Study of the Geometric Correction Methods Based on Optical Satellite Imagery with Rare Features

摘要

This paper puts forward a method of calculating accurately the geometric correction model parameters of SPOT imagery based on feature lines. First of all, calculating the corresponding ground coordinates with the image points on feature lines in the image space using satellite ephemeris parameters so as to obtain the initial parameters of correction model. Then, obtaining the accurate parameters of the correction model through the iterative calculation on the condition that the linear equations are regarded as the constraint condition of the correction model. Finally, achieving the accurate geometric correction of SPOT satellite image based on the correction model parameters. The mean square errors in the x and y directions are respectively 15.81 meters and 10.875 meters. According to the mapping requirement of topographic map in 1:50000, which the horizontal accuracy is not more than 25 meters in the flat or hilly terrain, and not more than 37.5 meters in the mountain land. The experimental results show that in the condition of the corresponding image points and the ground points aren't able to be obtained simultaneously, the correction precision of SPOT5 satellite images using the control line features can meet the mapping requirement of topographic map in 1:50000.