The present invention refers to a method for the radiometric calibration of SAR radar images, i.e. Synthetic Aperture Radar. A synthetic aperture radar system produces a two-dimensional image. A method for radiometric calibration of SAR radar sensors comprises the following steps: 1. selecting from a plurality of images co-recorded by said sensors pixels corresponding to resolution cells on earth comprising targets that maintain the radiometric features unaltered over time, said selecting occurring on a portion of image common to said N images and on the basis of the calculation of a stability index of said radiometric features; 2. estimating calibrating constants, one for each image; 3. using said calibrating constants to compensate each of said images, obtaining compensated images; 4. repeating said estimating by using said compensated images until a convergence is reached, said convergence being defined as a stage of said repeating in which a further repeating does not involve significant variations in the estimation of said calibrating constants.
METHOD FOR RADIOMETRIC CALIBRATION OF SAR SENSORS
MONTI-GUARNIERI, ANDREA VIRGILIO;D'ARIA, DAVIDE;GIUDICI, DAVIDE;ROCCA, FABIO;RIZZOLI, PAOLA;FERRETTI, ALESSANDRO
2008-01-01
Abstract
The present invention refers to a method for the radiometric calibration of SAR radar images, i.e. Synthetic Aperture Radar. A synthetic aperture radar system produces a two-dimensional image. A method for radiometric calibration of SAR radar sensors comprises the following steps: 1. selecting from a plurality of images co-recorded by said sensors pixels corresponding to resolution cells on earth comprising targets that maintain the radiometric features unaltered over time, said selecting occurring on a portion of image common to said N images and on the basis of the calculation of a stability index of said radiometric features; 2. estimating calibrating constants, one for each image; 3. using said calibrating constants to compensate each of said images, obtaining compensated images; 4. repeating said estimating by using said compensated images until a convergence is reached, said convergence being defined as a stage of said repeating in which a further repeating does not involve significant variations in the estimation of said calibrating constants.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
