GPS Satellite Outages

GPS satellite outages are determined by the US Space 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.

These satellite outages are retrieved via a REST API from OneSky. Contact me to get an API key to try these and other technical web services yourself.

Current Time

Current Outages

GPS satellite outages identified as current by the US Space 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 Space Force.

PRNSVNNANUTypeOutage startOutage stopDuration
5502022058FCSTDVSep 29, 2022 22:30:00Sep 30, 2022 10:30:0000d:12h:00m:000s

Recent Outages

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

PRNSVNNANUTypeOutage startOutage stopDuration
26712022048FCSTSUMMSep 08, 2022 12:29:00Sep 08, 2022 17:57:0000d:05h:28m:000s
30642022051UNUSABLESep 14, 2022 20:03:00Sep 14, 2022 22:33:0000d:02h:30m:000s
23762022055UNUSABLESep 08, 2022 06:51:00Sep 16, 2022 15:28:0008d:08h:37m:000s
6672022057FCSTSUMMSep 22, 2022 15:01:00Sep 22, 2022 20:41:0000d:05h:40m:000s

Last checked for outage data: 2022-10-05 20:51:12Z

Historical GPS Satellite Outages

Satellite Outage File Inconsistencies

ICD-GPS-240C defines the Satellite Outage File fields in Section 30: Appendix 3. In that section, specific NANU types are associated with specific Satellite Outage File states; Historical, Predicted and Current. In the currently published satellite outage files, there is a NANU type that is not covered: FCSTUUFN. This NANU type is defined in the ICD, but not covered by the SOF definition in Appendix 3, so there is no ICD controlled way to add this outage type to the SOF.

The satellite outages in the OneSky services used to display the data on this page have been modified to account for these inconsistencies, over those outages you'll see in the currently published raw Satellite Outage Files.

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

Quantitative Analytics for BVLOS Operational Risk Assessments
Using quantitative analytics, we show that functions describing metrics of interest in BVLOS ORAs can be used to define risk likelihood. This leads to a way to automate operational risk assessments, and visually display risk likelihood for faster, more accurate UAV operator decision making.

Understanding GPS Navigation in Contested Environments
Review of GPS errors, their source and how we can mitigate them. Review of terrain datums and their operational usage and an overview of alternative navigation techniques.

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.