DOT weighs NDGPS future, asks public input

GPS World, Sept, 2007

The U.S. Department of Transportation's (DOT) Research and Innovative Technology Administration (RITA) is preparing an assessment on the inland component of the Nationwide Differential Global Positioning System (NDGPS) that will determine its future.

As part of that assessment, it is seeking public input from users of the system.

The current expansion of the NDGPS has been placed on hold pending congressional review of the system's funding; RITA's assessment is part of that review. Differential GPS uses the fixed location of a reference station on the ground to improve the positioning resolution provided by civilian GPS satellite signals down to 1-3 meters. NDGPS facilities also monitor GPS satellites for anomalous behavior and issue integrity warnings when necessary.

The NDGPS program is operated jointly with the DOT's Federal Highway Administration, Federal Railroad Administration, and Office of the Secretary of Transportation; the Department of Homeland Security's U.S. Coast Guard; the Department of Commerce's National Geodetic Survey and Forecast Systems Laboratory; and the Department of Defense's Air Force and Army Corps of Engineers. Begun in 1997, to date there are 37 operational NDGPS sites. Two additional sites are ready for construction and could be operational in a matter of months, according to the Coast Guard.

As part of the assessment, RITA published a notice in the Federal Register addressing the current user requirements for the inland or terrestrial component of the NDGPS. This assessment is in preparation for making a recommendation to the National Space-Based Positioning, Navigation and Timing (PNT) Executive Committee, which oversees the entire GPS, on the need to continue to operate inland NDGPS and to make a decision on its future funding.

If no transportation requirements or other federal user requirements are identified as a result of the needs assessment, and if there are no other federal or other funding sources willing to sponsor or partner in sponsoring NDGPS, the DOT will develop a decommissioning plan for NDGPS, according to RITA.

The deadline for public comment is October 1, 2007. Comments may be submitted via the Internet at the Department of Transportation Web site: http://dms.dot.gov/search/document.cfm?documentid=480365&docketid=28836. Instructions for other methods of submitting comments, including via postal service and fax, can also be found there in the docket management portion of the site.