Nonlinear calibrating method and device for foundation microwave radiometer

Abstract

The invention provides a nonlinear calibrating method for a foundation microwave radiometer, and the nonlinear calibrating method can be used for realizing noise injected multi-point brightness temperature on the basis of foundation microwave radiometer noise injected two-point calibration. In the method, periodical calibration is performed on drifting of noise temperature and gain of a receiver by utilizing multi-point brightness temperature values which are acquired by two known reference targets and the other two known noise injected reference targets, and a calibration equation acquired by nonlinear factors of a foundation microwave radiometer system can be determined for real-time measurement of the target brightness temperature. Meanwhile, the invention also provides a nonlinear calibrating device for the foundation microwave radiometer, and the nonlinear calibrating device comprises a noise injection module and a system built-in calibration blackbody, wherein the noise injection module comprises a noise source, a switch and a directional coupler; and the system built-in calibration blackbody provides standard brightness temperature equivalent to the environment temperature. By utilizing the method, nonlinear errors caused by the nonlinear power characters of a detector diode can be reduced, so that the detection accuracy can be improved.

Description

technical field [0001] The invention relates to a calibration device and a method thereof, in particular to a nonlinear calibration method and device for a ground-based microwave and millimeter wave radiometer. Background technique [0002] The microwave radiometer is a passive microwave remote sensor that can penetrate clouds and rain areas, and can penetrate the surface or vegetation at a certain depth to obtain ground information covered by vegetation and target information at a certain depth below the surface. Timely and all-weather observation of global atmospheric temperature and humidity, water vapor content, rainfall and other space weather data, as well as geological and resource surveys, marine environment and sea state detection, disastrous weather forecast and detection, etc., play an important role in atmospheric detection and ocean observation effect. From a broad perspective, microwave radiometers are mainly used in atmospheric microwave remote sensing, ocean...

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is, in order to overcome the problem that the above-mentioned multi-channel ground-based microwave radiometer system device cannot determine the nonlinear characteristics of the system caused by the detection diode before leaving the factory, thereby proposing a calibration method and device for the microwave radiometer

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