星载PALSAR影像几何精度定量评价与误差分析

Quantitative assessment and error analysis of geometric accuracy for satellite-borne PALSAR images

选择有代表性的星载PALSAR影像,利用Doppler、距离、椭球方程建立其成像模型,对其几何定位精度进行了试验,获得了它的几何系统误差和几何纠正误差的定量值。根据地面高程误差是影响SAR影像几何纠正精度主要因素的原理,利用计算机仿真技术定量系统地分析了地面高程误差对其几何纠正精度的影响,获得了地面高程误差对视角的影响、视角误差对影像几何精度的影响以及单位高程误差对影像几何精度的影响等定量结论及影响变化规律,为PALSAR影像的处理与应用提供了科学的依据,更重要的是为SAR影像几何精度分析和误差分析提供了一种新的定量方法。

The geometric accuracy of Synthetic Aperture Radar （SAR） is one of key factors influencing its final application. However, the method of quantitative accuracy assessment and error analysis for SAR imagery is still very lacking. This paper chose the representative satellite-borne PALSAR images to implement the experiments on geometric positioning accuracy, through establishing the imaging model with Doppler, slant range and the earth ellipsoid equations, and obtained the quantitative values of the systemic geometric errors and rectification errors. Subsequently, according to the fact that the elevation error is the main error source influencing the geometric rectification precision, computer simulation is used to discuss the systemic influence on the geometric rectification accuracy quantitatively, and the corresponding effect regularity from different facets is put forward, e. g. , elevation error to the view angle, the error of view angle to geometric accuracy, and the unit elevation error to the geometric accuracy. It can provide some scientific evidence on the image processing and application of PALSAR images, more important, a new method for quantitative error analysis and geometric accuracy analysis of SAR images.