Research On Beacons Precise Positioning Algorithm For Deep Space Optical Communication

In deep space optical communication,the pointing acquisition and tracking(PAT)system needs to locate the position of the beacon to establish and maintain the connection between the spacecraft optical communication terminal and the ground station.Compared with near-Earth satellite optical communication,the deep-space optical communication has a longer wavelength distance and requires higher accuracy for interconnection positioning.The traditional way of transmitting beacon light as a positioning beacon is limited by laser power.At deep space distances,the attenuation is severe,and the realization is difficult and cost ly,and the method based on the natural celestial body image as a beacon has attracted attention.Based on this,this thesis studies the precise positioning of beacons.This paper analyzes the positioning process of deep space optical communication by establishing a beacon image model under deep space optical communication.The positioning algorithm is designed to target the characteristics of the image based on the beacon image features.Considering the long distance of deep-space optical communication,small target beacons,and large uncertain areas,the methods of coarse positioning and fine positioning are adopted.First,coarse positioning is performed based on the image edge feature information.After locating the target in the uncertain area,the field of view is reduced to improve the beacon image resolution,and the positioning is based on the detailed features of the beacon image.Use feature point matching to track and locate images.The effect of celestial body rotation is discussed.Based on the mapping relationship between geometric transformation and coordinates,the effect of celestial body rotation on image transformation is analyzed.Through the algorithm test on the simulation image and the actual experimental image,the feasibility of the algorithm is verified.The influence of celestial body rotation is discussed.Based on the mapping relationship between geometric transformation and coordinates,the influence of celestial body rotation on image transformation is analyzed.For the real-time requirements of the deep-space optical communication beacon positioning system,the field programmable gate array(FPGA)hardware implementation algorithm is analyzed and designed,and the hardware implementation is divided into modules.The pipeline structure and parallel calculation are used to process the image data.The functional simulation and board-level testing of the module were conducted respectively.The algorithm hardware is designed as a reference for the real-time performance of the optical communication positioning system.