A star point image enhancement method for star sensor

Abstract

The invention discloses a star sensor star point image enhancement method, which is a superposition enhancement method after reconstruction of a star point image. Through motion information acquired by the star sensor and a star point extraction and recognition result of the current frame, a nonlinear model for star point motion is adopted to realize star point position prediction and tracking andrecognition in a next frame, and position prediction results of star points at different positions in an image plane are more accurate; by using the predicted star point position and the star point information in the former frame, a star point motion energy distribution model is used to generate one frame of noise-free simulated star map, the energy distribution is closer to the actual star points, no complex matching alignment process is needed, better star point superposition enhancement effects can be obtained, and the star point extraction precision is improved. The method is suitable when the star sensor is in a static condition and a dynamic condition, star point position prediction and tracking and recognition can also be realized, the star sensor processing time is further reduced, and the star sensor attitude output errors are reduced.

Description

technical field [0001] The invention relates to a star point image enhancement method of a star sensor, in particular to a method for improving the signal-to-noise ratio of the star point image by superimposing and filtering after the star point image is reconstructed. Background technique [0002] The star sensor takes the star as the observation object, and is the sensor with the highest precision among the existing absolute attitude measurement devices. The measurement accuracy can reach the sub-arc second level and does not change with time. It is widely used in the fields of accurate attitude measurement and navigation of ships and so on. Under static conditions, the star image point of the star sensor is affected by noise such as shot noise, background radiation noise, readout noise, dark current noise, etc., resulting in a decrease in the signal-to-noise ratio and an increase in the error of star point position extraction. The traditional denoising method can reduce ...

AI Technical Summary

Problems solved by technology

The position of the center of mass of the same navigation star is different in different frames, and the energy distribution of the star point will also change with the different positions of the center of mass in the pixel. The simple superposition of the image does not redistribute the corresponding sub-pixel energy distribution of the star point, and the noise in different frames is also superimposed at the same time, and the final image enhancement effect is limited

Images