ALOS-Indonesia POLinSAR Experiment (AIPEX): A Preliminary Result

The successful launched recently of TerraSAR-X (X-Band) on 15 June 2007 marked the start of ´the golden era´ for space-borne SAR in 2007, especially for SAR Polarimetry (PolSAR) and Polarimetric SAR Interferometry (POLinSAR). The first full polarization satellite mission SAR was ALOS/PALSAR (L-Band) which launched on 2006. In addition to these two SAR missions, Radarsat-2 (C-Band) is expected to be launched as scheduled in late 2007, which eventually will complete the availability of three bands (X, C and L) full polarization in separate space-borne SAR missions. This paper update the progress of AIPEX which was selected under JAXA/EORC´s Second Research Announcement. The Experiment applies ALOS/PALSAR imageries which is the first available full polarization SAR in satellite mission. JAXA´s systematic acquisition plan allows Indonesia to apply first L-Band spaceborne polarimetric SAR interferometry (POLinSAR) analysis, from April-May 2007 acquisition. It becomes an important milestone, as the country already had a monumental experience from its first L- and P-Band airborne POLinSAR application in 2004, available through Indonesia Radar Experiment (INDREX) - II, funded by ESA. The recent study of Envisat-Indonesia Radar Biomass Experiment (EIRBEX), under ESA/Envisat AOE-869, has demonstrated the leading role of SAR for a cloudy tropical country such as Indonesia. The availability of Envisat/ASAR dual polarization allowed the first time implementation of a successful SAR polarimetry (PolSAR) analysis in tropical timber plantation forest. This promising result is parallel to the positive result of the previous airborne PolSAR vegetation analysis implemented on NASA´s AirSAR full polarization, multi-frequencies imagery in Indonesia (JPL AirSAR/PacRim-2000). Based on the above milestone results, this Experiment concentrates in the basic studies on scattering and interferometric characteristics, by applying first attempt of space-borne POLinSAR analysis in a consolid- ated four different test sites. These sites are all related to the previous prominent SAR airborne and space-borne campaigns/exercises (Envisat AOE-869, AirSAR PacRIM 2000, and INDREX-II) in Indonesia. The objectives of the study, therefore, will be : (1) to do further studies on scattering and interferometric characteristics by applying first space-borne L-Band POLinSAR analysis; (2) to apply POLinSAR results into CDM/AR, LULUCF sector of the Kyoto Protocol; and (3) to provide feed back to JAXA in relation to suitable EO information product which relevant for Regional Observation mission.