Calibration and validation plans of ALOS optical sensors

This paper introduces the updated plans for sensor calibration and product validation of the two optical sensors i.e., the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) and the Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2), which are to fly on the Advanced Land Observing Satellite (ALOS). PRISM consists of three panchromatic radiometers, and is used to derive Digital Elevation Models (DEMs) with very high spatial resolution, which is also one of the objectives of the ALOS mission. The geometric calibration is important in generating a highly accurate DEM by using PRISM´s triplet images. Highly accurate ground control points (GCPs) are necessary to calibrate the geometric accuracy and validate the generated DEM. The geometric calibration of AVNIR-2 can be done using the calibrated PRISM product. In this paper, we describe the current plans for calibrating and validating PRISM and AVNIR-2. In particular, preparation status of GCPs with evaluation items for geometric calibration, including expected problem effects regarding geometric accuracy, orbit and observation simulations to determine pointing accuracy, and preliminary investigation of nighttime GCP using current available satellite images