Research On Landmark Matching And Channels Registration Of Pointing Correction Of Three-axis Geostationary Remote Sensing Satellite

In the geostationary remote sensing satellite orbit operation,an error of geometric would be happened to satellite's pointing to the ground,since the influences suffered from inner factors and outer environment,and it will cause a large position error on the ground.This paper focused on the pointing modification of three-axis geostationary remote sensing satellite in different channels,and a pointing confirmation method which is suitable to different channels was proposed.The main work and innovations were as follows.1.Carry on the research of the data preparation and pre-processing.Three kinds of nominal grid data calculation method were summed up.The generative approach of rasterized coastline mask data and landmark dataset were given,and the resampling method of geostationary locating data was studied.In order to verify the validity of the algorithm,some tests were designed to compare the differences among different types nominal grid data;the vector coastline data was used to generate landmark template data and coastline mask data;and combined the pixel distribution characteristic of sensor,resampled the locator data,and the regular locator data was got.2.The pointing confirmation method of the visible light channel which had high resolution and strong radiation message was studied.With the matching efficiency and cloud cover under consideration,a landmark matching method combined the coarse matching and precise matching was proposed,which used the gradient information as the main measurement,and adopted the Zernike torque discrepancy and the difference of error ellipses as the auxiliary measurement.Lastly,RANSAC algorithm and resistance estimation method were adopted to improve the accuracy of pointing calculation.The tests' results showed that: this method could geostationary remote sensing satellite single channel visible image pointing determination efficiently.After pointing error correcting,the average difference was about 0.6 pixels.3.The pointing confirmation method of the channels which had low resolution and week radiation message was studied.Channel with obvious landmark radiation message was chose as the standard,and the moon was adopted as the observation source and matching sou rce,two registration coefficient calculation methods based on shape and based on gray level respectively were used to match images between channels.So that channels with unclear message also could be pointing confirmed.The experiment result showed that: registration between channels was implemented effectively in this method,the precision could reach sub-pixel accuracy.The positioning deviation rectify level of multi-channel registration map was equivalent to the single visible channel's.This technique had been applied in the online processing of related three-axis scanning geostationary remote sensing satellite data in our country.