Doppler Parameter Estimation And Sar Wave Number Domain Algorithm Research

SAR is developed after World War II. It has important value in military and civil. Conventional algorithms for synthetic aperture radar uses the matched filter and convolves the data with a reference phase signal which changes with range. Its frequency domain implementation is cumbersome. This effects the quality of SAR image.ω? k is a precise algorithm , the quality and resolution of SAR image can be improved in this way.This dissertation discusses the estimating of Doppler parameter, andω? k. AS follow:1.Two solutions of estimating the Doppler centroid are put forward. We processe the Doppler centroid estimation in the frequency domain and time domain. Also this Chapter discusses principle of the Doppler centroid estimation.2.Two kinds of autofocus algorithms are presented in Chapter 4, Map-Drift (MD) and Phase Gradient Autofocus(PGA). Operand of Map-Drift is large, so 2 ways of reducing the operand are put forward, which are increasing the iterative step and decreasing the numbers of range cells. At last I apply PGA and MD to real SAR data ,and get the desirable image.3.ω? k algorithm is discussed, and compared with RD algorithm. From the simulation and the real imaging result, Sinceω? k method FFT the echo signal, and transform it to theω? k domain, it is the most effective method to implement the 2-D SAR shifting filter. However, STOLT interpolation will increase the imaging time, and will influence the quality of the image.