Blog Editor’s Note: BZ (Well Done!) to the US Coast Guard for posting GPS problem reports on the internet for all to see and learn from. Reports from 2018 are available now (we counted 43), new ones will be added, as will reports from previous years. Members of the GPS/PNT community should find this a very interesting page as it already contains an interesting variety of reports. These range from from those clearly due to mapping problems or military exercises, to others with causes that are not at all clear. 

While the Coast Guard seems a bit biased toward citing “user equipment” and away from saying “unknown” for causation, they provide enough information so that readers can intelligently speculate on their own.  A report from a user in Tehran on the 12th of September is a good example.  The user reported being unable to use any GPS applications at all. Since there were no other reports from Tehran (hmmm, wonder why), the says the cause must be in the user’s equipment. Always a possibility, we suppose, though the user reported being unable to access multiple applications (“TD-LTE clock sync, Waze, internet, and other GPS applications) that probably required multiple pieces of equipment, all of which would have had to be faulty. Official jamming in Tehran is common for VIP protection and other state purposes, so some folks might conclude “unknown interference” rather than “user equipment.”  

This new web page is a great educational asset for our whole community. We should all thank the Coast Guard for making the information available.  Particular thanks to the folks at the USCG Navigation Center, its Commanding Officer, CAPT Mike Glander, NAVCEN’s Mr. Rick Hamilton, and Mr. Mike Emerson at Coast Guard Headquarters who leads the Marine Transportation System directorate.  Very, very, well done.


Reports of GPS Problems Submitted by the Public are Now Available on Coast Guard Navigation Center Website

To provide better service and situational awareness to the public, the U.S. Coast Guard Navigation Center (NAVCEN) is now publishing reports of GPS problems on its website. Any notes about problem resolution, if available, will also be listed. The website will be updated as new reports are received and processed. All reports made in 2018 are now available. Reports for prior years will be made available in the future.

Reports of GPS problems submitted to NAVCEN through the GPS Problem Reporting webpage will be posted to the GPS Problem Report Status webpage after review by NAVCEN staff. Reports will be anonymized to protect the submitter’s personal information and any equipment manufacturer data. After user and interagency partner input has been collected, any findings will be added to the report along with the suspected cause and resolution, if available.

The webpage will include the following information for each report:

  • Date / Time of Disruption: Date and time of the report as provided by the reporting source.
  • Date Submitted: Date the report was submitted to NAVCEN.
  • Location: The general location of the reported problem based on input from the reporting source. Latitude and longitude may be used for maritime reports.
  • Type: Installation type as provided by the reporting source. Choices include: Agriculture, automobile, aviation, communications, first responder, marine, law enforcement, research, surveying, timing, transportation, and other (with a fillable field).
  • Description: Description of the problem. This information from the reporting source is edited for clarity and to remove personal and equipment manufacturer identifying details. The description also provides GPS satellite constellation analysis information as provided by the GPS Operations Center, a determination if authorized GPS testing might have been a factor, and information on correlating reports from other users and interagency partners.
  • Cause: The most likely cause of the report based on interagency input.
  • NAVCEN Closed Date: NAVCEN collects interagency input and provides a detailed response to the reporting source for each report submitted. If there are no further questions from the reporting source, and NAVCEN has no other correlating information, NAVCEN will close the case. The results of interagency input will be included in the description field when the case is closed. This date may not correspond to the event end date.

Civil GPS users are encouraged to submit reports of GPS problems to the Coast Guard Navigation Center, civil aviation users are encouraged to report GPS anomalies to the Federal Aviation Administration, and military users should contact the GPS Operations Center.

Rick Hamilton
CGSIC Executive Secretariat
GPS Information Analysis Team Lead
U.S. Coast Guard Navigation Center