A method for on-orbit joint calibration of multi-beam spaceborne laser altimeter

Abstract

The invention discloses an on-orbit joint calibration method for a multi-beam satellite-borne laser altimeter. According to the method, a relative geometrical relationship between a reference beam andother beams is constructed by setting a reference beam, so that a multi-beam laser combined geometric calibration model is established. The method comprises the steps of setting a reference beam of the multi-beam satellite-borne laser altimeter, and constructing an on-orbit combined geometrical calibration model of the multi-beam satellite-borne laser altimeter; combining the geometric calibration models of the multi-beam satellite-borne laser altimeter, and resolving a geometric calibration error equation of the multi-beam satellite-borne laser altimeter; and performing laser pointing and ranging settlement on each beam of the multi-beam satellite-borne laser altimeter. The technical scheme of the invention aims to solve the problem of on-orbit calibration of the multi-beam satellite-borne laser altimeter, and provides a reliable on-orbit calibration method for the multi-beam satellite-borne laser altimeter which is already on orbit and is about to be launched at present.

Description

technical field [0001] The invention relates to the technical field of on-orbit geometric calibration of a spaceborne multi-beam laser altimeter, in particular to an on-orbit multi-beam spaceborne laser altimeter for high-precision geometric positioning of each beam of a multi-beam spaceborne laser altimeter joint calibration method. Background technique [0002] Geometric positioning accuracy is the most important index to measure the performance of surveying and mapping satellites, among which elevation accuracy is more important because it is difficult to improve. LiDAR (Light Detection And Ranging, referred to as LiDAR) has the characteristics of good directionality, high coherence, good monochromaticity, and high ranging accuracy. It has great application potential in the fields of deep space exploration and earth science. Onboard laser altimetry technology is applied to high-resolution optical three-dimensional surveying and mapping satellites, assisting space photogr...

AI Technical Summary

Problems solved by technology

However, due to the fact that the laser altimeter will produce many system errors such as pointing angle, centroid offset, and system clock synchronization during the measurement process, especially the pointing angle error, it may reduce the accuracy of the laser footpoint as the height control of the surveying and mapping industry.

Taking the influence of laser pointing angle error as an example, for an altimetry system with an orbital height of 500km, when the surface incident angle is 1°, a 30″ laser pointing error causes a horizontal error of 75m and a height error of 1.3m for the foot point positioning, while for multi- Beam spaceborne laser altimeter, when there is an error in the pointing of a certain beam, it may cause a certain systematic error in all beams of the entire system

[0004] At present, the calibration methods of spaceborne laser altimeters for earth observation are mainly single-beam spaceborne laser altimeters, and there is no introduction of on-orbit calibration methods for multi-beam spaceborne laser altimeters

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