Tropical Forest Mapping by Radar Remote Sensing: Operational Applications at Global Scale

Large scale and operational applications based on contiguous coverage with SAR data require a set of dedicated techniques in terms of signal handling and product interpretation. The GRFM SAR map of the West African rainforest domain is derived from some 340 JERS-1 SAR images acquired in a time span of 45 days. The original data with a pixel spacing of 12.5 m are spatially compressed by wavelet transform resulting in products representing the estimated cross section as well as textural features at different spatial scales. The SAR mosaic is assembled by projecting the derived products into a compatible map projection. A tentative thematic interpretation is presented at a further reduced pixel spacing. A synoptic view on the vegetation gradients in West Africa is obtained and compared to the TREES map derived from NOAA/AVHRR and the sources of coincidence and divergence are discussed.