Recent Progress in In-Flight Radiometric Calibration and Validation of the RapidEye Constellation of 5 Multispectral Remote Sensing Satellites

BlackBridge AG is a geospatial data provider which operates a constellation of five identical multispectral remote sensing satellites. These satellites cover five spectral bands in the visible VIS and near infrared NIR spectral range. Radiometric calibration of multispectral and hyperspectral instruments like those operated by BlackBridge AG is of fundamental importance if the data e.g. should be used for remote sensing applications or if the atmospheric influence to the data should be corrected using methods based on atmospheric transfer codes. For the RapidEye constellation three goals are achieved using calibration. First, spatial calibration corrects response differences for the individual CCD elements in one CCD array. Second, temporal calibration provides a comparable measurement of the five different cameras over time. Finally, absolute calibration links the relative digital number DN outputs of the sensors to absolute at-sensor radiance levels. This paper explains in detail the methodologies used for radiometric calibration of the five satellite constellation.