the moving clutter suppression. The important part of AMTI is to estimate the center Doppler frequency of clutter spectrum, this paper puts forward to using centroid method to estimate the Doppler frequency accurately. The design of clutter suppression filter is the core of the MTI, This paper presents an optimal design of MTI filter.This paper describes the basic principles of the radar signal processing systems based on the data stream. Using the thought of data stream, the radar system relies on the data flow driven rather than an unified timing control, which is one direction of radar signalprocessing system. For hardware platforms and implement of sidelobe cancellation and the clutter suppression is discussed. In sidelobe cancellation section, the implement of DSP and the simulation of the test data are introduced in detail. In clutter suppression section, the functions of the clutter suppression are discussed in detail, and giving some true pictures of radar terminal. The main problems encountered and solutions are discussed in detail.