Processing of SRTM data will take about 2 years to complete. The timeline above gives an overall view of the activities over that time period.

Copying the SRTM Data Tapes
The first activity is the copying of the flight data tapes. There are 208 C-radar data tapes containing over 7 terabytes of raw data. These invaluable tapes will be held at the Kennedy Space Center in climate-controlled safes. The copying will be done at KSC by a team of engineers from JPL. Because the tapes will be duplicated at 1/6 speed, it is expected to take up to 2 months to copy all the tapes. Two copies will be made, then the copies will be transported to JPL, one batch at a time, for processing. The X-SAR data will be processed in Munich by the German Space Agency.

The SRTM Processing Software
The software for the Ground Data Processing System (GDPS) has been under development for some time by the Algorithm Development and Verification (ADV) team. The system is broken into 3 parts: Interferometric processor, which converts the raw radar data into a height map and radar image strips; Mosaic processor, which takes the myriad of strips from all over the world and compiles a mosaic of the height and image data a continent at a time; and the Verification system, which tests the mosaics for quality, producing an accuracy map. The processors have been operating on workstations at JPL; the next job is to install them on a set of supercomputers for systematic processing of the full SRTM data set. While this is going on, JPL will release additional products to the public, as we did during the flight. We also plan to release a sample DEM and orthorectified radar image as soon as we obtain the reformatted flight files and calibrate our workstation processors.

Processing the SRTM Data
After the GDPS has been set up and tested, systematic processing will begin. The SRTM data will be processed on a continent-by-continent basis, with priorities given by NIMA. As the continents are finished, the data will be sent to NIMA for final data quality checking. After that step, copies will be sent to the US Geological Survey's EROS Data Center (EDC) for archive and distribution to the public. NIMA will reformat the data into their own DTED format and handle archive and distribution to the DoD.

Archiving the SRTM Data
At the end of systematic processing, the full SRTM data set, including ancillary data, will be archived at EDC.

Formats and Distribution of the SRTM Data
Discussions are continuing with the USGS on formats, cost, and mode of distribution. At this time, it appears that the formats of the data will be similar to other data distributed by EDC. The Digital Elevation Model (DEM) will probably be the same as their 7.5' DEM (see below for more information), while the radar image mosaics will probably be simple byte raster data, such as Landsat and other remote sensing image data sets. Costs will probably be limited to the cost of fulfilling the request and will be determined later by EDC. With the common use of the internet, FTP will undoubtedly be one method of distribution. CD-ROM and DVD may also be used. More details of the EDC's methods of data distribution may be found at their web site.

Data Similar to the SRTM DEMs
If you're interested in data similar to SRTM's DEMs, the USGS EROS Data Center is the place to visit. The first two data sets listed below are very similar to the resolution and quality of the full-resolution SRTM DEMs.

National Elevation Dataset (NED)
- seamless, "best available" USGS elevation data
- resolution: 1 arc second (approximately 30 meters); Alaska: 2 arc seconds
- coverage: United States (including Alaska and Hawaii)
- Web site: http://gisdata.usgs.gov/ned/

7.5-minute (1:24,000-scale) DEMs
- 7.5-minute tiles
- resolution: 30 meters; some at 10 meters
- coverage: conterminous United States, Hawaii, Puerto Rico
- Web site: http://edc.usgs.gov/doc/edchome/ndcdb/7_min_dem/states.html

15-minute (1:63,360-scale) DEMs
- 15-minute tiles
- resolution: 2 by 3 arc seconds (approximately 60 meters)
- coverage: Alaska
- Web site: http://agdc.usgs.gov/data/usgs/geodata/dem/63K/dem63k.html

1-degree (1:250,000-scale) DEMs
- 1-degree tiles
- resolution: 3 arc seconds (approximately 90 meters)
- coverage: United States (including Alaska and Hawaii), Puerto Rico
- Web site: http://edc.usgs.gov/glis/hyper/guide/1_dgr_demfig/states.html

GTOPO30
- seamless, "best available" public domain elevation data
- resolution: 30 arc seconds (approximately 1 kilometer)
- coverage: global
- Web site: http://edcdaac.usgs.gov/gtopo30/gtopo30.html