The SAR/ISAR autofocus based on the multiple dominant scatterers synthesis
HUANG Yuan bao,ZHENG Yi ming,BAO Zheng(National Key Lab. of Radar Signal Processing, Xidian Univ., Xi′an 710071, China)
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.