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.
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.
GPS satellite outages identified as predicted by the US Air Force.
There are no predicted outages at this time.
GPS satellite outages identified as historical by the US Air Force, occurring within the last month.
|PRN||SVN||NANU||Type||Outage start||Outage stop||Duration|
|29||57||2017091||FCSTSUMM||Aug 22, 2017 20:08:00||Aug 22, 2017 22:21:00||00d:02h:13m:000s|
|12||58||2017092||FCSTSUMM||Aug 24, 2017 06:13:00||Aug 24, 2017 08:35:00||00d:02h:22m:000s|
|9||68||2017093||FCSTSUMM||Aug 25, 2017 08:47:00||Aug 25, 2017 13:58:00||00d:05h:11m:000s|
|21||45||2017094||FCSTSUMM||Aug 29, 2017 17:38:00||Aug 29, 2017 20:07:00||00d:02h:29m:000s|
|5||50||2017096||FCSTSUMM||Aug 31, 2017 19:56:00||Sep 01, 2017 01:13:00||00d:05h:17m:000s|
|13||43||2017097||FCSTSUMM||Sep 07, 2017 10:50:00||Sep 07, 2017 17:57:00||00d:07h:07m:000s|
|7||48||2017100||UNUSABLE||Sep 12, 2017 06:25:00||Sep 12, 2017 10:07:00||00d:03h:42m:000s|
|1||63||2017103||UNUSABLE||Sep 14, 2017 00:21:00||Sep 14, 2017 09:26:00||00d:09h:05m:000s|
|7||48||2017104||UNUSABLE||Sep 12, 2017 13:42:00||Sep 15, 2017 20:09:00||03d:06h:27m:000s|
|25||62||2017106||UNUSABLE||Sep 17, 2017 15:00:00||Sep 17, 2017 18:13:00||00d:03h:13m:000s|
Last checked for outage data: 2017-09-22 02:36:37Z
GPS outages in a calendar format from AGI can be found here:
Historical GPS Outages can be found here:
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.
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.