The first source of validation information are the available local scale vegetation maps. These maps were produced by ongoing projects (i.e. PARN, ECOFAC, WCS, ...) and older projects. Maps from the 70's have also been collected. Some have already been produced through interpretation of satellite data (digital or analogic process) and some have furthermore, been systematically validated through field data information. Other have not (i.e. SPPS, BSP, FAO-SSTC, ...).  Specific reports on Central African vegetation have been collected as well.

The validation process is also based on exchange of information among field partners. In the context of CARPE, the Landsat PATHFINDER project is providing satellite data to support the field activities of its partners (WCS, WWF and BSP). The field partners provide field information and assist in the interpretation of the data.   Fig.3

The Landsat PATHFINDER has a data policy that allows the exchange of satellite data with other projects (i.e. IUCN, ECOFAC, GTZ, ...) and universities in Central Africa . In return, field information is provided. However, the satellite data cannot be used for commercial purpose. 

To support the field activities and the validation of the classification, the Landsat PATHFINDER project is also utilizing the high resolution data purchase facilities of the IGBP-HR DIS project. The acquisition of SPOT data has been programmed at over seven locations in the last two years.

The Landsat PATHFINDER is trying to involve African institutions in the process as much as possible. In-country CARPE partners will benefit from technical support on how to use and apply satellite data to monitor the forests. In addition they will have a facilitated access to PATHFINDER data.  Fig.4  Relations (exchange of data, common field visits, training at the University of Maryland) with the « Service Permanent d'Inventaire Forestier » (SPIAF) of Congo and with the «Centre de Teledetection et de Cartographie Forestiere» CETELCAF of Cameroon have been established since the beginning of the project. New relations are being developed with the « Institut National de Cartographie » (INC) of Gabon and with the «Centre de Recherche Geographique et de Production Cartographique » (CERGEC) of Congo.

Fig.5 

To complete the validation process, field missions are carried out by NASA-UMd experts. In January 1996, a field mission was carried out in Central African Republic and in Cameroon, following the "Route du 4eme parallelle". This mission was a joint-mission with the European TREES Project (TREES-JRC and TREES-SSTC).  Fig. 6 In March 1997, a short survey was carried out in the center of the Gabon Lope area. This field survey was conducted with the help of WCS and the support of ECOFAC. 

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