The contribution of the european space agency to the ALOS PRISM / commissioning phase

The Advanced Land Observing Satellite (ALOS) was launched on Jan 24th, 2006 by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote sensing instruments: Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2), Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) and Phased Array Type L-band Synthetic Aperture Radar (PALSAR). Within the framework of European ALOS Data European Node (ADEN), European Space Research INstitute (ESRIN) as part of European Space Agency (ESA), teamed up with JAXA for contributing to ALOS commissioning phase plan. This paper summarizes the strategy that ESA adopted to define and implement a data verification plan for mission operated by foreign nation, classified as so called ESA Third Party Missions (TPM). The verification of ALOS optical data from PRISM / AVNIR-2 instruments activities had begun four months after satellite launch on March 2007.GAEL Consultant (French company) has supported ESA / ESRIN for designing and executing the plan. A team of principal investigator´s has been put together to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric and image quality assessment. Preliminary results indicate that the radiometric calibration of the AVNIR-2 sensor agrees with Landsat 5 (L5) Thematic Mapper and the MEdium Resolution Imaging Spectrometer (MERIS) calibration to within 10%. The geometry accuracy of PRISM and AVNIR-2 product remains within specifications but some recommendations are provided to improve the quality of product. The preliminary results from the PRISM image quality assessment through computation of PRISM Modulation Transfer Function (MTF) raised few questions toward jpeg compression that degrades image.