Step-by-step calibration system and method applied to microwave radiometer of unmanned airborne phased array antenna

Abstract

The invention discloses a step-by-step calibration system and method applied to a microwave radiometer of an unmanned airborne phased array antenna. The system comprise a noise diode, matching loads,a power divider and calibration switches, wherein the number n of the calibration switches is consistent with the number of subarrays of the phased array antenna; the calibration switches are single-pole three-throw switches; one path of input of each calibration switch is connected with one path of H polarization signal output by each subarray of the antenna; the noise diode provides a high-temperature signal needed for calibration, and n paths of signals are output to one input of input of each calibration switch through the power divider; each calibration switch is externally connected witha matched load, and a normal-temperature reference signal needed for two-point calibration is provided; three states of each calibration switch correspond to ground observation, high-temperature noise source observation and matching load observation respectively; and during operation, a beam control device controls the calibration switches to be switched according to a predesigned time sequence,and the ground observation and the two-point real-time calibration of different subarrays are completed within each scanning period.

Description

technical field [0001] The invention designs a calibration method for a phased array antenna microwave radiometer, and belongs to the technical field of space microwave remote sensing. Background technique [0002] The step-by-step calibration method of the phased array antenna microwave radiometer on the UAV provides support for the phased array antenna system microwave radiometer to obtain high calibration performance, and realizes the inversion of the system to generate seawater salinity, sea surface temperature and sea surface wind speed, etc. The basic parameters of the ocean provide guarantee, so that the system can meet the application requirements of real-time detection of my country's offshore environment, and provide important environmental information guarantee for maritime economic activities. [0003] The existing airborne radiometer calibration methods all use the traditional overall noise injection single-point calibration method, which can obtain a single cali...

AI Technical Summary

Problems solved by technology

[0003] The existing airborne radiometer calibration methods all use the traditional overall noise injection single-point calibration method, which can obtain a single calibration parameter. Under the phased array antenna system, it is impossible to correct the calibration error between the antenna arrays. To obtain high-precision calibration performance; does not have the flight real-time two-point calibration function, the calibration is highly dependent on the stability of the receiving channel and platform environment, and cannot obtain high calibration performance in real time; does not have the cross-calibration function with satellites

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