GES DAAC HDF Data Processing and Visualization Tools

The Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC) plays a major role in enabling basic scientific research and providing access to scientific data to the general user community. Several GES DAAC Data Support Teams provide expert assistance to users in accessing data, including information on visualization tools and documentation for data products. To provide easy access to the science data, the data support teams have additionally developed many online and desktop tools for data processing and visualization. This presentation is an overview of major HDF tools implemented at the GES DAAC and aimed at optimizing access to EOS data for the Earth Sciences community. GES DAAC ONLINE TOOLS: MODIS and AIRS on-demand Channel/Variable Subsetter are web-based, on-the-fly/on-demand subsetters that perform channel/variable subsetting and restructuring for Level1B and Level 2 data products. Users can specify criteria to subset data files with desired channels and variables and then download the subsetted file. AIRS QuickLook is a CGI/IDL combo package that allows users to view AIRS/HSB/AMSU Level-1B data online by specifying a channel prior to obtaining data. A global map is also provided along with the image to show geographic coverage of the granule and flight direction of the spacecraft. OASIS (Online data AnalySIS) is an IDL-based HTML/CGI interface for search, selection, and simple analysis of earth science data. It supports binary and GRIB formatted data, such as TOVS, Data Assimilation products, and some NCEP operational products. TRMM Online Analysis System is designed for quick exploration, analyses, and visualization of TRMM Level-3 and other precipitation products. The products consist of the daily (3B42), monthly(3B43), near-real-time (3B42RT), and Willmott's climate data. The system is also designed to be simple and easy to use - users can plot the average or accumulated rainfall over their region of interest for a given time period, or plot the time series of regional rainfall average. WebGIS is an online web software that implements the Open GIS Consortium (OGC) standards for mapping requests and rendering. It allows users access to TRMM, MODIS, SeaWiFS, and AVHRR data from several DAAC map servers, as well as externally served data such as political boundaries, population centers, lakes, rivers, and elevation. GES DAAC DESKTOP TOOLS: HDFLook-MODIS is a new, multifunctional, data processing and visualization tool for Radiometric and Geolocation, Atmosphere, Ocean, and Land MODIS HDF-EOS data. Features include (1) accessing and visualization of all swath (Levels l and 2) MODIS and AIRS products, and gridded (Levels 3 and 4) MODIS products; (2) re-mapping of swath data to world map; (3) geo-projection conversion; (4) interactive and batch mode capabilities; (5) subsetting and multi-granule processing; and (6) data conversion. SIMAP is an IDL-based script that is designed to read and map MODIS Level 1B (L1B) and Level 2 (L2) Ocean and Atmosphere products. It is a non-interactive, command line executed tool. The resulting maps are scaled to physical units (e.g., radiances, concentrations, brightness temperatures) and saved in binary files. TRMM HDF (in C and Fortran), reads in TRMM HDF data files and writes out user-selected SDS arrays and Vdata tables as separate flat binary files.