The Tropical Rainfall Measuring Mission (TRMM) is a joint U.S.-Japan satellite mission to monitor tropical and subtropical (40 S - 40 N) precipitation and to estimate its associated latent heating. The TRMM satellite provides the first detailed and comprehensive dataset on the four dimensional distribution of rainfall and latent heating over vastly undersampled tropical and subtropical oceans and continents. The TRMM satellite was launched on November 27, 1997. Data from the TRMM satellite are archived and distributed by the NASA Goddard DAAC.

Despite the relatively short history, the TRMM rainfall products have been widely used in many areas, such as, monitor the recent severe drought in Afghanistan; estimate maize yield potential in SE Asia. To detect climate changes/anomalies, it is necessary to have climate data for comparisons. Willmott et al. applied various techniques to estimate global climate data based on surface observations between 1950 - 1999. Because the observational methods of the surface and satellite products are very different, comparisons are needed to understand existing biases. We are developing a system that will allow users select different rainfall products, an area of interest and a time period and generate graphic (scatter, line, area) output. Application examples will be given.