TY - JOUR
T1 - Highly squint SAR data focusing based on keystone transform and azimuth extended nonlinear chirp scaling
AU - Sun, Zhichao
AU - Wu, Junjie
AU - Li, Zhongyu
AU - Huang, Yulin
AU - Yang, Jianyu
PY - 2015/1
Y1 - 2015/1
N2 - Highly squint synthetic aperture radar (SAR) data focusing is a more challenging and difficult task than the side-looking SAR due to the strong 2-D coupling of echo signal induced by the imaging mode. Although several algorithms have been proposed, they fail to take into consideration the spatial variance of linear range cell migration (RCM). Moreover, the RCM correction (RCMC) process in range frequency and azimuth time domain by phase multiplication brings the problem of azimuth variation of the Doppler centroid, which has a great influence on the azimuth focusing. In this letter, an algorithm based on keystone transform (KT) and azimuth extended nonlinear chirp scaling (ENLCS) is derived to deal with these problems. A new method for higher order RCMC is derived to remove the residual RCM after KT. Then, azimuth ENLCS is performed to equalize the azimuth-variant Doppler centroid and FM rate. The simulation results verify the effectiveness of this algorithm.
AB - Highly squint synthetic aperture radar (SAR) data focusing is a more challenging and difficult task than the side-looking SAR due to the strong 2-D coupling of echo signal induced by the imaging mode. Although several algorithms have been proposed, they fail to take into consideration the spatial variance of linear range cell migration (RCM). Moreover, the RCM correction (RCMC) process in range frequency and azimuth time domain by phase multiplication brings the problem of azimuth variation of the Doppler centroid, which has a great influence on the azimuth focusing. In this letter, an algorithm based on keystone transform (KT) and azimuth extended nonlinear chirp scaling (ENLCS) is derived to deal with these problems. A new method for higher order RCMC is derived to remove the residual RCM after KT. Then, azimuth ENLCS is performed to equalize the azimuth-variant Doppler centroid and FM rate. The simulation results verify the effectiveness of this algorithm.
KW - 2-D spatial variation
KW - Extended nonlinear chirp scaling (ENLCS)
KW - highly squint synthetic aperture radar (SAR)
KW - keystone transform (KT)
UR - https://www.scopus.com/pages/publications/84906782614
U2 - 10.1109/LGRS.2014.2329554
DO - 10.1109/LGRS.2014.2329554
M3 - 文章
AN - SCOPUS:84906782614
SN - 1545-598X
VL - 12
SP - 145
EP - 149
JO - IEEE Geoscience and Remote Sensing Letters
JF - IEEE Geoscience and Remote Sensing Letters
IS - 1
M1 - 6847134
ER -