The ongoing Tropical Rainfall Measuring Mission (TRMM) was launched on November 28, 1997 to monitor and study tropical and subtropical rainfall systems. TRMM standard products (accessible via http://lake.nascom.nasa.gov/data/dataset/TRMM/index.html) are archived and distributed by the Goddard Distributed Active Archive Center (GDAAC). These standard products are stored in the Hierarchical Data Format (HDF), one that is not generally familiar to TRMM users. To address this problem, as well as to broaden the TRMM user base and to expand the potential types of applications of TRMM data, the GDAAC has been engaged in several efforts to develop value-added TRMM products and services. One such effort is to make the capabilities of a Geographical Information System (GIS) available to TRMM users. A GIS is a mapping software combined with a spatial database for analysis of multiple layers of information for a particular geographical location. A GIS would allow users to perform many types of analyses involving TRMM data and both the human and physical geography.

As part of its GIS effort, the GDAAC has begun three initiatives to bridge the gap between TRMM data and GIS tools. The first is the automated conversion of selected TRMM data into GIS-compatible formats, which allows users to bring a TRMM data layer directly into a GIS for analysis. The second is the creation of a WebGIS prototype, which allows users to combine TRMM data with ancillary data to perform mapping and analysis online, using software provided interactively from the GDAAC Web site. TRMM users can thus gain some of the benefits of a GIS for analysis without having to purchase any software. The third initiative is making TRMM data available in formats that are compliant with current, developing interoperability standards. Interoperability allows the seamless integration of compliant geospatial data from local or distributed sources, regardless of the original data format. These initiatives aim to provide TRMM users easier access to analysis tools and emerging technologies that show great potential for enhancing TRMM data analysis. The GDAAC will continue to explore ways to bring the benefits of GIS to the TRMM user and, thus, to help foster new applications of TRMM data.