# GPS, Galileo & More: How do they work & what happened during the big outage?

DevFeed: [GPS, Galileo & More: How do they work & what happened during the big outage?](<https://devfeed.tech/articles/gps-galileo-more-how-do-they-work-what-happened-during-the-big-outage-36417.md>)

Original publisher: [Read original article](<https://berthub.eu/articles/posts/gps-gnss-how-do-they-work/>)

Published: 2019-09-30T18:05:33Z

Content type: article

Language: en

Sources: [Bert Hubert's writings](<https://devfeed.tech/sources/bert-hubert-s-writings.md>)

Topics: [navigation](<https://devfeed.tech/topics/navigation.md>), [Monitoring](<https://devfeed.tech/topics/monitoring.md>), [Open Source](<https://devfeed.tech/topics/open-source.md>), [GitHub](<https://devfeed.tech/topics/github.md>), [JSON](<https://devfeed.tech/topics/json.md>)

Tags: [github](<https://devfeed.tech/tags/github.md>), [gnss](<https://devfeed.tech/tags/gnss.md>), [json](<https://devfeed.tech/tags/json.md>), [monitoring](<https://devfeed.tech/tags/monitoring.md>), [navigation](<https://devfeed.tech/tags/navigation.md>), [open-source](<https://devfeed.tech/tags/open-source.md>)

## AI overview

An explanatory article about how GPS, Galileo, GLONASS, and BeiDou navigation satellites determine position. It also documents the Galmon monitoring project, which publicly publishes satellite monitoring results and discusses the 2019 Galileo outage, while noting that the outage section includes the author's speculation.

## Source excerpt

By bert hubert bert@hubertnet.nl / @bert_hu_bert / https://galmon.eu/ Late July 2019, Galileo, "the European GPS" suffered from a week long outage. I'm a proud European, and I think we should have our own well-functioning navigation system, so I tried to figure out what was going on. Surely someone was monitoring this stuff in public? I come from the internet where we monitor all the things, if someone asked for it or not.