%0 Journal Article
%T Hierarchical Bayesian Data Analysis in Radiometric SAR System Calibration: A Case Study on Transponder Calibration with RADARSAT-2 Data
%A Bj£¿rn J. D£¿ring
%A Kersten Schmidt
%A Matthias Jirousek
%A Daniel Rudolf
%A Jens Reimann
%A Sebastian Raab
%A John Walter Antony
%A Marco Schwerdt
%J Remote Sensing
%D 2013
%I MDPI AG
%R 10.3390/rs5126667
%X A synthetic aperture radar (SAR) system requires external absolute calibration so that radiometric measurements can be exploited in numerous scientific and commercial applications. Besides estimating a calibration factor, metrological standards also demand the derivation of a respective calibration uncertainty. This uncertainty is currently not systematically determined. Here for the first time it is proposed to use hierarchical modeling and Bayesian statistics as a consistent method for handling and analyzing the hierarchical data typically acquired during external calibration campaigns. Through the use of Markov chain Monte Carlo simulations, a joint posterior probability can be conveniently derived from measurement data despite the necessary grouping of data samples. The applicability of the method is demonstrated through a case study: The radar reflectivity of DLR¡¯s new C-band Kalibri transponder is derived through a series of RADARSAT-2 acquisitions and a comparison with reference point targets (corner reflectors). The systematic derivation of calibration uncertainties is seen as an important step toward traceable radiometric calibration of synthetic aperture radars.
%K synthetic aperture radar
%K radiometric calibration
%K external calibration
%K Bayesian data analysis
%K transponder
%U http://www.mdpi.com/2072-4292/5/12/6667