几何纠正是遥感信息处理中的重要环节,它直接关系到信息提取的精度与实用程度.而现实中,由于地形图绘制年代久远,且保密性较高,往往会出现缺失而不能满足纠正精度的情况.据此本研究在上海地区1∶25 000大比例尺地形图缺失,1∶100 000地形图不能满足SPOT5影像纠正精度的情况下,结合ArcGIS、ENVI软件采用多种例尺地形图对SPOT5影像进行几何纠正,并对纠正精度进行了对比分析.结果表明:将多比例尺地形图综合纠正能使精度控制在1个像元之内,由此确立了现有条件下的最佳方案,为地形图缺失情况下平原地区的几何纠正提供了思路.
The geometric correction is an important step in the remote sensing information processing,and it is directly related to the precision and usefulness of information extraction.In reality,topographic mapping is aged and with a high secrecy,so it can′t satisfy the precision of correction once lost.This paper based on the situation that we lack of the large-scale(1∶ 25 000) topographic maps,and the 1∶ 100 000 topographic maps can′t satisfy the correction precision of SPOT5 image,combined with ArcGIS and ENVI software,we correct the SPOT5 image of major urban areas of Shanghai by using multi-scale topographic maps,then we analyze the precision.Results show that the precision can be controlled in one pixel if we integrate multi-scale topographic maps.Finally we establish the best under existing conditions so that we provide ideas for geometric correction of flat areas in the special situation.