Synthetic aperture microwave radiometer combined correction method

Abstract

The invention provides a synthetic aperture microwave radiometer combined correction method comprising the steps that (1) the shortest baseline is selected to act as a redundant baseline, and all the related calibration equations are constructed; (2) a few receiver units are selected to act as internal coherent noise injection units, the amplitude and phase error are acquired through a noise injection correction method, and the calibration equations related to the noise injection units are constructed; (3) all the calibration equations of (1) and (2) form simultaneous equations so that a combined calibration equation group based on redundant space and internal coherent noise injection is formed; (4) the constructed combined calibration equation group is solved so that the amplitude and phase error of all the receivers and the out-of-plane displacement angle of an antenna arm are acquired; and (5) the measured visibility function is corrected according to the amplitude and phase error and the out-of-plane displacement angle of the antenna arm which are acquired in the step (4), and the corrected brightness temperature image is acquired by adopting a brightness temperature inversion method.

Description

technical field [0001] The invention belongs to the technical field of microwave remote sensing and detection, and more specifically relates to an error correction method for a synthetic aperture microwave radiometer. Background technique [0002] The synthetic aperture microwave radiometer uses multiple discrete small antennas to synthesize an equivalent large antenna aperture, which is arranged in a sparse array, which reduces the weight and volume of the antenna, and can also improve the spatial resolution of passive microwave remote sensing. But this advantage is at the cost of system structure and signal processing complexity, especially in large synthetic aperture microwave radiometer systems, such as spaceborne synthetic aperture radiometers. [0003] In synthetic aperture microwave radiometers, error correction is an important part to ensure its good performance. At present, there are mainly two error correction methods: 1. Redundant space correction; 2. Internal co...

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Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a combined calibration method for synthetic aperture microwave radiometers based on redundant space and internal coherent noise injection, the purpose of which is to obtain better The error correction effect is better, thus solving the technical problems of poor error correction effect in redundant space correction and greatly increasing the weight and volume of synthetic aperture microwave radiometer in internal coherent noise injection correction

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