机载合成孔径雷达图像几何纠正方法研究

机载合成孔径雷达图像几何处理是机载合成孔径雷达图像后续处理的基础,同时也是机载合成孔径雷达大规模测绘应用的基础。本文根据机载合成孔径雷达图像的成像机理,基于距离多普勒模型,考虑到合成孔径雷达成像时斜视角与多普勒频率的关系,在影像纠正时,将斜视角作为一个变量处理来减小雷达成像时零多普勒误差的影响。试验证明,此种方法比将斜视角作为零处理时的纠正精度有明显提高。详细地分析了利用此方法进行几何纠正时控制点的个数和分布对纠正精度的影响。

Study on geometric rectifying methods of airborne synthetic aperture radar image

Geometric processing of Airborne Synthetic Aperture Radar (SAR) image is not only the foundation of post-processing but also the foundation of large scale of application in surveying and mapping of Airborne SAR image.Based on the imaging mechanism of airborne SAR image and the Range-Doppler model,considered the relation of squint angle and Doppler frequency,this paper took squint angle as a variable to reduce the effect of the zero Doppler error when rectifying the SAR image.Experiment indicated that the accuracy of this method was higher than the method which took squint angle as zero.The effect of the numbers and distributions of the control points to the rectified accuracy when using this method to rectify airborne SAR image was analyzed in detail.