Research On Laser Pointing Correction Technology Based On Image Processing

With the development of satellite laser ranging technology,satellite ranging system is required to have a high level of automation.Laser pointing error correction technology is an important part of the ranging system,has gradually become a research hotspot in this area.In recent years,scholars’ research on image processing methods in this technology mainly focuses on laser-tip positioning and target satellite positioning.However,due to some problems in strong noise background environment,there are large deviations in positioning results.In order to improve the pointing correction efficiency of the system,it is necessary to further explore the laser pointing error correction.By analyzing the deviation source of laser pointing error correction,an image processing method of laser pointing error correction is proposed in this paper.Aiming at the CCD laser image,the foreground information of laser-tip and target satellite is extracted by bilateral filtering method,gamma transform method and OTUS method.Secondly,shape of the lasr-tip and target satellite are depicted and separated by various morphological processing methods.For the separated laser-tip graph,the radon transform method and k-means clustering analysis method are used to accurately fit the position of the laser-tip.For the separated satellite graph,the problem of interfering star is solved by image superposition and quadratic threshold segmentation,and the target satellite position is accurately extracted by the centroid method with threshold.At the same time,in order to facilitate the ground personnel to visually check the error correction,the judgment method is designed based on whether the circumscribed circles of the calibration points intersect.At present,this program has been successfully applied to the ground-based laser positioning system in Urumqi Meteorological Satellite Ground Station,the on-line real-time correction of laser pointing error is realized,controlling the pointing accuracy within 2 arc seconds.It is a great practical significance to promote the automatic development of satellite laser ranging system.