GPS Satellite Outages

GPS satellite outages are determined by the US Air Force using a Notice Advisory to Navstar Users (NANU). NANUs are categorized by their type and can represent forecasted, current or summary outages. See the full list of outage types on the CelesTrak website.

Current Time

Current Outages

GPS satellite outages identified as current by the US Air Force. Current outage types are usually reserved for unscheduled outages.

There are no current outages at this time.

Predicted Outages

GPS satellite outages identified as predicted by the US Air Force.

There are no predicted outages at this time.

Recent Outages

GPS satellite outages identified as historical by the US Air Force, occurring within the last month.

PRNSVNNANUTypeOutage startOutage stopDuration
29572017091FCSTSUMMAug 22, 2017 20:08:00Aug 22, 2017 22:21:0000d:02h:13m:000s
12582017092FCSTSUMMAug 24, 2017 06:13:00Aug 24, 2017 08:35:0000d:02h:22m:000s
9682017093FCSTSUMMAug 25, 2017 08:47:00Aug 25, 2017 13:58:0000d:05h:11m:000s
21452017094FCSTSUMMAug 29, 2017 17:38:00Aug 29, 2017 20:07:0000d:02h:29m:000s
5502017096FCSTSUMMAug 31, 2017 19:56:00Sep 01, 2017 01:13:0000d:05h:17m:000s
13432017097FCSTSUMMSep 07, 2017 10:50:00Sep 07, 2017 17:57:0000d:07h:07m:000s
7482017100UNUSABLESep 12, 2017 06:25:00Sep 12, 2017 10:07:0000d:03h:42m:000s
1632017103UNUSABLESep 14, 2017 00:21:00Sep 14, 2017 09:26:0000d:09h:05m:000s
7482017104UNUSABLESep 12, 2017 13:42:00Sep 15, 2017 20:09:0003d:06h:27m:000s
25622017106UNUSABLESep 17, 2017 15:00:00Sep 17, 2017 18:13:0000d:03h:13m:000s

Last checked for outage data: 2017-09-22 02:36:37Z

Other links

GPS outages in a calendar format from AGI can be found here:

GPS Satellite Outage Calendar

Historical GPS Outages can be found here:

Historical GPS Satellite Outages

Navigation blog entries

Gps Basics
The basics of how GPS works with some technical content.

How Long Can You Use an Almanac?
GPS position data is contained in almanac files. Learn how long you can use these for analysis.

Selection of my published papers

Operational Considerations for Improved Accuracy with an IOC Galileo Constellation
This paper looks at how the Galileo operators can improve the performance of an initial Galileo constellation by managing their ephemeris and clock errors. Keeping those errors small can help keep initial positioning errors small, even when large DOPs are present.

Long term prediction of GPS accuracy - Understanding the Fundamentals
Topics on prediction methods for GPS and how long GPS errors can be predicted. Starting from an understanding of the elements of prediction, including almanac use and ephemeris and clock errors, I look at the statistics of GPS position error predictions under various scenarios.

Statistical Analysis of Military and Civilian Navigation Error Data Services
This paper examines the difference between ephemeris and clock errors generated using civilian data versus those generated using military data. The different data sources result from civilian GPS receiver and military GPS receiver.