Center For Space Science And Applied Research Chinese Academy Of Sciences

Polarimetric microwave radiometer, a new type remote sensing instrument, can measure all four Stokes polarization parameters of the target's microwave radiation, has good prospects in anisotropic properties of surface roughness and classification and identification of target. Polarimetric microwave radiometer play an important role in ocean wind field measurement and research, it can get all the polarization information by measuring the Stokes vector of the target, what is an effective supplement for the traditional measurement of ocean wind.This dissertation developed a Ka-band analog-based polarimetric microwave radiometer, covering system theory, system design, manufacture and testing of the analog complex correlator, calibration, and analysis of main parameters that represent the performance of polarimetric microwave radiometer.Correlator is the key component of the polarimetric radiometer. This paper presents a direct correlation analog complex correlator associated with advantages such as high sensitivity, small size, low power consumption and so on. The paper give out the error analysis of the analog complex correlator and some suggestions were given to reduce the amplitude error and phase error. According to the results of error analysis, its structure, application, manufacture and performance have also been discussed and their results have been presented. The complex correlator measurement results and the fully polarimetric radiometer noise measurements results have been given out. The results show that fully polarimetric radiometer with an analog correlator has a good performance in polarization measurement. Meanwhile, this paper also presents a additive analog complex correlator, It constitutes a hybrid coupler phase shift network and six detector, the phase of electromagnetic waves will be adjusted to a specific state in IF to access to all the Stokes parameters with the addition thought. The phase shift network were developed both in distribution parameters and lumped, they were measured and compared. The noise test of the additive analog complex correlator is presented at last.In this paper, the calibration theory and hardware technology of polarimetric microwave radiometer were introduced in detail. The calibration standard based on tri-polarimetric calibration theory is presented. Using the theoretical phase relationship of the retardation plate between horizontally and vertically to get the phase shift of the retarder plate. At last, the calibration results of four Stokes parameters were given and the calibration uncertainty and error analysis were given.Finally, the article introduces the important parameters of polarimetric microwave radiometer and presents their Measurement and analysis of results.