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.

PRNSVNNANUTypeOutage startOutage stopDuration
18342019156FCSTUUFNOct 07, 2019 20:00:00Dec 31, 9999 23:59:59Infinity
23602020010FCSTUUFNMar 09, 2020 15:30:00Dec 31, 9999 23:59:59Infinity

Recent Outages

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

PRNSVNNANUTypeOutage startOutage stopDuration
31522020014FCSTSUMMMar 19, 2020 10:49:00Mar 19, 2020 16:45:0000d:05h:56m:000s
18752020015UNUSABLEAug 22, 2019 13:06:00Apr 01, 2020 19:45:00223d:06h:39m:000s

Last checked for outage data: 2020-04-03 11:20:14Z

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.