A method for extracting the parameters of sensitive objects for stationary satellite imaging navigation and registration

Abstract

The invention provides an extracting method for fixed star sensitive east and west parameters of stationary satellite imaging navigation and registration. The extracting method comprises the following steps of obtaining a changing curve of a total gray value of pixels of each line along with time; obtaining a moment that a fixed star image center crosses a center line of the pixels of the line; fitting a motion law of the fixed star image center in east and west line coordinates of a satellite remote sensing detector array; obtaining a moment that the fixed star image center crosses a center line of the east-west direction of the satellite remote sensing detector array. According to the extracting method provided by the invention, high-frequency error of star positions caused by factors such as optical imaging of the detector, circuit noises, high-frequency wobble of a satellite and the like can be eliminated by multiframe data information fusion processing and curve fitting, thereby improving the identification accuracy of fixed star position parameters. The extracting method can be used for stationary satellite imaging navigation and registration, and has important significance for improving on-orbit thermal deformation precision of a remote sensing imaging system and the imaging navigation and registration processing property by acquiring parameters such accurate time and the like that the fixed star crosses the center of the detector array.

Description

technical field [0001] The invention relates to the overall technology of space vehicles and the field of satellite digital signal and image processing, in particular to a method for extracting parameters of stationary satellite imaging navigation and registration star sensitive objects. Background technique [0002] With the improvement of the application technology of remote sensing satellites, it is usually required that the images of the ground imaged by high-precision geostationary satellites be precisely positioned and registered to the nominal grid of the earth. However, satellite platforms and remote sensing instruments are affected by factors such as space mechanical environment and thermal environment changes. Satellites will have orbital drift and attitude pointing deviations, and instruments will produce geometric deformation, which will affect the positioning and registration accuracy of remote sensing images. The "satellite imaging navigation and registration" ...

AI Technical Summary

Problems solved by technology

[0003] In the process of constant center sensitivity, the effective projection of a star with a small brightness in the detector array may be smaller than the size of a pixel, and when the projection is completely inside a certain pixel, the single exposure data cannot be used to determine the star’s The specific position within this cell, which will lead to low accuracy of feature point extraction

In addition, the imaging process will be interfered by various random noises, which will increase the error of feature point extraction.

[0004] The NOAA research report (1989, No. N90-13422) written by J.L Fiorello et al. introduced the concept and principle of image navigation registration, and proposed a method to obtain instrument deformation parameters by observing stars with instruments, but did not elaborate on image data. The processing method of; U.S. Patent: Method and apparatus for radiometer starsensing (patent No. US4801202) has described the method that the radiometer of geostationary meteorological satellite observes stars in orbit, discloses the technical scheme to specific operation steps etc., but does not set forth to many The processing method of frame star sensitive image data; U.S. Patent: Sightings by satellite for image navigation (Patent No. US US4746976) introduces the location and number of stars observed by stationary meteorological satellite instruments on orbit, and discloses the selection of stargazing timing and direction and other methods, but did not elaborate on the content of extracting east-west direction parameters for multi-frame stellar sensitive image data; the article "Fengyun No. 4 Meteorological Satellite Scanning Imager - Visible Light Channel Stellar Sensitivity" introduced the method of Fengyun No. 4 satellite scanning imager to solve the internal deformation of the instrument through star sensitivity, and proposed to obtain the position of the star passing through the detector through weighted analysis, but There is no fusion of data from multiple columns of detectors, and the error of the east-west mirror is large

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