R-D域对比度最小化解SAR Doppler模糊

为了准确估计合成孔径雷达(syn thetic apertureradar,SAR)高质量成像所必需的D opp ler中心,提出了一种解SAR D opp ler中心模糊的方法。利用SAR所固有的距离徙动(range m igration,RM)现象的性质,通过搜索使距离D opp ler域(range-D opp ler,R-D)信号强度对比度最小的D opp ler中心模糊数,就能实现解模糊。分析了该方法的性能。实验结果表明:与传统的SAR D opp ler中心解模糊方法相比,该方法既适用于城区高对比度场景,也适用于山地低对比度场景,并且由于无需做耗时的相关或快速Fourier变换运算以及只需部分距离单元参与运算,具有较高的计算效率。

PRF-Ambiguity resolution for SAR by contrast minimization in the range-Doppler domain

An algorithm was developed to accurately estimate the Doppler centroid which is needed for high quality synthetic aperture radar(SAR) image formation by resolving the SAR pulse repetition frequency(PRF) ambiguity.The algorithm uses the SAR range migration to resolve the PRF ambiguity by searching for a PRF-ambiguity number that minimizes the intensity contrast in the range-Doppler domain.Experimental results show that the approach,compared to traditional methods for resolving the SAR PRF ambiguity,is more suitable for both high contrast scenes such as urban areas and low contrast scenes such as mountains and is more computationally efficient since there are no time-consuming correlations or FFT operations needed in the range-Doppler domain and only parts of range cells are used in the calculation.