基于多特显点综合的SAR／ISAR自聚焦

利用积累（相干或非相干）提高信杂噪比的概念，并考虑实际存在的问题，对基于多特显点的自聚焦原理进行了综合研究，进而对现在应用较多的两种方法做了比较，并对PGA法进行了改进。

The SAR/ISAR autofocus based on the multiple dominant scatterers synthesis

Many SAR/ISAR autofocus methods have been presented and are successfully used in reality, some of which are based on the multiple dominant scatterers synthesis. They synthesize multiple scatterers to increase the signal to clutter and noise ratio (SCNR), consequently increasing the precision of the estimation of he initial phase error. The comparison between the methods has been made in a lot of literature. But they only compare the results of computer simulation or real data. Based on the concept of coherent/incoherent accumulation to increase the SCNR and considering the existing problems, we discuss the SAR/ISAR autofocus methods based on the multiple dominant scatterer synthesis and compare the performance of these methods. Finally, an improved PGA algorithm is presented.