Pan-tropical Forest Cover Mapped with Cloud-Free Radar Imaging

The Woods Hole Research Center has produced a pan-tropical database of high-resolution ALOS/PALSAR data for use in mapping of pan-tropical forest cover and associated carbon stocks stored in above-ground biomass and for supplying baseline data for subsequent deforestation and forest degradation monitoring across the forested tropics of Central Africa, Latin America and Southeast Asia. Radar images from the Japanese ALOS satellite-borne PALSAR sensor have been collected since successful launch by the Japan Aerospace Exploration Agency (JAXA) in 2006. The sensor is cloud penetrating due to the use of long wavelength (23 cm, L-Band) for imaging of Earth's surfaces. As part of a systematic observation strategy for global mapping, cloud-free, pan-tropical data sets of PALSAR radar data are acquired within a couple of months every year. The first near-complete collection of pan-tropical data in a dual-polarimetric mode, which proves very useful for forest mapping, was achieved in June-September 2007, with some minor acquisition gaps filled during 2008 and 2009 observations cycles. Work is ongoing to classify the pan-tropical ALOS image mosaic data into forest cover information.