Initial Results of Calibration and Validation for ALOS Optical Sensors

The advanced land observing satellite (ALOS, the nickname is "Daichi") was successfully launched on January 24^th, 2006. This paper introduces the initial results of calibration and validation for two optical sensors of ALOS i.e., the panchromatic remote-sensing instrument for stereo mapping (PRISM) and the advanced visible and near infrared radiometer type-2 (AVNIR-2). PRISM consists of three panchromatic radiometers, and is used to derive a digital surface model (DSM) with high spatial resolution, which is also an objective of the ALOS mission. The geometric calibration is important in generating a highly accurate DSM by stereo pair image of PRISM. The radiometric calibration is also important for PRISM as well as AVNIR-2. The relative radiometric calibration will be done using acquired images over homogeneous targets such as ocean, deserts, ice and snow areas and the nighttime observation. The absolute radiometric calibration will be carried out by the cross calibration using with calibrated satellite images i.e., MODIS, ASTER etc. In this paper, results of the first images acquisition and initial analysis for calibration and validation are described.