High Squint SAR Imaging Using the Modified Range-Doppler Algorithm
Based on the imaging geometry of squint mode, the characteristics of echoes based on four order approximate expressions in slow time domain in squint mode are analyzed in this paper. The conclusion that the influence of range walk is much larger than range bending in high squint mode is drawn. The traditional Range-Doppler algorithm is no longer suitable for high squint SAR imaging. Based on the conclusion a modified Range-Doppler algorithm suitable for high squint SAR imaging is derived in this paper. At first range walk is corrected in range frequency domain to make the coupling between range and azimuth small. After that, range compression, secondary range compression, azimuth compression and higher order phase correction are presented in the modified algorithm. Compared with the traditional Range-Doppler algorithm, the imaging results of simulation are presented to demonstrate the accuracy and validity of the proposed algorithms in high squint SAR imaging.
KeywordsSynthetic aperture radar High squint mode Modified range-Doppler algorithm Range walk
The author thanks Pro. LV for his constant support. The discussions with his classmates were very important for his research.
- 1.Li Y (2008) The imaging techniques of Missile-borne synthetic aperture radar. NUDT, ChangshaGoogle Scholar
- 2.Sun XB, Yeo TS (1999) Time-varying step-transform algorithm for high squint SAR imaging. IEEE Trans GRS 37(6):2668–2677Google Scholar
- 3.Han C, Wang J, Chen Z (2002) An algorithm for squint SAR imaging. J Electron Inform Tech 24(6):816–819Google Scholar
- 4.Bao Z, Xing M, Wang T (2005) Radar imaging technology. Electronic industry press, BeijingGoogle Scholar
- 5.Jing W, Zhang L, Xing M (2009) Algorithm for wide-swath spotlight SAR data processing. ACTA Electron Signal 37(3):470–475Google Scholar
- 6.Liu G, Liang D (2004) A suitable study of chirp scaling algorithm. Mod Rad 26(3):50–53Google Scholar