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Curious GPS Interference- Possible causes

Discussion in 'General Announcements' started by KB0MNM, Jun 14, 2020.

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  1. KB0MNM

    KB0MNM Ham Member QRZ Page

    Here is a link: www.globalfishingwatch.org/data-blog/circling-above-point-reyes which was called to my attention because of the connection to AIS ( a system that ships use to keep track of positions ) and the changes recently made to allocations in frequency for 5G ( or 4G, LTE? ) communication by the F.C.C.
    Ref:
    https://lnkd.in/gdF-a8C
    c4isrnet.com
    Now there are a few different theories:
    1. Someone having fun sending silly info to the AIS database server ( this sounds pretty far-fetched, because it would require a lot of work to build 'circular tracks' of dis-information ).
    2. Intentional 'spoofing', because at least three of the ships were sailing in waters where the Ukraine government may have had cause to believe that other parties had motive and equipment. Typical equipment might include "GPS Constellation Factory Testers" which can record and/or play back signals used to test new GPS equipment for the ability to reject false signals. Older GPS systems did not include the newer constellations.
    3. Non-intentional 'spoofing' involving harmonics or fundamental overload of GPS receivers by 5G/ 4G LTE base stations, whether or not in 'set-up' ( initial installation ) status.
    4. Poor integration of various systems which contribute to AIS, eg. Satellite and LTE systems.
    5. Other theories ( post 'em here... ) ???
    Yes, this is not amateur radio per se. Yet since many enjoy APRS, it should be of interest to those who follow developments in electronic navigation. One example is DGPS ( Differential GPS ), where reference stations on earth are used for corrections to satellite-based signals.
     
    VE2IHS likes this.
  2. KB0MNM

    KB0MNM Ham Member QRZ Page

    The data-blog link might need to be accessed manually now, starting at the dot org level, then blog. Here is just the start of the article, since a few seem interested:
    By Bjorn Bergman| May 26th, 2020|Data and technology, Data blog
    Analysis from SkyTruth and Global Fishing Watch shows ship tracks jumping thousands of miles from their true locations.

    Bjorn Bergman works with SkyTruth and with the Global Fishing Watch research team to track vessels broadcasting false automatic identification system (AIS) locations and to investigate new sources of satellite data for vessel tracking and for detecting dark targets at sea. In this blog post, Bjorn spots an unusual pattern of false AIS broadcasts concentrated at one location, Point Reyes, northwest of San Francisco on the California coast. Why would vessels thousands of miles away be suddenly popping up in circles over Point Reyes? Could this reflect an intentional disruption of the underlying global positioning system (GPS) that AIS relies on, or is there some other explanation for this pattern?

    In December 2019, SkyTruth reported on a number of locations on the Chinese coast (mostly oil terminals) where ship tracking positions from the automatic identification system (AIS) became scrambled as soon as ships approached within a few miles of a point on shore. Importantly, we knew that this was actual disruption of the underlying GPS system (or more broadly the Global Navigation Satellite System) and not just a shipboard AIS malfunction. We determined this because another source of GPS data, Strava’s heat map of fitness trackers, showed the same ring pattern. A quick recent check of the data showed that this GPS manipulation is ongoing at oil terminals in four of the cities (Shanghai, Dalian, Fuzhou, and Quanzhou) where we had detected it last year. We still don’t know if this manipulation is specifically intended to mask ship traffic or if there is some other reason for disrupting GPS.
     
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    I never did trust GPS, There are to many ways to disrupt it.

    Then we are in a world of hurt. :eek:

    Most anything can be jammed if the signal is strong enough.
     
    K3RW likes this.
  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    The Chinese incidents clearly show a predictable pattern, and IMO is probably deliberate to obscure ship location and movements.

    Gut feel on the Point Reyes incidents is that of probably firmware/software bugs triggered by some less common input or hardware glitch. I can't find anything at your links, so just basing on your description.

    Glad somebody is watching this stuff!!! Wish I could go back to the Navy for a second career as a Cryptologic officer.
     
  5. KB0MNM

    KB0MNM Ham Member QRZ Page

    Some of those links involve access through LinkedIn or Facebook. That is why I copied a bit of the full article. Hindsight is 20/20. In May, the FCC unanimously approved the new authorizations- there are other factors at play here. For one, more sophisticated GPS receivers also include GLONASS constellations- thus reliance on just our (U.S.) system is not always needed- that can be a money issue. As to wishing, be careful what you wish for... I also served to 1985/1987. Thanks for your service. Thanks also to Mr. Steven Bonnell, who posted the info about the F.C.C. ( which seemed to match the AIS query elsewhere ).
     
