High resolution DSM generation from ALOS PRISM data - pre-launch simulation and assessment plans

The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise land coverage observation, disaster monitoring, and resource surveying and will be launched in 2005. The Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) carried at ALOS satellite is expected to generate worldwide Digital Maps in respects of its high resolution and stereoscopic observation. The development and evaluation of the software for generating digital surface model (DSM), based on this aim of ALOS operation, is now undertaking for the purpose of equipping the system which producing DSM semi-routinely in the Earth Observation Research and Application Center (EORC). In this paper, the statuses of pre-launch simulations and DSM assessment plans are described. PRISM consists of three panchromatic radiometers for forward, nadir, and backward views and acquires each image in the same orbit at almost the same time. It enables to generate more precision DSM frequently than usual stereoscopic observations. For this specific stereo image configuration, the triplet images matching algorithm is applied for the DSM generation. To evaluate the algorithm, three line scanner (TLS) data is used as the PRISM simulation data. The DSM generation using the JERS-1 OPS stereo images is being performed as the operational simulation. The basic functions of the software such as bundle adjustment, DSM mosaic, mask operation, etc. are evaluated in those simulations. The accuracy assessment of generated DSM is planned to be performed using the LIDAR DSM data, SRTM data, GCP etc.