Ok so we all know we should do a compass calibration before lift off...
I travelled 100 miles today to a new location since my last flight.
When i switched everything on the compass calibration notification was OK... not in red requiring a calibration and ready to fly.
I did a calibration anyway as is best practice.

So here is the question.... Does this mean the compass is ok as per the go app and a calibration is not necessary? Eventhough we are told its best to calibrate before every flight. Is the app wrong? or are we all just being extra cautious?

You can check the sensor reading and if the value is in the 1400-1600 region, you should be good to go.
However, it's not a very time consuming procedure to calibrate it, so it might be worth it to do it anyway.

I agee its better to do a calibration. I was just curious when i was not prompted as normal. Its the first time the app didn't ask me to calibrate

What the hell....it takes 20 seconds...just do it! I always do it even if I am going the exact same spot as the last flight....

we all just being extra cautious

Sling Shot Posted at 2015-8-14 09:58
What the hell....it takes 20 seconds...just do it! I always do it even if I am going the exact same  ...

You most definitely do not want to be recalibrating your compass every time you fly.  Doing so is increasing the odds that you are replacing a perfectly good calibration with a faulty one.  There is an excellent overview of when/where you should be doing it here: http://www.phantompilots.com/thr ... plete-primer.32829/

Many people feel they are simply being cautious so do a calibration when it is inappropriate.  However...if you happen to introduce an error due to unknown interference, you won't know it until your flight goes wrong.  In regards to compass calibration, there is certainly such a thing as being too cautious.  It is far better to understand what the calibration is for, when it is appropriate, and not replace a perfectly good calibration with an unknown one.

TAZ Posted at 2015-8-14 10:32
You most definitely do not want to be recalibrating your compass every time you fly.  Doing so is i ...

Yep. what he said.

If you guys read around, the crashes and flyaways are almost 99% from people who calibrate their compasses all the time.

One bad calibration is all it takes to lose your quad.

axidify Posted at 2015-8-14 13:05
Yep. what he said.

If you guys read around, the crashes and flyaways are almost 99% from people  ...

absolutely right, i dont know where this all started, to calibrate every time!!!
what if you are standing on a cliff that has a lot of iron
what if u r in middle of a field that has a lot of metal pipes running under neath
what if there is a magnetic anomaly where u r re calibrating
what if you r doing it on concrete with lot of rebar
what if u forgot to leave your keys and cell phone behind
what if u r too near your car
etc etc.
i have calibrated mine once after i got p3 and one more after fw update, and i have traveled over 800 miles from wv to florida,from the mountains to the beaches, without any re calibration and it flew rock solid.

Now, i will tell you that i chk mod values b4 avery take off.
i use a compass and find north, i put my take off platform with a line on it bearing north, i put the P3 nose exactly on that bearing and then i check on the app map to see if it actually is pointing north. if it is and my mod values are between 1400 to 1600, then i dont run the risk of re calibrating.

there has to be a reason to re calibrate, in my opinion off course!!
there are 2 types of thought in the compass re calibration; 1- b4 every flight and 2- only when other checks have failed b4 every flight.

i also make sure no magnetic devices, even magnetic screwdrivers, old tv sets, loud speakers, etc, come anywhere near my P3!!

i never have had any issues in over 150+ flights in all different areas and conditions.

Just to jump in to this, again. I have over 12 hours on my p3p. On  the issue of calibration, I have NEVER done it, I am running the latest firmware, I use a iPad mini2. I once got a calibrate compass message, I turned the machine off and moved it fron the sheet of iron I thought would make a good take off platform and it powered up showing all greens.
If you have a good calibration, leave it alone. It feels that this calibration has become a tribal ritual to protect you from the evil fly away demon. I would bet many of these could have been controlled by switching to ATTI and the use of basic flying skills.
Getting ready to duck. ;-).

rhutty@gmail.co Posted at 2015-8-14 15:13
Just to jump in to this, again. I have over 12 hours on my p3p. On  the issue of calibration, I have ...

I agree about the ritual part..

I only calibrate after a FW update.

If the readings are good then no need to dance ..

rhutty@gmail.co Posted at 2015-8-14 15:13
Just to jump in to this, again. I have over 12 hours on my p3p. On  the issue of calibration, I have ...

My sentiments too. I have only done the Compass calibration once when I first took it out of the box. Have never done an IMU calibration. Have had no issues on the Phantom Pro with a Nvidia Shield, and all the Latest firmware and apps.

Thanks for all the comments. I think it was a discussion worth having.  I agree that if we are all green then we are good to fly and no sense in re-calibrating what is a perfectly good compass setting. Its interestung to hear the comment that too many could be the cause of problems.... Lots online and even on this forum suggest a fresh compass calibration before every flight.... Why if its not required... I know it only takes seconds to do but if it coukd cause problems perhaps we should trust our drone settings. Some mentioned IMU but this thread was only regarding COMPASS CALIBRATION before flight. Thanks guys.

I wonder what Phantom Help would say about this? Whats the official line from DJI?

Its good to learn there is a never ending discussion about compass calibration and probably more threads about this subject then one can count.  

