Title :
Advanced range migration algorithm for ultra-high resolution spaceborne synthetic aperture radar
Author :
Tao Zeng ; Wenfu Yang ; Zegang Ding ; Luosi Liu
Author_Institution :
Sch. of Inf. & Electron., Beijing Inst. of Technol., Beijing, China
fDate :
8/1/2013 12:00:00 AM
Abstract :
To achieve ultra-high resolution images, processing algorithm of spaceborne synthetic aperture radar (SAR) faces significant challenges such as the curved orbit, the unneglectable propagation time and the space-variant effective velocity. In the light of imaging requirements of the ultra-high resolution spaceborne SAR, an advanced range migration algorithm (ARMA) is presented in this study. Firstly, a new slant range model is developed by incorporating straight orbit approximation with additional linear, cubic and quartic term. Subsequently, a two-dimensional spectrum is derived by making use of Fourier transform pairs and the approximate azimuth stationary point based on the new range model. Finally, a novel RMA is derived. In this algorithm, the accurate range cell migration correction (RCMC) is done through two steps: the effective velocity dependence RCMC and the bulk RCMC, and the range-variant azimuth filtering is accomplished. Simulations are carried out to verify our proposed algorithm, which indicate that ARMA can keep precise even the resolution is up to decimeter level.
Keywords :
Fourier transforms; filtering theory; image resolution; radar imaging; radar resolution; spaceborne radar; synthetic aperture radar; ARMA; Fourier transform pairs; RCMC; advanced range migration algorithm; approximate azimuth stationary point; cubic term; imaging requirements; linear term; quartic term; range cell migration correction; range-variant azimuth filtering; slant range model; space-variant effective velocity; spaceborne SAR; straight orbit approximation; two-dimensional spectrum; ultra-high resolution image processing algorithm; ultra-high resolution spaceborne synthetic aperture radar; unneglectable propagation time;
Journal_Title :
Radar, Sonar & Navigation, IET
DOI :
10.1049/iet-rsn.2012.0124