My flight report gives a value for Maximum Take off Altitude of 85.8 metres.  On a recent flight the screen showed an altitude of 77 metres and the the report on that flight gave an altitude of 38 metres.
Can someone please advise if the Maximum Take Off Altitude is the max altitude from which my drone has taken off by the previous owner. If so, can I correct it to show the value for my fligjts only? The altitude is only about 10 metres in my flight area.  As the maximum flight altitude on the report 38 metres is significantly different from indicated during my last flight, is there possibly something wrong with my altimeter, or the report algorithm.

Are you sure your not conflicting feet with mtrs in the settings somewhere?
Where are you getting these reports from are they direct from the flight log file?
You cannot completely remove previous flights from previous owner. The drone records all flights from manufacturing all the way through to total destruction.
It kinda works like a black box in theory it records every flight the the drone does.
You can in the flight log delete individual flights if you wish but you will never be able to completly get rid of all flight data that a previous owner has made.

The app will show the date of the highest takeoff so you can tell if it was before you bought it.
Earlier flights would only be showing in the app, if you are using the same tablet that the initial owner used.
You can delete any flights from before your time by swiping and hitting the delete icon that appears.

As far as your flights altitude not being correct can you please give a little more specific detail as to what you mean?
Are your flight log files not matching your actuall flight altitude as seen during flight?
For instance if you fly to a max altitude of 30 mtrs is your log file showing something different

38m is only 28m away from 10m.  GPS height measurements are often very inaccurate, a 28m error is not unexpected.

Nigel_ Posted at 2018-2-21 02:43
38m is only 28m away from 10m.  GPS height measurements are often very inaccurate, a 28m error is not unexpected.

Thanks Nigel
The problem is that during the flight the reading in was 77 metres and the report was 38 metres.  An error of 50% seems bit much.

Hellsgate Posted at 2018-2-21 02:21
Are you sure your not conflicting feet with mtrs in the settings somewhere?
Where are you getting these reports from are they direct from the flight log file?
You cannot completely remove previous flights from previous owner. The drone records all flights from manufacturing all the way through to total destruction.

Thanks Hellsgate.

The data is all in metres. The report is from the flight logs.

Labroides Posted at 2018-2-21 02:22
The app will show the date of the highest takeoff so you can tell if it was before you bought it.
Earlier flights would only be showing in the app, if you are using the same tablet that the initial owner used.
You can delete any flights from before your time by swiping and hitting the delete icon that appears.

Noted , Thanks Labroides

Hellsgate Posted at 2018-2-21 02:24
As far as your flights altitude not being correct can you please give a little more specific detail as to what you mean?
Are your flight log files not matching your actuall flight altitude as seen during flight?
For instance if you fly to a max altitude of 30 mtrs is your log file showing something different

Yesterday I flew to 77 metres and the flight log shows 38 metres. This has occurred during the seven or so flights since purchasing the drone ,Thanks Nigel

Barry R Posted at 2018-2-21 05:13
Thanks Nigel
The problem is that during the flight the reading in was 77 metres and the report was 38 metres.  An error of 50% seems bit much.

I'm not sure what figures you are looking at.  

Note that the in flight readings are relative to the take off point.  The take off altitude is thus zero, however a record of maximum take off altitude must be a GPS height, relative to sea level.

Have you synced your flights to the DJI servers?

Nigel_ Posted at 2018-2-21 02:43
38m is only 28m away from 10m.  GPS height measurements are often very inaccurate, a 28m error is not unexpected.

Gps doesnt measure the hieght in the drone that is done using a barometer i believe

Hellsgate Posted at 2018-2-21 12:12
Gps doesnt measure the hieght in the drone that is done using a barometer i believe

The GPS does measure height above sea level.  As far as I know it is not used for anything, certainly it is the barometer that is used for maintaining height while flying, but the GPS height of the home position is recorded in the log files along with the GPS coordinates, which I assume is what we are talking about in the OP - "Take Off Altitude".  If "Take Off Altitude" used the barometer then it would always be zero!

I was refering to inflight altitude measurements as this is what the op is referring to.

Yesterday I flew to 77 metres and the flight log shows 38 metres. This has occurred during the seven or so flights since purchasing the drone ,
Not the actuall altitude above sea level.

Take off point should have been 0 mtrs according to the drone then he flew to 77 mtrs but flight log only shows height at 38 mtrs.
This has nothing to do with a gps altitude above sea level this sounds more like a problem with the barometer

Best advise is to ignore that "Max takeoff altitude" information, it is buggy as hell and vary with  different App versions.
Think of it as some show off that DJI at some point think was a nice feature but not usable for anything at all ...

