J4 ›› 2014, Vol. 41 ›› Issue (5): 42-47+104.doi: 10.3969/j.issn.1001-2400.2014.05.008

• Original Articles • Previous Articles     Next Articles

Unambiguous estimation of the radial velocity of a moving target by the range frequency maximum likelihood method

ZHANG Xuepan;LIAO Guisheng;ZHU Shengqi;GAO Yongchan;YANG Dong   

  1. (National Key Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2013-05-26 Online:2014-10-20 Published:2014-11-27
  • Contact: ZHANG Xuepan E-mail:xpzhang7@163.com

Abstract:

The radial velocity of a moving target should be estimated unambiguously in the synthetic aperture radar-ground moving target detection system. Estimation performance of the conventional maximum likelihood method based on multi-channel would decline when the radial velocity approaches the maximum unambiguous velocity. To solve these problems, the ML estimation method based on the range frequency interferometric phase is proposed in this paper. Compared with the conventional method, the proposed method weakens the effect of probability density function spreading. The radial velocity can be estimated accurately even when it approaches the maximum unambiguous velocity. The effect of noise on radial velocity estimation is also analyzed from two aspects of correlation coefficient and interferometric phase, which can be reduced by increasing independent samples. Numerical and real data are processed to demonstrate the effectiveness of the proposed method.

Key words: synthetic aperture radar, ground moving targets indication, unambiguous radial velocity estimation, maximum likelihood method, range frequency interferometric phase