Method for extracting fixed star image coordinates in real time based on field programmable gate array (FPGA)

Abstract

The invention relates to a method for extracting fixed star image coordinates in real time based on a field programmable gate array (FPGA). According to the method, fixed star imaging of a star sensor adopts a sub pixel technology, the center of mass of the fixed star image coordinates is acquired through a center-of-gravity method, and only a gray value of the previous column of coordinates of the current row of the current image pixels and a gray value of the previous row of coordinates of the current column are adopted in the process of extracting the fixed star image coordinates. According to the method, after analog / digital (A / D) conversion is completely changed into digital quantity, the fixed star image coordinates of the image are immediately extracted. Therefore, the process that the star map data is required to be read from a static random access memory (SRAM) in the process of extracting the traditional fixed star image coordinates is avoided in the process of extracting the fixed star image coordinates. According to the method, the process of saving a star map to the SRAM and the process of extracting the fixed star image coordinates from the star map are completely parallel; and therefore, the time of extracting the fixed star image coordinates is reduced, the real-time property and the data updating rate are improved, and further the dynamic performance of the star sensor is further improved.

Description

technical field [0001] The invention relates to a method for realizing real-time extraction of stellar image coordinates based on FPGA. Background technique [0002] With the development of aerospace technology, star sensors, as a high-precision attitude measurement device, are more and more widely used in satellites and other spacecraft. The star sensor is mainly composed of an optical system, an image sensor circuit and a digital image processing system. The working principle of the star sensor is: the starlight emitted by the star is imaged on the photosensitive surface of the CCD through the optical system, the light energy of the starlight is converted into an analog electrical signal by the CCD signal detection circuit, and the analog signal processing unit amplifies, filters, After shaping and other processing, the analog-to-digital conversion unit performs analog-to-digital conversion and data acquisition. The data processing unit processes the digitized star map, ...

AI Technical Summary

Problems solved by technology

The method of extracting star image coordinates by reading images from SRAM must utilize the gray value of the next column coordinates of the current image pixel and the gray value of the next row coordinates of the current column in the process of extracting star image coordinates. Therefore, the method of extracting stellar image coordinates by reading images from SRAM cannot meet the high dynamic and high-precision mode requirements of future star sensors

Images