CAJ | 학술논문

快速分级后向投影算法(Fast Factorized Back-Projection Algorithm, FFBPA)研究了 BPA 中的冗余计算，通过子孔径划分，在极坐标系下将信号逐级相干积累成像，该方法避免了BPA中每个图像点的重复性全孔径搜索过程，大幅减少了计算量。然而多级插值操作加剧了误差积累，减少分级次数又影响算法效率。为解决这一矛盾，该文结合极坐标格式算法(PFA)提出了一种新的多级迭代快速 BP 成像算法，并将算法拓展应用到曲线轨道，多模式SAR中。分析表明，该文方法与FFBPA相比更高效。最后通过该文算法与FFBPA的星载0.1 m超高分辨率聚束SAR成像进行仿真实验对比，验证了该方法的优越性。
쾌속분급후향투영산법(Fast Factorized Back-Projection Algorithm, FFBPA)연구료 BPA 중적용여계산，통과자공경화분，재겁좌표계하장신호축급상간적루성상，해방법피면료BPA중매개도상점적중복성전공경수색과정，대폭감소료계산량。연이다급삽치조작가극료오차적루，감소분급차수우영향산법효솔。위해결저일모순，해문결합겁좌표격식산법(PFA)제출료일충신적다급질대쾌속 BP 성상산법，병장산법탁전응용도곡선궤도，다모식SAR중。분석표명，해문방법여FFBPA상비경고효。최후통과해문산법여FFBPA적성재0.1 m초고분변솔취속SAR성상진행방진실험대비，험증료해방법적우월성。
The redundant calculation in Back-Projection Algorithm (BPA) is studied in Fast Factorized BPA (FFBPA). By dividing sub-apertures and accumulating signal coherently in polar format coordinate, image with high resolution is obtained. The progress of repeatedly searching every signal in full aperture for every pixel is avoided in FFBPA, thus the amount of computation is reduced. However, multi-stage interpolation operation increases the error accumulation. Combining with the original Polar Format Algorithm (PFA), a new multi-stage iteration Fast PFA is proposed, and it is modified to process data in curve orbit and multiple modes SAR. Analysis indicates that the proposed algorithm is more efficient than FFBPA in practice. Comparison of simulation results of spaceborne spotlight SAR with very high resolution (0.1 m) processed by the proposed algorithm and FFBPA verifies the superiority of the new algorithm over FFBPA.