The Research On Geometric Positioning Of Space-Based Optical Image Based On Feature Points

The earth observation and measurement technology of satellite, one of the important means for human to obtain the earth space information, plays an important role in the national economy and national defense construction. Along with the development of satellite remote sensing technology of our country, the high precision technology and method of geometric positioning become a bottleneck restricting the development and application of satellite remote sensing system in our country. This paper took some in-depth research around the related technology of geometric positioning of space-based optical image, and obtained the certain research results. The specific contents are as follows:(1) introduce a number of basic theories of geometric positioning technology of space-based optical image, including the satellite reference coordinate system and conversion relationship with each other, imaging model of space-based sensor, geometric positioning method, factors influencing geometrical positioning;(2) study the method of satellite attitude determination under the condition of high frequency jitter, put forward an estimation method of satellite attitude dither based on compressed sensing and least squares, achieve the determination of the high accuracy satellite attitude under the condition of high frequency jitter;(3) study the imaging process inside the camera, establish the model of optical imaging instrument misalignments. Try to reduce model complexity and the number of estimated parameters of model by simplifying the model and optimize the model, which improves the usability and applicability of the model;(4) study the method of the feature point sampling and purifying in the geometric positioning of space-based optical image, proposes a sampling method of feature points based on RIC and a method of the feature points purifying based on RANSAC, which can obtain the optimization distribution of feature point and achieve the purpose of purification of feature point, which improves the accuracy of geometric positioning.The paper has certain reference value for the further study the geometric positioning of space-based optical image.