星载高分辨率滑动聚束SAR系统采用方位向大转角技术来实现高分辨率与宽测绘带的折中,系统在大转角时场景回波的距离徙动非常大,单一回波窗无法适应大距离徙动。基于这一问题本文提出一种非基带插值方位预处理方法,系统采用分段变重频技...星载高分辨率滑动聚束SAR系统采用方位向大转角技术来实现高分辨率与宽测绘带的折中,系统在大转角时场景回波的距离徙动非常大,单一回波窗无法适应大距离徙动。基于这一问题本文提出一种非基带插值方位预处理方法,系统采用分段变重频技术实现对回波的全覆盖。通过二维时域对回波沿方位向分块,采用非基带插值对分段后的时域信号进行重采样,得到不同PRF下的均匀化数据。仿真结果表明,该方法有效实现了数据的均匀化预处理,与传统处理方法相比成像结果的方位分辨率提高,PSLR、ISLR得到4 d B以上的改善。展开更多
For a synthetic aperture radar（SAR） system mounted on a geostationary Earth orbit（GEO） satellite, the track can be curvilinear. Thus, a bistatic SAR system based up on geostationary transmitter and ＂receive-only...For a synthetic aperture radar（SAR） system mounted on a geostationary Earth orbit（GEO） satellite, the track can be curvilinear. Thus, a bistatic SAR system based up on geostationary transmitter and ＂receive-only＂ SAR system onboard airplanes, namely GEO spaceborne-airborne bistatic（GEO SA-Bi SAR）, is significantly different from the traditional bistatic SAR. This paper mainly studies the resolution characteristic of the sliding spotlight GEO SA-Bi SAR system. Firstly, the common azimuth coverage and coherent accumulated time are theoretically analyzed in detail. Then,based on the gradient method, the accurate two dimensional resolution of a GEO SA-Bi SAR system is analytically calculated. Finally, the simulation data show the correctness and effectiveness of the proposed resolution analysis method.展开更多
文摘星载高分辨率滑动聚束SAR系统采用方位向大转角技术来实现高分辨率与宽测绘带的折中,系统在大转角时场景回波的距离徙动非常大,单一回波窗无法适应大距离徙动。基于这一问题本文提出一种非基带插值方位预处理方法,系统采用分段变重频技术实现对回波的全覆盖。通过二维时域对回波沿方位向分块,采用非基带插值对分段后的时域信号进行重采样,得到不同PRF下的均匀化数据。仿真结果表明,该方法有效实现了数据的均匀化预处理,与传统处理方法相比成像结果的方位分辨率提高,PSLR、ISLR得到4 d B以上的改善。
基金supported by the National Natural Science Foundation of China(61271342)
文摘For a synthetic aperture radar（SAR） system mounted on a geostationary Earth orbit（GEO） satellite, the track can be curvilinear. Thus, a bistatic SAR system based up on geostationary transmitter and ＂receive-only＂ SAR system onboard airplanes, namely GEO spaceborne-airborne bistatic（GEO SA-Bi SAR）, is significantly different from the traditional bistatic SAR. This paper mainly studies the resolution characteristic of the sliding spotlight GEO SA-Bi SAR system. Firstly, the common azimuth coverage and coherent accumulated time are theoretically analyzed in detail. Then,based on the gradient method, the accurate two dimensional resolution of a GEO SA-Bi SAR system is analytically calculated. Finally, the simulation data show the correctness and effectiveness of the proposed resolution analysis method.