Thank you KedDK.
I'll take your advice. However I still can't accept the in-flight reading of 77 metres and the log reading of 38 metres. I will keep checking a few more flights see if there is a 50% factor involved and if so , start the thread over again
Regards Barry

KM5RG-Robert Posted at 2018-2-21 06:42
Have you synced your flights to the DJI servers?

Thank you Robert
I have not synced with the DJI servers. Is the procedure outlined in the manual or covered in a tutorial?

Regards

Barry

Barry R Posted at 2018-2-22 00:23
Thank you KedDK.
I'll take your advice. However I still can't accept the in-flight reading of 77 metres and the log reading of 38 metres. I will keep checking a few more flights see if there is a 50% factor involved and if so , start the thread over again
Regards Barry

"in-flight reading of 77 metres and the log reading of 38 metres."
Can you provide some screenshots in order to show what you actually see and to document the issue to DJI?

Barry R Posted at 2018-2-22 00:26
Thank you Robert
I have not synced with the DJI servers. Is the procedure outlined in the manual or covered in a tutorial?

Synching your flight records won't make any difference to what shows on your app.
But to do it, all you have to do is click the cloud icon up in the top right corner of the flight records page and wait while it happens.

Well bottom line is this.
Are you getting any error msgs ?
Does the altitude reading really effect how you fly?
Are you really that concerned about the altitude reading in the flight log?
If your answer is no to all of the above then answer this simple question ... which altitude reading is correct the inflight one or the flight log either way it doesnt really matter.
Go out and enjoy your drone ...life is way to short to be worried about minor issues.

Hellsgate Posted at 2018-2-22 02:32
Well bottom line is this.
Are you getting any error msgs ?
Does the altitude reading really effect how you fly?

Thanks Hellsgate
I would be really mad if having set RHM at 60 metres and it comes back at 30 metres and hits a tree.
No error messages. Will keep flying and see if the error persists.
Regards
Barry

Barry R Posted at 2018-2-22 02:44
Thanks Hellsgate
I would be really mad if having set RHM at 60 metres and it comes back at 30 metres and hits a tree.
No error messages. Will keep flying and see if the error persists.

If your concerned about rth altitude then test it.
Find a clear open area fly your drone 50 - 60 mtrs away at an altitude of say 20 mtrs in flight measurement then hold rth button down for 3 seconds then monitor your in flight info to see what altitude it flies at on the way back. In theory it should climb to your preset altitude lets say for example 50 mtrs then return directly above the rth point it should then rotate to point in the same diirection it took off from then land itself gently and shut down the motors.
If it does not do the above in that sequence then you have a problem ok just be ready to cancel the rth feature.
You should see this option on the left hand side of your screen ok if at any point you think the rth is not performing correctly then cancel it immediately and land the drone manually i would then not fly again untill you get your issues resolved. To do that i suggest you contact dji support and get a case started with them.
I dont think that you will gain a solution to your issue in this forum ok.
Ii think if your problem persists then it will need to be sent in for dji techs to look at.

Thanks Hellsgate

Over and out

Barry

So,  for future reference,  I had notified Drone Base that the MetaData in the picture files for an Inspire 1 was VERY different than the ON SCREEN reporting of altitude.

That solved alot of issues regarding the File info and what was expected.  I have NOT yet checked the P4P for this difference.  I would assume the GPS MetaData is different than the AGL reported ON SCREEN.

Something to think about......

rwynant V1 Posted at 2018-2-24 19:20
So,  for future reference,  I had notified Drone Base that the MetaData in the picture files for an Inspire 1 was VERY different than the ON SCREEN reporting of altitude.

That solved alot of issues regarding the File info and what was expected.  I have NOT yet checked the P4P for this difference.  I would assume the GPS MetaData is different than the AGL reported ON SCREEN.

Thank you rywantV1
I couldn't follow the gist of your message . Would you please repeat a little more specifically.
Barry

Nigel_ Posted at 2018-2-21 02:43
38m is only 28m away from 10m.  GPS height measurements are often very inaccurate, a 28m error is not unexpected.

Height flown is based mainly on Barometer ..... GPS only gives height when in full 3D mode and then it is highly inaccurate.

I made error when I first started flying DJI - assuming GPS was in the equation. But its not. DJI have sensibly set the height by Barometer.

The item that can confuse some is the reference used.

Charted uses height above Mean Sea Level...... but DJI barometer uses as reference the take-off point.

Therefore a take off point can be at 50m height above MSL but DJI barometer sets it as 0.  It also works in negative ... if your take off point is below MSL .... say you live in Holland for example ... then DJI still say 0 ... but actual and charted is -ve.

Nigel