天绘二号卫星单幅SAR影像定位性能评估

Target location performance evaluation of single SAR image of TH-2 satellite system

为了评估天绘二号卫星单幅SAR影像定位性能,本文采用了基于距离-多普勒模型、地球模型与数字高程模型进行定位的理论与方法,从预测像点坐标及地面定位两个方面进行定位试验,并对结果进行分析。利用不同地区的3景天绘二号卫星主星SAR影像进行定位试验,其中预测像点精度在1像素左右,地面定位精度在2 m以内。结果表明天绘二号卫星系统参数可靠,具备高精度定位能力,可以为地面定位、生成雷达正射影像等任务提供可靠数据保证。

In order to evaluate the target location performance of a single SAR image of TH-2 satellites, this paper uses the theory and method of target location using the Range-Doppler model, Earth’s ellipsoidal model and digital elevation model in the positioning experiments, and analyzes the experimental results from two aspects of predicting image point coordinate and positioning the ground target. Using three TH-2 SAR images in different regions to conduct experiment, it is concluded that the predicting image point accuracy is about 1 pixel and the ground target positioning accuracy is less than 2 m. The results show that the TH-2 satellite system has reliable system parameters and high precision positioning capability, which can provide reliable data for the ground target locating, the radar orthophoto image generation and other tasks.