Nationwide Differential Global Positioning System

This Notice document was issued by the Research and Innovative Technology Administration (RITA)

For related information, Open Docket Folder

Coast Guard
Research and Innovative Technology Administration
[USCG-2013-0054; RITA-2013-0001]

Nationwide Differential Global Positioning System (NDGPS)


Coast Guard, DHS and Research and Innovative Technology Administration (RITA), DOT.


Notice; request for public comments.


The Coast Guard and the Research and Innovative Technology Administration are analyzing the current and future user needs and requirements of the Nationwide Differential Global Positioning System (NDGPS). The NDGPS was designed to broadcast signals to improve the accuracy and integrity of the Global Positioning System (GPS) derived positions for surface transportation, as well as other civil, commercial, scientific, and homeland security applications. This analysis will be used to support future NDGPS investment decisions by the Department of Homeland Security and the Department of Transportation beyond fiscal year 2016. This notice seeks comments from Federal, state, and local agencies, as well as other interested members of the public regarding current and future usage of the NDGPS, the need to retain the NDGPS, the impact if NDGPS signals were not available, alternatives to the NDGPS, and alternative uses for the existing NDGPS infrastructure.


Comments and related material must reach the Docket Management Facility on or before July 15, 2013.


You may submit comments identified by docket number USCG-2013-0054 or RITA-2013-0001 using any one of the following methods:

(1) Federal eRulemaking Portal:

(2) Fax: 202-493-2251.

(3) Mail: Docket Management Facility (M-30), U.S. Department of Transportation, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.

(4) Hand delivery: Same as mail address above, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The telephone number is 202-366-9329.

To avoid duplication, please use only one of these four methods. See the “Public Participation” portion of the SUPPLEMENTARY INFORMATION section below for instructions on submitting comments.

For Further Information Contact

If you have questions on this notice, contact LT Luke Byrd, Coast Guard, NDGPS Program Manager, telephone 202-372-1547 or email ; or Timothy A. Klein, Research and Innovative Technology Administration, Senior Policy Advisor, telephone 202-366-0075 or email . If you have questions on viewing or submitting material to the docket, call Barbara Hairston, Docket Operations, telephone 202-366-9826.

Supplementary Information

Public Participation

You may submit comments and related material regarding this proposed policy. All comments received will be posted, without change, to and will include any personal information you have provided.

Submitting comments: If you submit a comment, please include the docket number for this notice (USCG-2013-0054 or RITA-2013-0001) and provide a reason for each suggestion or recommendation. You may submit your comments and material online or by fax, mail or hand delivery, but please use only one of these means. We recommend that you include your name and a mailing address, an email address, or a telephone number in the body of your document so that we can contact you if we have questions regarding your submission.

To submit your comment online, go to and use “USCG-2013-0054” or “RITA-2013-0001” as your search term. Locate this notice in the results and click the corresponding “Comment Now” box to submit your comment. If you submit your comments by mail or hand delivery, submit them in an unbound format, no larger than 8½ by 11 inches, suitable for copying and electronic filing. If you submit comments by mail and would like to know that they reached the Facility, please enclose a stamped, self-addressed postcard or envelope.

We will consider all comments and material received during the comment period.

Viewing the comments: To view comments, as well as documents mentioned in this notice as being available in the docket, go to and use “USCG-2013-0054” or “RITA-2013-0001” as your search term. Use the filters on the left side of the page to highlight “Public Submissions” or other document types. If you do not have access to the Internet, you may view the docket online by visiting the Docket Management Facility in Room W12-140 on the ground floor of the Department of Transportation West Building, 1200 New Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Privacy Act: Anyone can search the electronic form of comments received into any of our dockets by the name of the individual submitting the comment (or signing the comment, if submitted on behalf of an association, business, labor union, etc.). You may review a Privacy Act system of records notice regarding our public dockets in the January 17, 2008 issue of the Federal Register (73 FR 3316).

Background and Purpose

The NDGPS augments GPS with an additional differential correction signal. Differential GPS (DGPS) receivers collect transmitted signals from GPS satellites in view, plus the NDGPS correction signals from a nearby NDGPS site. The correction signal improves the accuracy of the GPS position fix.

The NDGPS was developed by the Coast Guard in the 1990s to improve GPS-calculated positions for navigation, for positioning aids to navigation, in support of maritime safety requirements and to offset the error induced by the GPS Selective Availability  (1) function at that time. The Coast Guard's authority to establish, maintain, and operate such aids to navigation is found in 14 U.S.C. 81.

In 1997, the Department of Transportation and Related Agencies Appropriations Act of 1998 (Pub. L. 105-66, section 346 (111 Stat. 1449)) authorized the implementation of the inland component of NDGPS. In 2006, RITA assumed the lead agency role for the inland NDGPS sites.

