ISAR運(yùn)動參數(shù)估計(jì)和補(bǔ)償改進(jìn)方法

在使用FFT距離多普勒算法進(jìn)行ISAR成像處理時，回波相關(guān)性的減弱將加大運(yùn)動補(bǔ)償難度，帶來較大的誤差。該文在常規(guī)相鄰相關(guān)法基礎(chǔ)上，提出了一種改進(jìn)的運(yùn)動補(bǔ)償方法。在距離向上，利用基準(zhǔn)回波相關(guān)法與曲線擬合，克服了低回波相關(guān)性下包絡(luò)對齊時出現(xiàn)的包絡(luò)漂移、包絡(luò)跳變等缺陷；在方位向上，利用DCFT變換，對目標(biāo)的運(yùn)動參數(shù)進(jìn)行精確估計(jì)并加以補(bǔ)償，減小了回波相關(guān)性降低對相位補(bǔ)償?shù)挠绊憽?a target='_blank' class='arckwlink_none'>仿真驗(yàn)證了該方法的有效性。
關(guān) 鍵 詞 離散調(diào)頻傅里葉變換; 包絡(luò)漂移; 包絡(luò)跳變; 二次曲線擬合

Abstract When the range-Doppler algorithm is used in inverse synthetic aperture radar (ISAR) imaging, the reduction of echo correlation will add more difficulties on motion compensation and bring more error. Accordingly, based on the adjacent-correlate compensate method used in FFT range-Doppler algorithm, an improved compensation method is presented in this paper. The traditional compensation method is modified to avoid the envelope drift and envelope jump in range align. In phase compensation, a new algorithm based on accurate target parameter estimation by use of discrete chirp-Fourier transform (DCFT) transform is presented. Finally the improve method is verified by simulation.
Key words discrete chirp-Fourier transform; envelope drift; envelope jump; 2 order polynomial fitting