    KA0HCP likes this.
  6. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    -More specific reply: No reason to assume GPS is the culprit or victim. Again, the problem could be with the AIS units on the ships or perhaps with the AIS report handling system on the internet.

    -The Ukrainian and Chinese port incidents do not seem to be related.

    -Not knowing the true positions of the Ukrainian ships limits ability to analyse. However, taking the Lat/Long of Point Reyes, the antipodal Longitude is roughly 058 East, which at the same Latitude would be in Turkistan, East of the Caspian Sea, which is land locked. Closer to the Black Sea and Mediterranean, where I imagine the Ukraine ships probably are operating.

    -Drawing circles with ship locations is a bit too 'cutesy" for hackers with malignant intentions, requires extra work and is a bit obvious. Attracting attention is not good operations technique.
     
  7. KB0MNM

    KB0MNM Ham Member QRZ Page

    The rest of the article has a table, yet you do not have an e-mail address posted. I have other responsibilities today. Someone posted on the LinkedIn or Facebook website that the courses might be 'faked' at the AIS communications level. This would be VHF, according to that report. Yet Satellite communications and LTE may be involved- because AIS is a system. The problem is that anyone with enough money might be able to defeat one navigation system. Thankfully, not every ship relies on GPS alone. Yet there is a concern for the safety of many ships for economic reasons.
     
  8. KL7KN

    KL7KN Ham Member QRZ Page

  9. KB0MNM

    KB0MNM Ham Member QRZ Page

    When you say Oz, are you referring to "The land down under?" Thanks for the links.
     
  10. K6CLS

    K6CLS Ham Member QRZ Page

    Hi,

    No doubt yhe Chinese are interfering with GPR signals. First noticed a couple years ago by ships at the dock in Shanghai.

    No doubt the Russians were messing with GPS in the North Sea and Black Sea. They won't admit it but US Navy has pretty hard evidence.

    No doubt the US Navy has GPS spoofers. A couple years ago they issued a NOTAM for air users in vicinity of Fallon NV. We detected it all weekend at Black Rock. Spoofing position, but not altitude, from what I could see.

    ... No doubt the some 5G allocations will interfere with all constellations on L band.

    Unless we continue to right it.
     
    K8XG likes this.
  11. KO4LZ

    KO4LZ XML Subscriber QRZ Page

    My company makes (among many other things) vector signal generators that can generate GPS signals. Generally speaking, IQ record and playback of GPS signals only works for testing receiver sensitivity and can't be used for things like position accuracy, time to first fix, resistance to spoofing / jamming, etc. For cases like these, real-time generation of the constellation is required -- i.e. simulate up to dozens of space vehicles that are dynamically moving and whose positions are accurately reflected by almanac / ephemeris data. These systems allow complete control over the constellation, down to the configuration of the individual messages sent by each SV, power levels, fading/multipath, etc. With a modern instrument, you can essentially (re-) create any constellation.

    The topic of spoofing (or anti-spoofing) is probably too long to get into in a single post.

    Here's a fun example of some spoofing a few of our engineers did with one of our instruments:

     
  12. KO4LZ

    KO4LZ XML Subscriber QRZ Page

    I've been personally involved in tracking down GPS interference issues in the field. The most usual cause is ... GPS jammers. The GPS L1 frequency (1575.42 MHz) isn't really harmonically related to any normal high-power signals or cellular signals. The L band doesn't have a lot of high-powered terrestrial transmitters (yet) so fundamental overload is not usually an issue.

    Note however that the 5th harmonic of some key fobs in the United States (315 MHz) can affect GPS, but only at very short distances (a meter or two). On the other hand, the 5th harmonic car remote jammers (yes, they exist), can definitely interfere with GPS signals over a greater distance. I seem to recall an FCC enforcement action against someone who was using a car remote jammer, which was noticed because it was also jamming GPS ... will see if I can find my notes on this later.
     
  13. KO4LZ

    KO4LZ XML Subscriber QRZ Page

    KB0MNM likes this.
  14. K6CLS

    K6CLS Ham Member QRZ Page

    I hope everyone will follow that link and read.

    Those guys got the spectrum for cheap, because no one is really supposed to put any signal in the guard band. They have been trying for mote than 10 years to put something, anything commercial in there. At one point they suggested that crummy unfiltered GPS devices would all have to be replaced, all across the US!

    Shame on the FCC for ever auctioning that spectrum, but double shame on these greedy so n sos for not respecting the terms it came with.

    They won't give up. They just keep trying. Back from the dead at least twice, a bad horror nightmare.

    I am not overstating the threat here.
     
    K8XG and KO4LZ like this.
  15. K6CLS

    K6CLS Ham Member QRZ Page

    Good info, thanks.

    The worrisome reports wete abput spoofing, not jamming. Much more difficult, but potentially devastating consequences.
     

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