Fusion of the L-band GRFM and C-band CAMP wide area Central Africa radar mosaics: a new data set with unprecedented potential for regional scale vegetation mapping

A new data set has been compiled by combining two wide area SAR mosaics over Central Africa: the L-band JERS-1 Africa mosaic, generated in the context of the NADSA Global Rain Forest Mapping project (GRFM); the C-band ESA ERS mosaic, developed by the JRC Central Africa Mosaic project (CAMP). The GRFM Africa mosaic was geolocated using a block adjustment algorithm which assures an internal geometric consistency at sub-pixel accuracy and an absolute geolocation residual mean squared error of 240 m with respect to ground control points. The projection used is a direct Mercator. The GRFM data set was therefore taken as the reference system and the C-band ERS layer composed by rectifying each ERS frame, after down sampling at 100 m pixel spacing, to the reference mosaic. Each mosaic consists of multiple features (amplitude and texture measures), and acquisitions at two dates; the resulting data set is therefore multi-temporal, multifeature, and multi-frequency. Clearly such a data set presents novel features, and an unprecedented potential for vegetation mapping at regional scale. As an indication, a test case is discussed related to the visual interpretation of the main vegetation types in the Congo river floodplain.