The Projeto de Monitoramento do Desmatameto (PRODES), led by the National Space Research Institute (INPE), conducts satellites monitoring of deforestation in the Legal Amazon and has been producing annual deforestation rates in the region since 1988, which are used by the Brazilian government for the establishment of public policies. The annual rates are estimated from the deforestation increments identified in each satellite image that covers the Legal Amazon. The data is first released in December of each year as an estimate, which is refined during the first half of the following year.
PRODES uses satellite images of the LANDSAT class (20-30 meters of spatial resolution and 16-day revisit rate) in a combination that seeks to minimize the problem of cloud coverage and ensure consistency. The LANDSAT-5 satellite images were historically the most used by the project, but CBERS-2 and CBERS-2B CCD images, satellites of the Sino-Brazilian remote sensing program, are now widely used. PRODES also made use of LISS-3 images, the Resourcesat-1 Indian satellite, and UK-DMC2 satellite images. With these images, the minimum area mapped by PRODES is 6.25 hectares.
PRODES estimates are considered reliable by national and international scientists (Kintish, 2007), as well as being considered in carbon accounting in the Brazilian Forest Emissions Reference Level for Payments for Reducing Emissions from Deforestation in the Amazon Biome ( FREL-Amazônia).