Remote Sensing Information Gateway (RSIG)
The Remote Sensing Information Gateway (RSIG) is a tool for selecting, downloading, assembling, and visualizing atmospheric data. After the data has been assembled, it can be stored on the user’s workstation, if desired. RSIG is developed by the US Environmental Protection Agency (EPA).
The RSIG application is operated by selecting from among fifteen or so variables available from the following data sources:
- NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data
- AIRNow data via the AIRNow Gateway
- Air Quality System (AQS) data via the Air Quality Data Mart
- EPA's Community Multiscale Air Quality (CMAQ) model output
- National Environmental Satellite, Data, and Information Service (NESDIS) biomass burning data
- UVNet
More details on RSIG's data sources can be found at http://www.epa.gov/rsig.
The application assembles the data from local files or by submitting requests over the Internet to data repositories at NASA, Sonoma Tech, etc. RSIG then presents a visualization of the data on a latitude-longitude map, automatically locating the data in the correct geographic position.
RSIG uses OGC-WCS-compliant servers/subsetter programs on remote sites such as NASA Goddard to aggregate and subset data files at the source - sending only the specified subset of data (variables, lon-lat box, time-range). Transmission volume over the Internet to the EPA is thereby greatly reduced (by three orders-of-magnitude) compared to the common approach of ftping numerous large files.
RSIG can write the subset of data to your local disk in the following formats:
- Binary External Data Representation (XDR) format (simple, efficient)
- NetCDF-COARDS format
- NetCDF-IOAPI format (regridding the data to a CMAQ grid)
- HDF (unsubsetted satellite files)
- ASCII tab-delimited spreadsheet
- MCMC (used for input into HB model)
- PNG images
- MPG movies
- KMZ movies (for display in Google Earth and similar applications)
Access and Status
The RSIG application is in use and evolving with new features and additional data sources. Users outside the EPA can access the application at http://www.epa.gov/rsig.
Java and Browser Requirements
RSIG has a Web browser-based Java applet for interactive visualization.
RSIG requires Internet Explorer 6 or earlier, or Firefox 3 or earlier.
Note: Internet Explorer 7 cannot run RSIG at this time, due to memory conflicts between IE 7 and the Java Runtime Environment. Until a future version of either IE 7 or JRE resolves these conflicts, we recommend using IE6 or Firefox 3 for running RSIG.
RSIG carries the following Java requirements:
- Java Runtime Environment (JRE)
- Configure Java memory to be larger than the default
- a .java.policy file saved to your Home directory. The .java.policy file is a simple text file that ensures you can save data from the RSIG applet to your computer.
The RSIG web site contains full information on setting-up Java for Linux, UNIX, Mac OS, and Windows systems.
Access to RSIG Data
In addition to the Web browser-based Java applet, RSIG has an OGC-WCS/WMS-compliant web server application to enable streaming access to RSIG's data and images. This can effectively automate access to any data that RSIG can access and deliver the data to your application in various formats. For external users (outside the EPA network) use: http://www.epa.gov/rsig/. Refer to the site's section on "web Access to RSIG Data" for usage examples.
Sponsorship and Contacts
The RSIG application has been sponsored and managed by the EPA Office of Research Development's (ORD) National Exposure Research Lab (NERL). The Principal Investigator is Dr. Jim Szykman. The application is being developed by the EPA's Environmental Modeling and Visualization Laboratory (EMVL).
- Dr. Jim Szykman, james.j.szykman@nasa.gov, EPA ORD (757) 864-2709
- Heidi Paulsen, paulsen.heidi@epa.gov, EPA NCC (919) 541-1834
- For technical support contact the EMVL contract developers:
- Todd Plessel, plessel.todd@epa.gov, (919) 541-5500
- Matt Freeman, freeman.matt@epa.gov, (919) 541-4293
