A Calibration Optical System Based on Geosynchronous Orbit Differential Absorption Spectrometer

Abstract

The invention discloses a calibration optical system based on a geosynchronous orbit differential absorption spectrometer. The swing mirror system consists of a pointing mirror, a swing sweep shaft system, a motor harmonic group, and a U-shaped bracket for the swing mirror. The front optical system is composed of a primary mirror, a secondary mirror, a third reflector, a plane reflector and a slit. The solar diffuse reflector assembly is composed of polytetrafluoroethylene diffuse reflector and corresponding structural parts. The solar shutter assembly includes a sun screen and a motor assembly. The calibration optical system uses the appropriate on-board calibration timing to introduce the bidirectional reflectance distribution function of extra-atmospheric solar illumination whose spectral irradiance is stable and known, so as to accurately measure the diffuse reflection plate and establish an approximate Lambertian surface with known spectral irradiance source, which provides a known radiative input to the remote sensor. The invention has high measurement accuracy, compact volume, light weight and high reliability.

Description

technical field [0001] The invention belongs to the field of optical measurement methods, specifically an optical system based on a geosynchronous orbit that collects and converges sunlight into a spaceborne differential absorption spectrometer for calibration. By introducing sunlight as a calibration light source, the work of the spectrometer is realized. Absolute radiometric calibration on the star with full optical path and full aperture, and long-term monitoring of the stability of the spectrometer on orbit. Background technique [0002] The calibration optical systems of spaceborne and airborne differential absorption spectrometers commonly used at home and abroad basically use the combination of sunlight and diffuser plates. The solar radiation is used as the calibration radiation source to correct the radiation response change of the main optical path; the reference calibration device is used to correct the error caused by the self-decay of the working calibration pla...

AI Technical Summary

Problems solved by technology

This method solves the problem that the on-orbit calibration of the geosynchronous orbit differential absorption spectrometer uses a calibration wheel combined with diffuse transmission, and avoids the problems of the overall volume of the optical system, heavy weight, and reduced reliability.

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