The Global Rain Forest Mapping project - a review

The Global Rain Forest Mapping (GRFM) project is an international endeavour led by the National Space Development Agency of Japan (NASDA), with the ai m of producing spatially and temporally contiguous Synthetic Aperture Radar (SAR) data sets over the tropical belt on the Earth by use of the JERS-1 L -band SAR, through the generation of semi-continental, 100 m resolution, im age mosaics. The GRFM project relies on extensive collaboration with the Na tional Aeronautics and Space Administration (NASA), the Joint Research Cent re of the European Commission (JRC) and the Japanese Ministry of Internatio nal Trade and Industry (MITI) for data acquisition, processing, validation and product generation. A science programme is underway in parallel with pr oduct generation. This involves the agencies mentioned above, as well as a large number of international organizations, universities and individuals t o perform field activities and data analysis at different levels. The GRFM project was initiated in 1995 and, through a dedicated data acquis ition policy by NASDA, data acquisitions could be completed within a 1.5-ye ar period, resulting in a spatially and temporally homogeneous coverage to encompass the entire Amazon Basin from the Atlantic to the Pacific; Central America up to the Yucatan Peninsular in Mexico; equatorial Africa from Mad agascar and Kenya in the east to Sierra Leone in the west; and south-east A sia, including Papua New Guinea and northern Australia. Over the Amazon and Congo river basins, the project aimed to provide complete cover at two dif ferent seasons, featuring the basins at high and low water. In total, the G RFM acquisitions comprise some 13 000 SAR scenes, which are currently in th e course of being processed and compiled into image mosaics. In March 1999, SAR mosaics over the Amazon Basin tone out of two seasonal c overages) and equatorial Africa (both seasonal coverages) were completed; t he data are available on CD-ROM and, at a coarser resolution, via the Inter net. Coverage of the second-season Amazon and Central America will be compl eted during 1999, with the south-east Asian data sets following thereafter. All data are being provided free of charge to the international science co mmunity for research and educational purposes.