So far all I've heard is opinions.  

Compass Calibration is outlined in the DJI3 user manual which I believe most of you have read several times.

This is an official DJI Forum but lacks guidance and comments from DJI Technical Experts who "write the book on DJI procedures."

The statement you might mess up a good calibration by doing a new one appears to be an opinion.

So does anyone have some real facts from the DJI Technical Staff?

If so please post them.
PS.  Forgot to ask, if you've only done one compass calibration how did you know it was a good calibration?   Would your answer apply to multiple compass calibrations?

Thanks and have fun flying.

Skater67 Posted at 2015-8-15 09:39
Its good to learn there is a never ending discussion about compass calibration and probably more thr ...

Okay for your last question, you can get the compass readings from the app. Also you can check the orientation of the quadcopter in the map. point it north, the arrow should face north in the app as well. And finally, just do a minute of just hovering. If it's stable then all is good.

I'm not saying not calibrating your compass ever will save you from flyaways or weird uncontrollable crashes. It's just that its much safer to leave it as it is and calibrate only in a controlled environment.

I've watched and read a lot about phantom crashes and flyaways. Most of them are from people who often calibrate their compass. It's not 100% of the time, but still, its a significant amount.

EMF's have a lot to do with the compass. although you may calibrate it where you are taking off from (should state 1500 +-100 in the sensor read out) that does not mean that the compass is calibrated to the areas that you are flying over. environmental conditions will affect the compass as rightly said above - a proper site survey should be carried out with anticipation of compass errors happening in these areas. if you haven't already, it is good practice to create an Ops Manual - UK based pilots wanting to use their SUAS commercially require a flying qualification before applying for their permissions for aerial work (PFAW).

there is no excuse for not having a set of emergency procedures learnt cold in case something happens...

rayrokni Posted at 2015-8-14 13:58
absolutely right, i dont know where this all started, to calibrate every time!!!
what if you are st ...

Could you please tell me what should i do with compass calibration if i want to launch my PH3 from a huge metal boat/ship or a jet ski? In places where i can't calibrate compass? Can i do it before on land and take off with P (position hold) mode?

Best Regards from Norway

Thank you

r_audrius Posted at 2015-8-21 03:27
Could you please tell me what should i do with compass calibration if i want to launch my PH3 from ...

wrong compass calibration is worse than not doing one at all. i calibrated my compass twice, one when received p3 and one after fw update. i live in a mountainous area, wv, and have travelled to the beach, FL, nearly 1000miles away without any compas recalibration.
i check the mod values b4 each flight and at a new location i manually chk the compass reading in this manner:
i have a plastic 20x10 container on which i have drawn a straight line, i use a compass or the compass app on my phone and find north. i then osition the box with the drawn line on that exact bearing, then place the P3 nose on that line and then i turn on p3 and look on the dji go app map and see if it is pointing correctly. at this point i know the compass is correct and double check the mod value of the compass in the app, looking for a value between 1400 to 1600.
once i have confirmed manually that the compass readings of p3 in that location are correct i then dont bother with manually checking that location every flight. just the mod values.
imagine you are standing on a cliff that has iron in it, or a field that has big ass metal pipes running few inches under ground, or u are standing on a boat with all metal and electronic devices surrounding you. doing a compass calibration at these locations surmounts to a "fly away" that u, i am sure have read so much about on this forum.
to test how sensitive the compass is, try this (i Have): put your p3 on a concrete slap (normally 4inches thick) that has rebars, then turn on your p3 and see what the compass warning says. when i tried it gives me a "bad compass reading, please move"
these are all personal experiences and opinions. there are people that calibrate compass every flight!! and have not had any issues, but that does not mean doing a compass calibration at the wrong location is a good practice. in my opinion they have been lucky that they have not done one at a bad location. the chances of magnetic anomalies are probably low!! but on a boat probably high!!
my fingers are now numb, so i wish you the best and read all about compass calibration, and not just pertaining to P3 or this forum, and make up tour own mind.

At the risk of sounding stupid (I'm new to all this), I guess a compass calibration is different to setting the home point. The home point I assume SHOULD be done each time your at a different location? Also what is the 1400-1600 people mention?
Thanks

rayrokni Posted at 2015-8-21 04:03
wrong compass calibration is worse than not doing one at all. i calibrated my compass twice, one w ...

Thank you!

cookec2 Posted at 2015-8-21 04:16
At the risk of sounding stupid (I'm new to all this), I guess a compass calibration is different to  ...

home point is where the p3 takes off from and you must wait til home point is set b4 take off so if u use RTH it comes back to where it took off from.
1400-1600 compas mod value is under setting and sensors in ur app.
if i were you i would read the manual a few times and watch videos, otherwise You Are Going To Say Bye to $1300!!
best wishes

cookec2 Posted at 2015-8-21 04:16
At the risk of sounding stupid (I'm new to all this), I guess a compass calibration is different to  ...

The home point is done at startup via GPS . You know it's done when you get the «safe to fly» warning You ned 8 to 12 GPS lock to get the go . If you want to use the Return To Home option ( either via the app or via the RC'S RTH button ) you need GPS lock .