CIESIN Thematic Guides The Tropical REsources and Environment monitoring by Satellite (TREES) Project is being conducted jointly by the Commission of the European Communities (CEC) and the European Space Agency (ESA). Malingreau et al. (1993) describe the project in the paper "AVHRR for Global Tropical Forest Monitoring." The project involves development of space observation techniques for monitoring the tropical forests of the world. An operational objective of the project is to perform a global tropical forest inventory and deforestation study using complete coverage with Advanced Very High Resolution Radiometer (AVHRR) 1-km maximum Normalized Difference Vegetation Index (NDVI) composited data sets, supplemented with high resolution Landsat Thematic Mapper (TM) and Systeme Probatoire d'Observation de la Terra (SPOT) satellite image data. Information about the availability of the composited data sets can be requested from the TREES AVHRR contact.