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Is that Perth with a great big red blob as well? I don’t think I am misreading the map - what on earth is that? Are the sheep rebelling and have some decent anti-aircraft tech?
https://www.flightradar24.com/data/gps-jamming Also: https://gpsjam.org/ | https://hn.algolia.com/?q=gpsjam (am I missing any other GPS jamming mapping or data collection projects?)
Does anyone know if a similar service covers things like GLONASS, Galileo or BeiDou?
EDIT: nevermind, these services can't distinguish. From the FAQ:
> The ADS-B data used by this map includes information on the accuracy of the navigation system used by each aircraft, but doesn't specify the type of navigation system. It could be GPS, another global navigation satellite system (GNSS) like GLONASS, or it could be an inertial navigation system (INS). My understanding is that most aircraft are using GPS, so that's probably mostly what the map shows.
Earlier quoted context omitted.
Their data comes from commercial flights. If there are no flights, there's no data. There aren't many commercial flights over Ukraine or Belarus right now, so that whole area's empty.
ADS-B is only commercial flights? I thought many kinds of flights are broadcasting. Does Flightradar24 only track commercial flights?
Actually, it's more about airspace:
https://www.aopa.org/go-fly/aircraft-and-ownership/ads-b/whe...
"The FAA requires ADS-B Out capability in the continental United States, in the ADS-B rule airspace designated by FAR 91.225:
Class A, B, and C airspace;
Class E airspace at or above 10,000 feet msl, excluding airspace at and below 2,500 feet agl;
Within 30 nautical miles of a Class B primary airport (the Mode C veil);
Above the ceiling and within the lateral boundaries of Class B or Class C airspace up to 10,000 feet;
Class E airspace over the Gulf of Mexico, at and above 3,000 feet msl, within 12 nm of the U.S. coast."
It's kind of neat how this works: > As part of the ADS-B messages we receive from each aircraft, the Navigation integrity category (NIC) encodes the quality and consistency of navigational data received by the aircraft. The NIC value informs how certain the aircraft is of its position by providing a radius of uncertainty. > Poor NIC values alone might indicate a problem with an aircraft’s equipment or unfavorable pos…
> A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence. Could you use RTLSDR triangulation to hone in on granular lat long of jamming sources? https://www.rtl-sdr.com/detecting-gps-jammers-in-augmented-r... https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-f...
If line of sight to the jamming antenna is required to be jammed, why do aircraft not have a downwards shield so that they only receive GPS signal from the sky (satellites) and not from jammers (coming from the bottom hemisphere)? Or is the jamming signal so many orders of magnitudes stronger than the satellites that there's always going to be some gain no matter how good the shield is? Ok it exists, but shielding is…
- GPS positioning is more accurate if the satellites it sees come from a variety of angles (GDOP), so the satellites near the horizon are valuable.
- Aircraft pitch and roll, so a fixed antenna like this would lose precision as it turns to make an approach - just about the worst possible time.
It's difficult to make an antenna with a sharp cutoff to limit the ground vs. above-ground. So, most anti-jammers will use beamforming to cancel out interference in one or more specific directions. So, the null in the antenna moves to follow the interference.
GDOP: https://en.wikipedia.org/wiki/Dilution_of_precision_(navigat...
Earlier quoted context omitted.
I see 2 red cells on the US/Mexico border right about Texas/Coahuila region. Navigating that dessert region without GPS or with GPS for that matter can be deadly.
That's the most curious jamming I see on the map—anybody know why jamming is present there? Is there a military base in that region?
Earlier quoted context omitted.
> A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence. Could you use RTLSDR triangulation to hone in on granular lat long of jamming sources? https://www.rtl-sdr.com/detecting-gps-jammers-in-augmented-r... https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-f...
You could also use a single receiver with a small antenna array (GPS wavelength is around 20 cm) to estimate the angle of arrival of the incoming signals.
I wonder how the jamming works - is it just for higher altitudes or maybe it only affects GPS and my phone also uses GLONASS or something?
Hey, I'm living in one of these cells in Germany. Hmm.
They are fairly large cells. I assume the “bad” cells are displaying some maxima-based aggregate rather than implying the whole area (or a large part of it) in them is noticeably jammed.