Method for star point extracting of navigational star in cloud environment in daytime

Abstract

The present invention provides a method for star point extracting of a navigational star in cloud environment in daytime, and the method comprises firstly, respectively performing the following operation on each frame of star map of a plurality of frames of daytime cloud star maps which are consecutively taken: (1) using an improved morphological TopHat operator to filter an original start map to obtain a first star map; (2) using a RobinsonGuard filter to filter the first star map to obtain a second star map; (3) using an adaptive threshold method for threshold cutting of the second star map, and storing coordinates and grayscales of all pixels higher than a threshold; and (4) using a clustering method for four-connected domain star point extracting; secondly using a multiframe comparison technique to eliminate pseudo-star points in the connected domain extracted from each frame of star map; and thirdly, calculating the centre of mass of each successfully-compared connected domain to complete the star point extraction. The method can effectively eliminate the interference of daytime sky clouds and other backgrounds, meanwhile avoids mistaken extraction caused by dust and other air floating objects, and ensures the effective and stable star point extraction.

Description

technical field [0001] The invention relates to a method for extracting navigation star points in a cloudy daytime environment, which is applied to the field of star map processing of near-ground platforms such as aircraft, missiles, ships and near-space vehicles. Background technique [0002] The star sensor is a high-precision attitude measuring instrument with stars as the measurement reference source. It has the advantages of high precision and strong autonomy, and has been widely used in space vehicles such as satellites and spacecraft. At present, most typical star sensors work in the cold and dark background and in the visible spectrum. Faced with the all-day navigation requirements of aircraft, missiles, ships and other platforms in the atmosphere and near-Earth space, due to the strong background light of the sky in daytime conditions , the traditional star sensor star point extraction technology can not meet the requirements. [0003] The day star sensor works in ...

AI Technical Summary

Problems solved by technology

[0014] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a method for extracting navigation star points in a cloudy environment during the day, and to solve the problem that the star sensor cannot work when it is disturbed by sky background radiation and clouds in the atmosphere. The problem of extracting star points

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