Schriever Air Force Base releases GPS Week Number Rollover guidelines

March 12, 2019  - By

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The 50th Space Wing Public Affairs office of Schriever Air Force Base has established and posted guidelines, known as Interface Specification GPS-200 (IS-GPS-200), for receiver manufacturers to ensure continued capability during the April 6 GPS Week Number Rollover on Coordinated Universal Time derived from GPS devices.

According to the 50th Space Wing, users should be aware of the upcoming GPS Week Number Rollover as it may impact receivers that are not manufactured in compliance with IS-GPS-200 specifications.

The GPS Week Number count began around midnight on Jan. 5, 1980. Since then, the count has been incremented by one each week and years later broadcast as part of the GPS message. One of the GPS week number fields in the legacy navigation message counts from zero to 1,023 weeks. At the completion of every 1,024 GPS weeks, the field rolls from 1,023 to zero and starts counting again.

The first occurrence took place the evening of Aug. 21, 1999, and the message field rolled to zero at midnight GPS time.

The next similar GPS Week Number Rollover is set to take place April 6.

“We appreciate the four billion people around the world who use GPS signals on a daily basis, which is why we are transparent in providing detailed guidance on use for compatibility,” said Lt. Col. Stephen Toth, 2nd Space Operations Squadron commander.

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.

>Read more: GPS Week Number Rollover coming April 6

About the Author: Allison Kral

Allison Kral is the former digital media manager for North Coast Media (NCM). She completed her undergraduate degree at Ohio University where she received a Bachelor of Science in magazine journalism from the E.W. Scripps School of Journalism. She works across a number of digital platforms, which include creating e-newsletters, writing articles and posting across social media sites. She also creates content for NCM's Pit & Quarry magazine, Portable Plants magazine and Geospatial Solutions. Her understanding of the ever-changing digital media world allows her to quickly grasp what a target audience desires and create content that is appealing and relevant for any client across any platform.