Accuracy assessments of standard products of ALOS optical instruments and their high level products

This paper describes the updated results of calibration and validation for optical instruments onboard the Advanced Land Observing Satellite (ALOS, nicknamed "Daichi"), which was successfully launched on January 24th, 2006 and continuously works very well. ALOS has an L-band Synthetic Aperture Radar called PALSAR and two optical instruments 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 that is an objective of the ALOS mission. The geometric calibration is important in generating a precise DSM by stereo pair image of PRISM. AVNIR-2 has four radiometric bands from blue to near infrared and uses for regional environment and disaster monitoring etc . The radiometric calibration is also important for AVNIR-2 as well as PRISM. This paper describes updated results of the radiometric calibration of AVNIR-2, and geolocation determination accuracy evaluation as a part of geometric calibration, and validation of generated DSM by PRISM. These works will be done during the ALOS mission life as operational calibration to keep absolute accuracies of the standard products.