J4 ›› 2015, Vol. 42 ›› Issue (2): 28-34.doi: 10.3969/j.issn.1001-2400.2015.02.005

• Original Articles • Previous Articles     Next Articles

Squinted high resolution SAR based on the  frequency synthetic bandwidth

SHAO Peng;XING Mengdao;LI Xueshi;LI Yachao   

  1. (National Key Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2013-11-14 Online:2015-04-20 Published:2015-04-14
  • Contact: SHAO Peng E-mail:shaopeng987917@126.com

Abstract:

Due to the problem of high grating-lobe caused by phase discontinuity for frequency bandwidth synthetic, a new method of frequency synthetic bandwidth is proposed. The cause for phase discontinuity of frequency spectrum is the relative motion between radar and scatterers. The phase error for every sub-pulse according to different forms of the slant range between radar and scatterers is compensated by this method. A new approach is put forward for step frequency signal processing after the frequency band is synthesized. First, the pulse is compressed and frequency band is synthesized. After the frequency band is synthesized, the second range compression and the range migration correction are implemented. Then, phase discontinuity due to the corrected range migration correction is avoided. Finally, Chirp Scaling is applied to obtain the squint two-dimension high resolution SAR (Synthetic Aperture Radar, SAR) image. In order to identify the availability of this method, simulation results are shown in the paper. Experiments on raw data and simulation show that the wide-band signal could be synthesized by the narrow-band stepped signal.

Key words: stepped frequency signal, high squinted, frequency bandwidth synthetic, phase discontinuity, slant-range error