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IMU calibration
1182 14 2016-1-23
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danilo rottigni
lvl.2
Flight distance : 251732 ft
Mexico
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I was shooting a whale watching tour on a boat. When we spotted the whales I started  IMUcalibration but at 90% it kent saying that it was cancelled as the bird was moved ( the Boat was moving  off course ) what can I do? Can I calibrate it at the pier before sailing, even if the Boat will be sailing acouple of miles far? Please let me know. Thanks
2016-1-23
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SkyDen
lvl.3
Flight distance : 31152 ft
United States
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Yeah I highly doubt it would ever work on a moving boat.  This is just my thought, but I would think a calibration on shore, assuming you can find a nice level surface, would be just fine so long as you didn't bang it about to much afterwards.  I could be wrong though so please don't take this as gospel.  I feel you really only need to do it after a FW update, hard landing or travel that knocked it about.
2016-1-23
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GB44
Captain
Flight distance : 343848 ft
United Kingdom
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Yes,

If you are calibrating, you need to do it on a flat level surface.
2016-1-23
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sthuemmel
Second Officer
Flight distance : 1749321 ft
United States
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Make sure there is no metal around.  Piers have lots of metal in them (bolts, nails, brackets)  I would find some place else......  Maybe in the house/hotel
2016-1-23
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Alastair
Second Officer
Flight distance : 96631 ft
Canada
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Do your IMU calibration at home.  I do it using a sprit  level and I shim the legs with paper to insure it's perfectly level.  There is no need to do an another IMU calibration until the next firmware update.
2016-1-23
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Farnk666
Captain
Flight distance : 1711394 ft
Australia
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sthuemmel Posted at 2016-1-24 05:43
Make sure there is no metal around.  Piers have lots of metal in them (bolts, nails, brackets)  I wo ...

IMU cal is not affected by metal. You are confusing it with compass calibration.
2016-1-24
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Farnk666
Captain
Flight distance : 1711394 ft
Australia
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Danilo,

IMU cal is only needed after a firmware update or if the Inspire has been subject to a knock or shock. It will NOT work on a moving surface. As stated, a known, flat surface is needed.

Compass calibration is needed if you have moved a significant distance from your last flight location. In all cases, a quick check of your sensor values should be part of your checklist.
2016-1-24
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danilo rottigni
lvl.2
Flight distance : 251732 ft
Mexico
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Hi Frank
I saw in a tutorial video that you always have to IMUCal. before each flight, are you sure you do not have to?
Following  part of your your advice I could  IMU Cal. before  boarding the ship, turn it off, pack it, and once on the spot, turn it back on and fly?
What should be the sensors values ?
Thanks
2016-1-24
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Farnk666
Captain
Flight distance : 1711394 ft
Australia
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Hi Danilo,

No IMU calibration is not needed before each flight - only after a firmware upgrade or after any occasion where the inspire is subject to shock or trauma.
(i.e. if it had a particularly hard landing, crash or if it was dropped - that sort of thing) Sensor value for IMU should be as close to 1 (will fluctuate a bit +/- .01).

Compass calibration is recommended before a flight session (but not before each individual flight) if you have travelled a significant distance from the last flight location.
For compass calibration, nearby large magnetic or ferrous objects may cause issues. A location in a field or large open area is usually fine.
There are many people who will advise that you should not have any metallic objects on your person (i.e phone, keys, etc) when calibrating your compass.
I'm of the view that this is practically irrelevant - never have bothered and never had an issue in nearly a year of flight.Compass values should be close to 1500.

So, calibrate your IMU once with the Inspire on a known, flat / level surface.
Next time you are heading out to sea, calibrate the compass before boarding the vessel.
Head out, fly safe and enjoy yourself!

Most importantly however, post back to the forum with some photos!!
2016-1-24
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danilo rottigni
lvl.2
Flight distance : 251732 ft
Mexico
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Farnk666 Posted at 2016-1-25 08:02
Hi Danilo,

No IMU calibration is not needed before each flight - only after a firmware upgrade or a ...

Will do indeed Frank.
Thanks a lot.
2016-1-24
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DJI-Tim
DJI team

Hong Kong
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yes, as the guys already said, you have to calibrate it on a flat surface, please  do not calibrate it on a boat
2016-1-24
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markaguille
Captain
Flight distance : 2031818 ft
Guernsey
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DJI-Tim Posted at 2016-1-25 08:08
yes, as the guys already said, you have to calibrate it on a flat surface, please  do not calibrate  ...

Hi Tim,

Can you clarify something for me. Some people believe the "flat surface"  has to be 100% level ie. you must use a spirit level or similar yet I have tried this and also successfully calibrated on my kitchen floor which is out of level by approximately 50mm over 2.5m ( about 1:50 or 1degree). I can see no difference in flight. Would I be correct in saying if the surface you calibrate on looks level and will not rock or move about, it will be good enough? Is a spirit level necessary?

Regards
Mark G.
2016-5-1
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vincenzomiceli
lvl.4
Flight distance : 1696781 ft
Ireland
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It is interesting how IMU calibrations are kept in such high regard. I have the inspire for almost one year now and I have never done an IMU calibration nor a compass calibration, even afterw shipping the drone back and forward form Ireland to Sicily (Italy).  The aircraft works just fine and I'm still on firmware 1.2 (or whatever was released in Aug 2015. Hence I start to believe that there may be less merit into these calibrations.  

Just my 2 cents...

V.
2016-5-1
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markaguille
Captain
Flight distance : 2031818 ft
Guernsey
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For want of a better word, I think people are being too "anal" about calibrations.  The "I have to calibrate everything before I fly"  attitude seems to be more of a problem than a necessity. People doing compass cal before every flight for instance, when they may be too close to their car or some other magnetic influence and then being surprised when their AC flies away. I always check my sensor values before take off. If there  seems to be a problem the with compass, I'll move it further away from my car or try another spot. Never had a problem. All "fly aways" that I have read about start with "I did the normal checks including calibration..."

Just my two cents.

2016-5-1
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DJI-Tim
DJI team

Hong Kong
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markaguille Posted at 2016-5-1 22:19
Hi Tim,

Can you clarify something for me. Some people believe the "flat surface"  has to be 100%  ...

That seems to be not a huge difference, but of course it is better to calibrate IMU on a flat surface
2016-5-2
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