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    Re: GPS spoofing for real
    From: Frank Reed
    Date: 2017 Aug 12, 14:18 -0700

    I'm puzzled by this story... and skeptical. I think it's possible that this is a well-choreographed hoax or simply an originally small story of an unknown anomaly that has been embelished by people who have their own vested interest in suggesting GPS spoofing. 

    There is some small evidence here, yes, but where is the rest of the story? The city of Novorossiysk has a population of about 250,000. That implies over 100,000 smartphones, and nearly all of those would be GPS and GLONASS capable. Where are the reports of erroneous positions on these dates from those users? Even if just 1% complained on social media (e.g.), there should be around a thousand reports of bizarre positioning data emerging from Novorossiysk. There is the possibility, of course, that there was a spoofing system targeting only vessels offshore from the port, but I find that very hard to believe. The articles also mention the possibility of seeing multiple vessels shifted over 30 km from their true positions in standard AIS data sources. That's true. That would be substantial and interesting evidence. Where is it? Also where are the other GPS receivers on the un-named vessel in this story? We have a photo of the display of a GPS position from the main nav system on some vessel . Where are the screen caps from the smartphones which were, without doubt, present in substantial numbers aboard this vessel? Not even one was turned on to compare its GPS position with the main nav system?? That's hard to believe.

    By the way, Gary mentioned the risk to aviation, especially aircraft in the immediate vicinity of the airport. This is a real risk, but the solution here is simple if, as appears to be the case, a GPS-spoofing system affects all GPS systems in the immediate vicinity. To manage this risk, you install an app on every air traffic controller's smartphone that detects the GPS position and compares it with the observer's known, fixed location. Do this ten times a minute, and if the GPS position moves from the known position by more than some pre-assigned minimum, like 20 meters maybe, then the app issues an alert. In fact, of course, something very much like this already exists: this is the essence of DGPS which transmits the position difference between the GPS solution off the air and the known positions of a network of ground stations. Can you spoof a DGPS system? I don't see how. Whatever offset is fed into the spoofed signal will be automatically detected and included in the local offset. Of course if that offset is large enough, it may overflow some system limits (a DGPS reporting station might have no problem with offsets up to 100 or even 200 meters, but it might well crash if the offset exceeds, let's say, 10km). That, however, is a small and manageable problem.

    GPS spoofing is a real threat if not now, then soon.  Unfortunately this threat is being abused by interests who advocate so-called "eLoran", a Luddite solution but one with potentially huge contracts behind it. In fact, the best alternative to satellite navigation is satellite navigation ...of a different type. As we chat, experiments on this front involving constellation of LEO satellites are already underway. While the technologically incompetent idiots in the US House are busy voting untold millions for a neo-"Make America Stupid Again"-Loran, alternatives are already being put in place. But hey, why not feed at the trough while the fools are throwing money around, right?

    Frank Reed
    Conanicut Island USA

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