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Anyone has a solution to extenal GPS acquiring satellite through the windshield?

Discussion in 'Model S: User Interface' started by howardc64, Jan 5, 2014.

  1. howardc64

    howardc64 Member

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    #1 howardc64, Jan 5, 2014
    Last edited: Jan 5, 2014
    Don't have tech package so using a 1+ year old Garmin (Nuvi 1450T). The Garmin frequently says it can't locate the satellite. Presumably due to the coating I've heard about on MS's windshield?

    iPhone/Waze doesn't report can't find satellite but would go through short periods of losing your location.

    From a thread on the windshield coating, I see the only place that doesn't block RF is near the rear view mirror so getting an external antenna to this location maybe required

    Coated windshield impacting door openers and EZpass

    Anyone found other solutions? I prefer not setup an external antenna if possible.
     
  2. Chris TX

    Chris TX Active Member

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    Open the moonroof and hold it up? ;)

    Kidding aside, GPS signals have a hard time going through the windshield. There may be an area in the right side section where the rear view mirror is that my DS said has had luck with toll tags. It's the side with a bunch of dots.
     
  3. AmpedRealtor

    AmpedRealtor Active Member

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    If that were true, then my iPhone wouldn't be able to navigate from inside the car. I have no trouble at all.
     
  4. fcharland

    fcharland Member

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    Well unless the gps signal passes through... your roof ;)
     
  5. ecarfan

    ecarfan Well-Known Member

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    The iPhone uses "Assisted GPS" meaning it uses GPS satellite signals AND it triangulates off cell tower locations and known wifi network locations. In areas with decent cell coverage it can provide good nav info just by using cell towers.
     
  6. Chris TX

    Chris TX Active Member

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    ^^^This. Take a look at your iPhone and see if it's getting GPS. Chances are, it's using the cell towers.
     
  7. dbullard

    dbullard Member

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    I also use Waze (playing audio via bluetooth while using the Tesla map display) from my iPhone 5 with no problem.
     
  8. JohnQ

    JohnQ Active Member

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    As another point of reference, I have a Garmin etrex 20 that I use for hiking, biking, etc. It has no problems remaining connected to satellite signals when brought into the car. I've never tried having it acquire a signal while in the car, though.
     
  9. islandbayy

    islandbayy Active Member

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    Get a better GPS??? My 7 year old TomTom One finds satalites within about 2 minutes from turning it on, and does not loose lock. My iPhone also has no problems.
     
  10. AmpedRealtor

    AmpedRealtor Active Member

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    In which case the windshield blocking a GPS signal is not an issue. :)
     
  11. dsmith2189

    dsmith2189 Active Member

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    #11 dsmith2189, Jan 6, 2014
    Last edited: Jan 6, 2014
    I just used the "GPS Test" app on my phone and had the following results. (readings were taken from below the center console)
    Inside a three story H shaped Parking structure with a limited view of the sky I could see 3-4 satellites (weakly, it took about a minute to acquire).
    As I drove to the exit I lost view of the sky and all satellites.
    When I emerged into the open I immediately got strong reception on 15 satellites.

    Now I can turn off my GPS. Hopefully my tin foil hat prevented the spies in the sky from seeing me and scanning my brain.:tongue:
     
  12. Hometheatremaven

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    I don't have the tech package nor a smartphone. I've mounted my older TomTom XL340 to the driver's center air vent and it picks up the satellites within 2-3 minutes. After acquiring signal, it doesn't lose it.
    i think that's pretty good considering the front windshield is coated with AirBlue 80.
    i recently tried a new higher end Garmin GPS, but like my TomTom much better.
     
  13. N4HHE

    N4HHE Member

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    Saturday was a beautiful day for a drive so I took a 130 mile route to the Unclaimed Baggage store in Scottsboro AL. Didn't see anything of much interest until I reached the Last Chance room and picked up a Garmin 50LM and a 760 with matching Garmin cigarette lighter power cables but no mounting brackets, $15 each.

    Both had no problems quickly finding satellites in the center console floor tray thing.

    After further experiments the 760 has a bad battery. But the 50LM really does have a lifetime maps update subscription. Just not enough room to hold all 49 states.
     
  14. howardc64

    howardc64 Member

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    #14 howardc64, Jan 8, 2014
    Last edited: Apr 15, 2014
    Thanks for all the replies. I've googled and see others are having same problems due to the windshield coating.

    My 1+ year old Garmin works well in my other 2 cars (2011 Prius, 2001 Volvo V70XC) but have more problems in the Tesla. I do live in the northwest and have many 4-5 story tall trees in the area. I also wonder if vent mount may be better than windshield mount? (maybe can see better through the side windows without the coating?)

    I'll probably look for GPS signal diagnostic functions on the Garmin and iPhone to get a quantitative difference between the cars and position within the car and report back.

    UPDATE: Tried a Proclip vent mount. Mount is very nice but GPS signal is even worse. Make the GPS nearly useless.
     
  15. mmh

    mmh Member

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    Ugh, I'm having this same problem using both a Garmin 60cx and a Garmin 62stc. Strangely the 60cx does better, but not by much. Never had this problem with any other car.

    Outside the car with a clear view of the sky, the 62stc has a 9ft accuracy radius. Inside the car, signal strength plummets. In the backseat I can get ~35ft accuracy. Anywhere in the front cabin accuracy drops to anywhere around 40ft to 90ft depending how FSM feels.

    Navigation works well enough, but I like to use the GPS to record my drives. Things like distance, time, speeds (min, max, avg), elevation. The poor signal strength results in less logs that are accurate.

    (Coords fudged for privacy)

    Inside Car (note in other cars I get ~12ft)

    IMG_5896.JPG

    Outside Car
    IMG_5898.JPG
     
  16. JPP

    JPP Active Member

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    FWIW, I have a Blackvue dash cam with GPS (to allow the video recordings to be stored with map data, and also record your MPH), and it has major grief getting a GPS lock through the windshield.
     
  17. SUN-day Driver

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    I have an Escort radar detector that uses GPS to silence at locations marked for false alarms (like the "your speed is..." things that blast radar), and to announce the existence of known red light cameras. In the Tesla it's hit or miss whether it can get a GPS signal. It comes in and goes out. I know because it announces "GPS signal lost" and "GPS signal acquired". So I get lots of alarms at places I have previously marked. It works perfectly in other cars.
     
  18. Rebel44

    Rebel44 Member

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    Any reason, why is Tesla using windshield that blocks EM waves like GPS signal?
     
  19. andrewket

    andrewket 2014 S P85DL, 2016 X P90DL (soon 100)

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    Same here, same device. My BlackVue also struggles a bit.
     
  20. Seattle

    Seattle Member

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    It's a side effect of reducing heat and light from the sun. For the same reason many new buildings use windows that have some metallic components that block lots of radio waves, and the sun's energy. The windows screen out light so reduce the amount of needed cooling.
     

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