On August 1, 2007, RITA published a notice in the Federal Register announcing that it was assessing the user needs and systems requirements of the inland (terrestrial) component of the NDGPS (72 FR 42219). On April 18, 2008, based on RITA's assessment, DOT announced its approval of the continuation of inland NDGPS operations.

There are currently 86 NDGPS sites throughout the United States. The Coast Guard funds 49 NDGPS Maritime sites. DOT funds 29 NDGPS Inland sites. The remaining eight NDPGS sites are under the sponsorship of the U.S. Army Corps of Engineers (USACE), and these sites are not addressed in this notice. For more information on the NDGPS, visit the Coast Guard's Web site at . Additional information on the NDGPS is available in the 2012 Federal Radionavigation Plan, published by the Department of Defense, DHS, and DOT. A copy of the 2012 Federal Radionavigation Plan is available for viewing in the public docket for this notice.

DHS, through the Coast Guard, and DOT, through RITA, are analyzing the future requirements for the NDGPS to support investment decisions beyond fiscal year 2016. Future investment decisions may include: maintaining NDGPS as currently configured; decommissioning the entire NDGPS as currently configured; decommissioning a portion of the NDGPS and retaining select sites; or developing alternate uses for the NDGPS infrastructure. Contributing factors to these decisions are: (1) Coast Guard changes in policy to allow aids to navigation (ATON) to be positioned with a GPS receiver using Receiver Autonomous Integrity Monitoring (RAIM); (2) increased use of Wide Area Augmentation System (WAAS) in commercial maritime applications; (3) limited availability of consumer-grade NDGPS receivers; (4) no NDGPS mandatory carriage requirement on any vessel within U.S. territorial waters; (5) the May 1, 2000 Presidential Directive turning off GPS Selective Availability; (6) continuing GPS modernization; and (7) the Federal Railroad Administration's determination that NDGPS is not a requirement for the successful implementation of Positive Train Control.

Request for Comments

This notice seeks comments from Federal, state, and local agencies, as well as other interested members of the public regarding current and future usage of the NDGPS, the need to retain the NDGPS, the impact if NDGPS signals were not available, alternatives to the NDGPS, and alternative uses for the existing NDGPS infrastructure.

We request comments from all interested parties to ensure that we identify the full range and significance of these issues. We specifically request comments regarding the following questions:

(1) To what extent do you use the NDGPS in its current form for positioning, navigation, and timing?

(2) What would be the impact on NDGPS users if the NDGPS were to be discontinued?

(3) If NDGPS were to be discontinued, what alternatives can be used to meet users' positioning, navigation, and timing requirements?

(4) What potential alternative uses exist for the existing NDGPS infrastructure?

After considering all comments, DHS and DOT will inform the public of the agreed course of action with respect to future investment in the NDGPS.


This notice is issued under the authority of 5 U.S.C. 552(a), 14 U.S.C. 81, and 49 U.S.C. 301 (Pub. L. 105-66, section 346).

Dated: April 8, 2013.
Dana Goward,
Director of Marine Transportation Systems, U.S. Coast Guard.
Dated: April 8, 2013.
Gregory D. Winfree,
Deputy Administrator, Research and Innovative Technology Administration.
[FR Doc. 2013-08844 Filed 4-15-13; 8:45 am]


(1)  Initially, high quality GPS signals were only available for military use. GPS signals available for civilian use were intentionally degraded out of concern that civilian GPS signals could be used to guide precision weapons. This degradation feature is known as Selective Availability. On May 1, 2000, President Clinton announced that the United States would stop using the Selective Availability feature. For more information on Selective Availability, visit the Coast Guard's Web site at .

Comment Now!
Due Jul 15 2013, at 11:59 PM ET
ID: RITA-2013-0001-0001
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Document Information

Date Posted: Apr 16, 2013
Federal Register Number: 2013-08844
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Comments Received*
On behalf of the Columbia River Pilot Assoc. I would like to request the DGPS stations 886 Fort Stevens; 871 Appelton; 887 Robinson Point remain intact and...
PUGET SOUND PILOTS are a state regulated private pilotage organization. As such we provide pilotage services for all foreign and domestic vessels transiting...
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* This count refers to the total comment/submissions received on this document, as of 11:59 PM yesterday. Note: Agencies review all submissions, however some agencies may choose to redact, or withhold, certain submissions (or portions thereof) such as those containing private or proprietary information, inappropriate language, or duplicate/near duplicate examples of a mass-mail campaign. This can result in discrepancies between this count and those displayed when conducting searches on the Public Submission document type. For specific information about an agency’s public submission policy, refer to its website or the Federal Register document.

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