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Just how accurate is the GPS you ask?

Discussion in 'Photos and Video' started by Suwaneeguy, Sep 21, 2014.

  1. Suwaneeguy

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    https://www.youtube.com/watch?v=0zlodZGY3DM

    Using the google hybrid map, I placed my path line to near the middle of the road.
    Instead, it flew just to the left of that line by a few feet and stayed true.
    I noticed that when I started this time, it showed the bird was 25 feet off the ground.
    Any reason for that?
     
  2. Lithium12.6

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    My Phantom comes back to the same spot within a foot from the distance of 300 meter.
     
  3. witold

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    US government gives you roughly 4 meters accuracy. You can read all sorts of info on this matter on the government GPS website.

    Garmin is the top GPS product company and what do they tell their customers? Here you go: GarminĀ® GPS receivers are accurate to within 15 meters on average. Newer Garmin GPS receivers with WAAS (Wide Area Augmentation System) capability can improve accuracy to less than three meters on average.

    The reason why some devices get really great accuracy is because they don't just use GPS. They use multiple GPS receivers, WAAS, and other signals to improve accuracy.

    I wonder if Phantom GPS module is WAAS-capable...
     
  4. Suwaneeguy

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    Well before GPS, there was a guy in England who had designed his own navigation system and it worked just as good.
    His system involved tracking your location by triangulating radio signals from area radio stations.
    It was jus as accurate as the satellite system.
     
  5. ianwood

    ianwood Taco Wrangler
    Staff Member

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    And we had Loran C in the US which was based on radio triangulation. GPS is way more accurate. Remember that the Phantom accuracy is relative and not absolute unless you are running waypoints. Relative accuracy is always much higher.

    WAAS uses ground stations to measure atmospheric drift. More important for absolute positioning than relative. And altitude is less accurate with GPS. You need 10 or more satellites to get a reasonable vertical fix.