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  1. thunderbird

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    What's the difference between compass calibration and calibration using dji assistant on your laptop
     
  2. Mark C.

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    I'm new but have been studying and I believe what you are supposed to do is, anytime you're talking off from a new location you should calibrate your compass in your AC. I think the reason is for helping the return home function to more accurately locate your RC. I calibrate my compass before every flight. Hope this helps, and if I'm wrong somebody please correct me.
     
  3. Mark C.

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    Compass Calibration, A Complete Primer
    Why Calibrate?
    Compass calibration is important to safe, controlled flight. It compensates for changing background magnetic "noise", a.k.a. magnetic inclination and deviation (not to be confused with declination). Inclination and deviation that isn't corrected through compass calibration will cause inconsistencies between GPS and compass that can result in "toilet bowl effect", a swirling motion that can cause the Phantom to fly out of control.

    What is Magnetic Inclination and Deviation?
    Magnetic deviation is a horizontal variation that comes from the Phantom itself and the equipment you have installed on it as well as the magnetic makeup of the area you are flying in (again not to be confused with declination). Sometimes the deviation will be insignificant, but other times it can be big enough to cause you to lose control. Inclination is a vertical magnetic variation that shifts depending on where you are.

    Warning Signs
    The Phantom can only detect when the compass is providing extremely poor (implausible) data. This typically occurs if you place it near a strong magnetic field or do not calibrate it properly. It will flash red and yellow lights and the P3 will indicate a compass error in the app.

    <font color="#ff4d4d">IMPORTANT: The lack of a compass error does NOT mean your compass is working and calibrated properly.

    MOD Value
    This is the total magnetic field calculated using the "sum of squares" from the X, Y and Z axes. On the P2, you need to plug in the cable and use the assistant software. For the P3, you can see it in the app. It should be between 1,300 and 1,600, ideally just above 1,400. Check it away from magnetic influences. If it reads very high or very low, check it again in a different location. If it is still off, it could need calibration or it could be magnetized or damaged.

    <font color="#ff4d4d">IMPORTANT: A good mod value does NOT mean your compass is working and calibrated properly. For example, if you calibrate next to some rebar, your mod value may still be OK until you fly away from the rebar.

    What Does Calibration Actually Do?
    Calibration measures the magnetic fingerprint of the surrounding area. By turning the compass 360 degrees, the Phantom can see where the compass reading doesn't smoothly increase or decrease. It uses this information to build an adaption table so that when the Phantom turns during flight, the reading is smooth and linear.

    When Should I Calibrate?
    You do not need to calibrate before every flight and in some cases you definitely should not calibrate. That doesn't mean you shouldn't ever bother doing it. It only takes one time for it to go very wrong. The most important aspect of compass calibration is making sure the magnetic "neighborhood" around your Phantom is consistent between calibration and during flight.

    <font color="#ff4d4d">IMPORTANT: The ideal place to calibrate is an open field with nothing metallic in a 20ft radius. Keep away from drainage pipes, irrigation systems, rocks, etc.

    * DO Calibrate

    -
    * Mod value out of whack or compass error reported (check area first).
    * Circling in flight (also check for other possible causes).
    * New equipment added or removed / new firmware installed.
    * Location change (greater than ~100 miles).
    * Significant change in terrain (e.g. to / from mountains).
    * If you just degaussed your compass (BTW, don't degauss unless instructed).





    * <font color="#ff4d4d">DO NOT Calibrate

    -
    * <font color="#ff4d4d">If near concrete, buildings, and hidden or overhead power lines / pipes / etc.
    * <font color="#ff4d4d">If you're indoors, on a paved surface, on a stone surface, on the beach, on a boat, on a balcony, near a car, near speakers, etc.
    * <font color="#ff4d4d">If there are metallic (ferrous) objects nearby or you're not sure





    * Pre-Calibration Checklist

    -
    * Everything used in flight should be powered during calibration, e.g. GoPro, tracker, etc.
    * Remove all metal from within 10ft radius, e.g. watch, phone, ring, belt, coins, controller.
    * Calibrate on grass or dirt and not on concrete, asphalt.
    * Calibrate on a level surface if possible.
    * A cardboard box is a good idea to get it off the ground and level.





    * How to Calibrate

    -
    * Power up your Phantom and accessories as normal.
    * Wait until your Phantom is ready to fly.
    * P1 / P2: Flip S1 five times between the top two positions.
    P3: Select CALIBRATE under AIRCRAFT STATUS | COMPASS. Click OK.
    * Confirm solid yellow rear lights.
    * Pick up the Phantom and turn it smoothly and steadily a full 360 degrees until the lights turn solid green.
    * Point the front of the Phantom straight down and repeat until the lights turn off and resume normal flashing.
    Note: Don't be concerned if your gimbal reacts poorly to being face down, keep turning as normal.
    * Optional: power off and restart Phantom.
    * Enjoy your flight!




    If for any reason, you do not complete any of the above steps smoothly and evenly, restart the process.
    http://www.phantompilots.com/index.php?posts/301070/


    Sent from my iPhone using Tapatalk
     
  4. snowghost

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    You definitely should not calibrate your compass every flight. If you go 100s of miles away, then I would. Just get a good initial calibration and then always check the values in the app before flying.
     
    JamesH likes this.
  5. JamesH

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    Mark, great post, thank you. One more question. Does the KP index I see provided in some different apps (e.g, Hover) play into this at all?
     
    Mark C. likes this.
  6. snowghost

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    That is somewhat controversial amongst our fellow forum members. Theoretically strong solar storms can mess up GPS.

    If you're doing waypoint flying or great distances, I would pay attention to the index if it gets high.
     
    Mark C. likes this.
  7. EddieM

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    The KP index is a measure of disturbance in the Earth's geomagnetic field. If high enough, I suppose it would interfere with the compass or it's calibration. Like most geomagnetic disturbances, it could also affect the radio link between the RC and the aircraft. Here's a link to a Wikipedia entry.
    K-index - Wikipedia, the free encyclopedia
    Just Google KP index and you'll have more than you ever wanted to know!


    Sent from my iPhone using PhantomPilots mobile app
     
    Mark C. likes this.
  8. Mark C.

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    I believe EddieM answered the question.
     
    EddieM likes this.
  9. thunderbird

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    So what difference between calibrating using your computer then