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iPhone and True North

Discussion in 'Pro/Adv Discussion' started by marzipana, Jan 12, 2016.

  1. marzipana

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    Anyone here using an iPhone with their Phantom? With your phone's compass, do you have True North selected in the Settings of the phone, or should it be off?
     
  2. msinger

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    Mine is turned off.
     
  3. Jeff48920

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    This is interesting. I have 150 flights on my P3P and just short of 1,000,000 feet and I have always had my True North turned on both my iPhone 6 and my iPad Mini 2.

    I have no idea of whether our devices should be using true north or magnetic north.
    Here's an article about the use of true or magnetic.

    Using True North vs. Magnetic North


    I do wonder what North the Phantom is aligning to after the compass dance and whether our devices should use the same North.
     
  4. Jeff48920

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    Here's another interesting quote

    Go for the true north, a.k.a. the geographic north. It will make things easier ... unless you are a pilot.

    The magnetic north is somewhere in Canada and moves all the time. The difference between the two is called, the magnetic declination. Since the magnetic north moves, the yearly correction that must be added or subtracted is called, the magnetic variation.

    Where I live, in Norway, the magnetic declination is nearly null, but at some other places on earth, it can be as much as 30 degrees so it is better, and easier, to keep your compass to the true (geographic) north.

    But what about aviation and pilots? Well, all bearings, headings and marking for aviation are given in magnetic north notations. For example the runway 24 is 240 degrees magnetic north. This is because the magnetic compass is still the primary instrument for pilots and, contrary to seafarers who have time to compute the true north of a chart table, the pilot must take quick decisions.

    By the way, you will read in some places that the difference between the magnetic and geographic north is called the magnetic variation. That is not true. It is mostly pilots who call it that. It comes from the fact that seafarers use old charts where it is written in the margin, the magnetic declination for the year of publication, then the annual variation. But pilots use new charts all the time. The time between two chart update is actually called, an AIRAC and it happens, internationally, every 28 days!
     
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  5. ianwood

    ianwood Taco Wrangler
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    As Jeff pointed out above, the difference between magnetic and true north is what is called magnetic declination. We dealt with this a lot on the P2 as it originally didn't correct for it which caused all sorts of issues especially for those in areas of high declination.

    The P3 adapts magnetic north to true north. All GPS based navigation needs to done against true north as GPS has no concept of magnetic variation.

    If you want to read more about it, it is covered in the calibration primer here: Compass Calibration, A Complete Primer | DJI Phantom Forum
     
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  6. RoyVa

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    I don't believe you craft is flying by your phones compass. It has its own and uses the google maps and GPS cordinances for location and flying and uses its on compass for the earths magnetic deviation at your location. That why you need to re calibrate the compass if you travel 50-100 + miles away due to the earths magnetic field changes.
     
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  7. ianwood

    ianwood Taco Wrangler
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    This is correct. Your phone's compass is not used for the P3's navigation. It has its own compass.
     
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  8. alokbhargava

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    Radar on the phone uses its compass to show alignment.
     
  9. Helijoc

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    True virgins make dull companions.
     
  10. Oso

    Oso

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    I was just about to ask this very same question about radar. I seem to recall that users have responded in several different threads that if someone's radar is not pointing in the correct direction that they may have an issue with their mobile device. I may not be remembering that correctly however, so as always I am open to being corrected for the greater good. ;-)
     
    #10 Oso, Jan 12, 2016
    Last edited: Jan 12, 2016
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  11. Jeff48920

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    So for using your device's radar for navigation, as I often do, you should set your device to use "True North" to match your aircraft.
     
  12. Oso

    Oso

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    Thanks sir.
     
  13. SkyKisser

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    Sorry but may I ask where do you set the compass in iPad mini 4? There's the built in compass app I can find on my iPhone but did not see it on my new iPad mini ever since I got it. Thanks


    Sent from my iPad using PhantomPilots mobile app
     
  14. Jeff48920

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    Does your mini 4 have cellular connection? If not there is no ability to change. With. Cellular connection go to settings, then cellular>>compass>>on. Make sure your location services for compass is also on. That should get you to true north.
     
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  15. SkyKisser

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    Yes mine has cellular with a plan but still I see no option to setup compass in the cellular section.
    It's weird that I dont have the compass app to begin with. Anyone else with iPad mini 4 has the same situation?
    Does it count if I download another compass app from app store then set it to true north?
    Thanks


    Sent from my iPad using PhantomPilots mobile app
     
  16. msinger

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    There is no longer a compass app. You can find this setting in "Settings" --> "Compass".
     
  17. SkyKisser

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    Man, I tried my best but could not find any compass section in the setting. I tried in General and Maps setting but could not find it? iPad mini 4 is new, do you think maybe they took it off and keep it auto setting now?
    Thanks


    Sent from my iPad using PhantomPilots mobile app
     
  18. marzipana

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    I have an iPad Air 2 (WIFI only), and I just checked, there's no compass on that either.
     
  19. msinger

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    It's not on my iPad Mini 4 either. I was looking on my iPhone 6s earlier. This setting is not useful for the DJI GO app anyhow, so you're not missing anything by not being able to manually toggle it.
     
  20. DroneTone

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    On my iPad Air running iOS 9.2, there is only an ON-OFF switch for Compass Calibration.
    There's no compass app or obvious way to manually initiate a compass calibration when desired.

    The location of the Compass Calibration Switch in iOS 9.2:
    Settings -> Privacy -> Location Services -> System Services (scroll to the bottom to reach it) -> Compass Calibration.