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Optimal Estimation Of Calibration Parameters In Polarimetric Microwave Radiometers, David G. Long, Derek Hudson
Optimal Estimation Of Calibration Parameters In Polarimetric Microwave Radiometers, David G. Long, Derek Hudson
Faculty Publications
Methods for internal calibration of a certain class of microwave polarimetric radiometers are presented by Piepmeier. In that work, the calibration parameters are estimated algebraically. We demonstrate that Bayesian estimation decreases the root-mean-square error of the estimates by a factor of two. This improvement is obtained by using knowledge of the noise structure of the measurements and by utilizing all of the information provided by the measurements. Drawbacks are the increased complexity of the method and an increase in computation. We also extend the method to estimate several hardware component parameters of interest in system calibration.
Stokes Antenna Temperatures, David G. Long, Jeffrey R. Piepmeier, Eni G. Njoku
Stokes Antenna Temperatures, David G. Long, Jeffrey R. Piepmeier, Eni G. Njoku
Faculty Publications
The growing importance of polarimetric radiometers has led to the need for a detailed theory for Stokes antenna temperatures. In this paper, we provide a full Stokes vector formulation of an antenna temperature that accounts for the entire antenna pattern, which includes polarization mixing in the main-beam and sidelobe effects. To derive the Stokes antenna temperatures, we follow the conventional methods in the Earth remote sensing literature while relying on a coherency algebra approach from radio astronomy. Connections and parallels to the conventional approaches are noted along the way. We also introduce generalizations of beam efficiency and cross polarization for …