Calibration and Validation Concept for the Airborne PRISM Experiment (APEX), Canadian Journal of Remote Sensing

The development of the Airborne PRISM Experiment (APEX) is supported by the European Space Agency (ESA) in view of an appropriate data simulator for future spa-ceborne hyperspectral instruments of the Agency. The terminology and conceptual design of the calibration and validation steps required for the APEX system are defined in this paper. The calibration concept for the APEX instrument is based on a standardized labo-ratory procedure in which spectral response, geometric response, as well as radiometric gain and offset values are determined. Additionally, in-flight calibration using sensor-in-ternal means and vicarious calibration approaches will improve the reliability of the cali-brated image data. All calibration-related parameters as well as the image data are kept and administered by the APEX Processing and Archiving Facility (PAF). A processing chain is defined which allows an efficient preparation of all the calibration parameters and fully reproducible processing of the acquired data from raw format to calibrated radiances. The validation concept for the imagery and its processing is based on sensor simulation, standard quality control procedures, and in-flight validation campaigns. The combination of all these efforts results in a consistent characterization of the APEX instrument perfor-mance and a reliable quality definition of the final image data products. page