Nearly Zero Inclination Geosynchronous SAR Mission Analysis With Long Integration Time for Earth Observation
Nearly Zero Inclination Geosynchronous SAR Mission Analysis With Long Integration Time for Earth Observation
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DOI：
10.1109/tgrs.2013.2296357
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发表时间：
2014-10-01
影响因子：
8.2
通讯作者：
Rocca, Fabio
中科院分区：
文献类型：
--
作者：
Ruiz-Rodon, Josep;Broquetas, Antoni;Rocca, Fabio
分析了近零倾角低偏心率同步轨道合成孔径雷达（GEOSAR）中纬度（30 ° ~ 60 °）对地观测使命的性能。这类卫星相对于地球表面的缓慢运动使得有必要考虑在数小时内对脉冲进行长时间相干组合，以达到所需的沿轨道分辨率。被认为是一个系统的基础上适度的发射功率和天线尺寸。在这种GEOSAR系统中，必要的灵敏度是从使用高于多普勒带宽的脉冲重复频率和长积分时间的原始数据的累积能量中获得的。分析了长时间捕获所带来的目标与大气相位屏的去相关、相干斑噪声对接收信号的影响以及卫星位置保持要求等问题。将这种系统置于广播通信卫星上的可行性使近零倾角的GEOSAR成为目前搜索和救援任务的一种低成本替代方案。
In this paper, the performance of a nearly zero inclination and low eccentricity geosynchronous synthetic aperture radar (GEOSAR) mission for midlatitude (30 degrees-60 degrees) Earth observation is analyzed. The slow motion of such satellites with respect to the Earth's surface makes it necessary to consider long coherent combination of pulses during hours to reach the desired along-track resolution. A system based on moderate transmitted powers and antenna sizes is considered. The necessary sensitivity in such GEOSAR system is obtained from the accumulated energy of the raw data using a pulse repetition frequency above the Doppler bandwidth and a long integration time. Several issues as a result of the long acquisition, such as target and atmospheric phase screen decorrelation, speckle noise impact on the received signal, and satellite station-keeping requirements, are analyzed. The feasibility of such systems to be placed on a broadcasting communication satellite makes nearly zero inclination GEOSAR a low-cost alternative of current SAR missions.