Satellite-borne microwave radiometer internal and external calibration system and internal and external calibration method

Abstract

The invention belongs to the technical field of spaceborne microwave radiometer calibration, and particularly relates to a spaceborne microwave radiometer internal and external calibration system, which comprises a microwave radiometer, an internal noise injection module, a GPS occultation signal receiving module, an external occultation module, a periodic self-calibration module and an on-satellite calibration processing module. The microwave radiometer is used for carrying out real-time nonlinear calibration on the calibration reference source by taking seconds as a unit to obtain a primaryobservation brightness temperature value of the observation target; the external occultation module is used for realizing an occultation event according to the received periodic self-calibration temperature occultation signal taking the month as the unit to obtain an external calibration correction value; the periodic self-calibration module is used for switching to a periodic calibration observation mode through a program-controlled lifting mechanism and carrying out periodic observation on the matched load by taking day as a unit to obtain an internal calibration correction value; and the on-satellite calibration processing module is used for performing internal and external calibration correction processing on the primary observation brightness temperature value of the observation target to obtain a corrected observation target brightness temperature value.

Description

technical field [0001] The invention belongs to the technical field of calibration of a space-borne microwave radiometer, and in particular relates to an internal and external calibration system and a method for a space-borne microwave radiometer. Background technique [0002] The microwave hygrometer receiver adopts on-orbit real-time periodic calibration, the low-temperature radiation source is the cosmic cold space background radiation, and the high-temperature radiation source is a microwave-absorbing blackbody. The calibration source is composed of three parts, namely the microwave absorbing black body, the temperature measuring circuit and the shielding cover. The antenna is calibrated once every revolution. The microwave-absorbing blackbody covers the projection aperture of the antenna, and there is a cylindrical shield outside the microwave-absorbing blackbody to eliminate stray radiation from the surrounding environment. However, the setting of the shielding cover ...

AI Technical Summary

Problems solved by technology

However, the setting of the shielding cover increases the volume and weight of the microwave radiometer

[0003] At the same time, since the traditional microwave radiometer on the star does not have a third reference source as a benchmark, the drift cannot be obtained for a long time, and the intergenerational microwave radiometer has a systematic deviation, which changes with the change of the observation target. The correction model has Challenging, bringing uncertainty to long-term climate studies

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