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
18342019012UNUNOREFJan 21, 2019 22:45:00Jan 21, 2019 22:46:0000d:00h:01m:000s
18342019013UNUNOREFJan 22, 2019 22:37:00Jan 22, 2019 22:38:0000d:00h:01m:000s
18342019014UNUNOREFJan 23, 2019 23:41:00Jan 23, 2019 23:42:0000d:00h:01m:000s
18342019016FCSTSUMMJan 24, 2019 14:45:00Jan 24, 2019 22:56:0000d:08h:11m:000s
18342019018UNUNOREFJan 31, 2019 00:04:00Jan 31, 2019 00:05:0000d:00h:01m:000s
21452019019FCSTSUMMJan 31, 2019 07:15:00Jan 31, 2019 12:45:0000d:05h:30m:000s
3692019020UNUNOREFFeb 01, 2019 00:00:00Feb 01, 2019 00:01:0000d:00h:01m:000s
18342019021UNUNOREFFeb 02, 2019 22:52:00Feb 02, 2019 22:54:0000d:00h:02m:000s
26712019023FCSTSUMMFeb 14, 2019 17:45:00Feb 14, 2019 23:22:0000d:05h:37m:000s
18342019024UNUNOREFFeb 18, 2019 06:59:00Feb 18, 2019 07:00:0000d:00h:01m:000s
18342019025UNUNOREFFeb 19, 2019 06:38:00Feb 19, 2019 06:39:0000d:00h:01m:000s

Last checked for outage data: 2019-02-20 09:53:28Z

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.