Method for measuring radiant illumination of earth albedo

Abstract

The invention discloses a method for measuring the radiant illumination of earth albedo, and the method comprises the following steps of: establishing an earth coordinate system by using an earth core as a coordinate original point, and determining the longitude and latitude positions of the earth coordinate system of a satellite and the sun at a special moment according to the satellite orbit parameters and the mounting positions of a star sensor on the satellite; dividing the surface of an earth in a longitude and latitude manner, selecting a small surface element on the earth surface, and judging whether the small surface element can be irradiated by the sun and further be viewed by a light screening cover of the star sensor simultaneously or not; and if the small surface element can be irradiated by the sun and further be viewed by the light screening cover of the star sensor simultaneously, calculating stray light influence of sunlight scattered by the small surface element on the star sensor according to a radiation transmission relation of the sun, the surface elements and the star sensor. Comprehensive influences of the earth surface on the star sensor can be obtained by traversing each surface element of the earth surface and overlapping the stray light influences of each surface element on the star sensor. The method disclosed by the invention has the advantages of fast calculation speed and high measurement accuracy.

Description

technical field [0001] The invention relates to a method for measuring the irradiance of the earth's albedo, and belongs to the technical field of star sensor design. Background technique [0002] The star sensor has the characteristics of high precision and high integration, and can provide three-axis attitude information, which makes it gradually become an important attitude measurement equipment in space vehicles such as satellites or missiles. The star sensor measures the three-axis attitude of the satellite relative to the celestial coordinate system by sensing star radiation. Stellar radiation is generally weak, and the stray light in the space environment will interfere with the weak starlight sensitive to the star sensor, reducing the imaging quality of the system, and in severe cases, it will drown out the star light intensity, making the star sensor unable to work normally. Therefore, to determine the stray light effect of the star sensor in orbit and to ensure i...

AI Technical Summary

Problems solved by technology

For star sensors flying in space, the area of ​​the earth's albedo is very large, and to obtain an accurate effect of the earth's albedo, it is necessary to trace a large number of earth's albedo rays, which poses a challenge to the existing stray light analysis software and computer hardware. Extremely demanding; when the number of tracing rays is small, the correctness and accuracy of the calculation results are difficult to guarantee

Moreover, it is difficult to combine the relative position of the sun and the satellite when the star sensor is in orbit, and the surface albedo of the corresponding geographical location on the earth's surface by using the existing software simulation.

This brings great difficulty to analyze the stray light effect of the earth albedo on the star sensor

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