高分七号卫星足印相机激光光斑中心定位方法研究

Laser Spot Center Positioning Method in Gaofen-7 Footprint Camera

使用足印相机同时对激光光斑和地表成像会导致相机中的激光光斑影像与地面影像重叠,造成激光光斑的中心定位精度较差。本文针对GF-7卫星足印相机实测的图像特点,提出地物噪声图像分类方法,优化高斯拟合光斑中心定位的处理流程,同时分析不同地物噪声背景下光斑图像的分类方法以及对应的光斑中心的提取精度。实验结果表明,所提方法在低中高的不同噪声条件下,中心定位精度分别为0.11,0.13,0.16 pixel,定位方差分别为0.020,0.262,0.341 pixel。在信噪比更好的夜间,光斑定位精度为0.02 pixel,定位方差为0.0036 pixel,说明噪声是影响光斑中心定位精度的最主要因素。

With a footprint camera for surface imaging of laser spot and at the same time,it will cause the laser spot image in the camera to overlap with the ground image,resulting in poor center positioning accuracy of the laser spot.In this paper,according to the characteristics of the images measured by GF-7 satellite footprint camera,the ground noise image classification method is proposed to optimize the Gaussian fitting spot at the same time,the classification method of the spot image and the extraction accuracy of the corresponding spot center under the background of different ground noise are analyzed.Experimental results show that the proposed method has a center positioning accuracy of 0.11,0.13,0.16 pixel,and a positioning variance of 0.020,0.262,0.341 pixel,respectively,under different noise conditions of low,medium,and high.At night when the signal-to-noise ratio is better,the spot positioning accuracy is 0.02 pixel,and the positioning variance is 0.0036 pixel,indicating that the noise is the most important factor affecting the spot center positioning accuracy.