Star point extraction system and method of star sensor

Abstract

The invention discloses a star point extraction method of a star sensor. The method comprises the following steps: establishing a star point energy distribution model under a dynamic condition; predicting a current moment coordinate of the star point, and windowing by taking the current moment coordinate of the star point as a center; taking the star point energy distribution model under the dynamic condition as a template, calculating correlation point by point in a window, and taking a region with the maximum correlation as a region where a star point is located; and covering the region where the star point is located by using the star point energy distribution model under a dynamic condition, and calculating the coordinates of the star point by using a gray weighted centroid method. According to the invention, the star sensor dynamic model is used as a template, and the correlation is used as a basis so that the star point extraction rate and extraction precision of the star sensor under a large dynamic condition are ensured, and the dynamic performance of the star sensor is improved.

Description

technical field [0001] The invention relates to space control technology, in particular to a star point extraction system and method for a star sensor. Background technique [0002] The dynamics of the star sensor refers to the ability of the star sensor to adapt to the rotation when the spacecraft rotates at a certain angular velocity, which is an important indicator of the star sensor. Satellites have requirements for the dynamic performance of star sensors in large dynamic situations such as initial orbiting, maneuvering, and large-angle attitude adjustment. More applications of star sensors on high-mobility spacecraft such as space maneuvering platforms and missiles are based on star sensors. Higher requirements are put forward for the dynamic performance. [0003] The difficulties in improving the dynamics of the star sensor are as follows. Since star sensor imaging is a process of energy integration, the energy distribution of its imaging spot (star point) is related...

AI Technical Summary

Problems solved by technology

For the current conventional star point extraction method, the star point extraction is mainly based on the gray threshold of the image and the connected domain as the criterion, and the star point extraction ability is not strong under large dynamic conditions.

The main difficulty is that when the exposure time is long, the "tail" of the star point is too long to easily lead to breakage, and the star point trajectory is divided into several segments, resulting in the failure of the conventional star point extraction method; after shortening the exposure time, the star point can be shortened. Point tailing reduces the possibility of fracture, but it will cause the total energy of the star point received by the detector to decrease, and the signal-to-noise ratio will decrease, making it difficult to extract the star point

Images