National Academies Press: OpenBook

The Global Positioning System: A Shared National Asset (1995)

Chapter: Maritime DGPS Services

« Previous: NOAA Continuously Operated Reference Stations
Suggested Citation:"Maritime DGPS Services." National Research Council. 1995. The Global Positioning System: A Shared National Asset. Washington, DC: The National Academies Press. doi: 10.17226/4920.
Page 172

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

APPENDIX C 172 reference station position. Each reference site would measure coded and codeless L1 and L2 data. This data would then be sent to the CORS Central Facility, where it can be stored on computer disc. Users could then access this data electronically within one hour after it has been measured, providing post-processed positioning accuracy of 5 to 10 centimeters. All Coast Guard, Army Corps of Engineers, and FAA reference stations that are part of the DGPS services described above are designed to be CORS-compatible. In addition, a recent technical report to the Secretary of Transportation has recommended that all future federally provided DGPS reference stations should comply with the CORS standard.55 State and Local Government DGPS A number of state and local governments either have established or plan to establish permanent DGPS reference sites. For example, Riverside County, California, has established two continuously operating, permanent DGPS reference stations as part of the Permanent GPS Geodetic Array. This array, whose participants also include federal agencies, state agencies, other local government agencies, and universities, is used primarily for earthquake monitoring and, perhaps, eventually will be used for earthquake prediction. Riverside County engineers and surveyors, however, also use the array for typical day-to-day surveying applications. Differential Systems Supported by Foreign Governments and International Organizations Foreign governments and public sector international organizations are actively developing and utilizing differential GPS networks. Several examples designed to support aviation, maritime, and survey/scientific applications are discussed below. Maritime DGPS Services Many countries are currently operating, prototyping, or planning maritime DGPS services similar to the U.S. Coast Guard's. The low cost, combined with the absence of any international frequency allocation problems makes these systems practical for all nations. Since most sea coasts and ports have medium-frequency radiobeacons for direction finding, DGPS services can be added quite simply with the purchase and installation of off-the-shelf GPS equipment. The International Association of Lighthouse Authorities (IALA) coordinates the assignment of frequencies and DGPS reference station identifying numbers, 55 U.S. Department of Commerce, National Telecommunications and Information Administration, A Technical Report to the Secretary of Transportation on a National Approach to Augmented GPS Services, NTIA Special Publication 94-30, November 1994.

Next: Inmarsat »
The Global Positioning System: A Shared National Asset Get This Book
Buy Paperback | $61.00 Buy Ebook | $48.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

The Global Positioning System (GPS) is a satellite-based navigation system that was originally designed for the U.S. military. However, the number of civilian GPS users now exceeds the military users, and many commercial markets have emerged. This book identifies technical improvements that would enhance military, civilian, and commercial use of the GPS. Several technical improvements are recommended that could be made to enhance the overall system performance.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook,'s online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!