Preliminary study on data sets of ADEOS-II and ALOS dedicated to terrestrial carbon observation Original Research Article

Global carbon observations is a fundamental requirement in the context of the Terrestrial Carbon Observation (TCO) theme within the Integrated Global Carbon Observation (IGCO) theme of Integrated Global Observation Strategy Partners (IGOS-P), for quantitative estimation of key biophysical parameters such as net primary productivity (NPP), carbon stocks and their changes in time. In support to this major international effort, NASDA, through its Earth Observation Research Center (EORC), is planning global systematic data observations using the Phased-Array L-band Synthetic Aperture Radar (PALSAR) onboard the Advanced Land Observing Satellite (ALOS) from 2004. Like its predecessor - the JERS-1 SAR - the PALSAR instrument will operate in the longer L-band wavelength range (23.5 cm), with added polarimetric features making it attractive for assessment of regenerating and lower-density above-ground biomass, and changes therein. In addition to ALOS, the Global Imager (GLI) instrument onboard the Advanced Earth Observing Satellite-II (ADEOS-II), launched successfully in December 2002, will be used to estimate annual change of global NPP at 1 km and 250 m spatial resolutions. Notable is that the six terrestrial channels on GLI operate with the same wavelength as Landsat ETM+ and MODIS, but all with a spatial resolution of 250 m. This paper describes the preliminary study on the applicability and improvement of data sets from PALSAR on ALOS and GLI on ADEOS-11 for terrestrial carbon observation.