2022 - How do GPS/Galileo really work & how the galmon.eu monitors all navigation satellites

media.ccc.de/v...
The whole world depends on Global Navigation Satellite Systems like GPS, Galileo, BeiDou and GLONASS. The technology behind these systems is fascinating and far more interested than generally presented. Although GNSS is super important, up to recently no good monitoring was publicly available. The "galmon.eu" project changed this.
In this talk I cover:
* How your phone really figures out where it is (so it can sell more expensive ads)
* How the "satellite ephemeris" is broadcast, what it means
* What is really in this 'assisted GPS'?
* The extensive ground infrastructure that is active 24/7 to determine the satellite orbits so GNSS is precise enough to tell which store you are in, or which side of the road you are driving on
* How GNSS are monitored in public by 100 Galmon.eu volunteers, running open source receivers all over the world
* And the research we enable
* Discussion of suitable hardware and GNSS-SDR that allows hackers to see each and every bit coming from the satellites
* A brief part on how GNSS can be spoofed and jammed, and the odd cryptography used to help detect or prevent this
The goal of this presentation is to expose the fascinating reality behind that little circle on your maps app, but also to explain how vulnerable this system is, which is why we need to monitor it closely.
The whole world depends on Global Navigation Satellite Systems like GPS, Galileo, BeiDou and GLONASS. The technology behind these systems is fascinating and far more interested than generally presented. Although GNSS is super important, up to recently no good monitoring was publicly available. The "galmon.eu" project changed this.
In this talk I cover:
* How your phone really figures out where it is (so it can sell more expensive ads)
* How the "satellite ephemeris" is broadcast, what it means
* What is really in this 'assisted GPS'?
* The extensive ground infrastructure that is active 24/7 to determine the satellite orbits so GNSS is precise enough to tell which store you are in, or which side of the road you are driving on
* How GNSS are monitored in public by 100 Galmon.eu volunteers, running open source receivers all over the world
* And the research we enable
* Discussion of suitable hardware and GNSS-SDR that allows hackers to see each and every bit coming from the satellites
* A brief part on how GNSS can be spoofed and jammed, and the odd cryptography used to help detect or prevent this
The goal of this presentation is to expose the fascinating reality behind that little circle on your maps app, but also to explain how vulnerable this system is, which is why we need to monitor it closely.
bert hubert
program.mch202...
#mch2022 #MCH2022Curatedcontent

[@robbmaslen]

Bert in terms of a talk borderline perfect, massively technical topic that you made undestandable, you’ve got folks thinking bout fuzzing GPS (what could go wrong :-) ) and appreciation for those unrecognized that pulled the overnighter at xmas. Bloody well done!!

[@ahuopjouwbuis]

Full set of slides: docs.google.com/presentation/d/1I-Ej9TEwihDtfGm2kncBVKV4NtGSTLglukQ4kbClir0/edit#slide=id.g6439467d4d_0_200

[@_TeXoN_]

With modern phones it is really hard to sppof GPS signals. They will get their time via cellphone towers and the ephemeris from the internet. If they don't roughly match the received signal or the received signal is not as stable, your phone won't get a lock. Old receivers might fall for the spoofed signal though.