静轨卫星扫描影像几何定位误差分析

本文根据线阵扫描成像机理,建立了静轨卫星线阵扫描影像几何定位模型。在考虑比例因子λ为变量情况下,对其外方位元素引起的定位误差进行严密地理论推导与定量分析。同时,利用矩阵理论与变换性质,使繁琐的定位误差推导过程与公式得以简化。根据定位误差公式,基于C++开发其原型系统,并从多个角度对静轨卫星扫描影像几何定位误差进行模拟实验。实验结果表明:单个外方位元素误差与之引起的定位误差之间,呈明显的线性正相关;外方位元素对中心点定位误差影响由大到小的顺序为φ、ω、α、β、H、κ;对边缘点定位误差影响由大到小的顺序为φ、ω、H、α、β、κ;从图像中心到图像边缘,φ、ω、H引起的定位误差逐渐增加,α、β引起的定位误差缓慢减小,κ引起的定位误差缓慢增加,综合定位误差逐渐增加,在边缘增加趋势明显。

Geometric Location Error Analysis of Geostationary Satellite Scan Imagery

Geometric correction and location error analysis of remote sensing image is an important aspect for image processing of remote sensing. But location error analysis for geostationary satellite imagery is little when scale factor A is as a variable. In this paper, according to linear array scanning imaging mechanism, we completed the establishment of scan line array geometry imaging equation and location model for geostationary satellite. Then, based on the geometric location model, considering the scale factor λ as a variable, a strict quantitative analysis and theoretical derivation of location error caused by external orientation elements was finished. At the same time, the use of matrix theory and transformation＇nature made the complicated process of location error and formula simplified. Finally, according to the location error formula,we have developed a prototype system for geometry location and error analysis of geostationary satellite imagery based on C ＋ ＋. And then, simulation experiments of geostationary satellite imagery from various angles were tried. The experimental results show that： an element error of single exterior orientation and the location error have obvious linear positive correlation ; the descending order of exterior orientation elements＇ impact for location error to center point is φ, ω, α ,β, Н , κ ; the descending order of exterior orientation elements＇impact for location error to edge point is φ, ω, α ,β, κ ; From the image center to the edge, location error caused by φ and to and H increases gradually, location error caused by α and β has a slow decrease; location error caused by K has a slow increase; When six exterior orientation elements all have the critical error, from the image center to the edge, the integrated location error increases gradually ; At the image edge, the rising trend of the integrated location errors is evident. The analytical method and conclusions in this paper provide support to the geometric error characteristics of geostationary satellite imagery, also is valuable to other remote sensing satellite platforms and the geometric correction of remote sensing images.