Considerations for SAR image quantification unique to orbital systems
Considerations for SAR image quantification unique to orbital systems
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DOI：
10.1109/36.83990
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发表时间：
1991-09
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影响因子：
--
通讯作者：
R. Raney
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文献类型：
--
作者：
R. Raney
本文讨论了合成孔径雷达（SAR）对点散射体和分布散射体响应的定量表达式，用于标定和偏振测量。图像增益取决于观测的几何形状，这与平坦地球的情况不同，后者通常被认为适用于轨道几何形状。图像的信噪比依赖于足迹速度，而分布散射体的平均杂声比依赖于航天器速度。例如，当轨道SAR观测到的分布式场景图像要通过与参考点散射体的脉冲响应进行比较来校准时，速度比会进入峰值功率表达式，但当对脉冲响应使用积分时，速度比不会进入表达式。通过对脉冲重复频率的采样，研究了方位角上图像像素重叠所产生的处理增益。>
A discussion is presented of quantitative expressions required for the response of a synthetic aperture radar (SAR) to both point and distributed scatterers for purposes such as calibration and polarimetry. Image gains depend on the viewing geometry, which is unlike the flat Earth case, which often is assumed to apply in an orbital geometry. Image signal-to-noise ratio is dependent on footprint velocity, but the mean clutter-to-noise ratio for distributed scatterers is dependent on spacecraft velocity. When imagery of a distributed scene observed by an orbital SAR is to be calibrated by comparison to the impulse response of a reference point scatterer, for example, the velocity ratio enters the expression for peak power, but does not enter when an integral is used over the impulse response. The author also looks at the processing gain resulting from overlapping image pixels in azimuth through sampling of the pulse repetition frequency. >