Discrepancy In Flight Record

[MRomine]

This may not be any big deal but as I'm looking over my flight records on my SC, in the left 1/3 of the window it shows Top Distance, Top Altitude and Top Speed. On the right side the 'Flight Data' (ALL) has more details. Intereestingly on the left thrid it says that my Top Altitude was !,013 ft and that occured on 11/24. On that date I was doing a commercail job but I know that I was no where near that altitude in fact on the right side of the screen in the 'Flight Data' (ALL) it says that my Top Altitude for that date was 115'. Why the descrepency?

 

[brett8883]

This may not be any big deal but as I'm looking over my flight records on my SC, in the left 1/3 of the window it shows Top Distance, Top Altitude and Top Speed. On the right side the 'Flight Data' (ALL) has more details. Intereestingly on the left thrid it says that my Top Altitude was !,013 ft and that occured on 11/24. On that date I was doing a commercail job but I know that I was no where near that altitude in fact on the right side of the screen in the 'Flight Data' (ALL) it says that my Top Altitude for that date was 115'. Why the descrepency?

It correctly says “altitude” in the summary data but actually means “height” in the actual record. Your top altitude is the heightest point you took off from above sealevel

 

[MRomine]

It correctly says “altitude” in the summary data but actually means “height” in the actual record. Your top altitude is the heightest point you took off from above sealevel

Interesting, I did not know that. Very helpful little tidbit of information! Thanks!

 

[DanMan32]

It correctly says “altitude” in the summary data but actually means “height” in the actual record. Your top altitude is the heightest point you took off from above sealevel

I don't think that's true. Here in Florida near the gulf, I don't think I took off from any point 129ft above sea level. It's possible, but not likely.

It also says my M2 top altitude was 19ft yet I know my house is closer to 40ft AMSL.

 

[Meta4]

I don't think that's true. Here in Florida near the gulf, I don't think I took off from any point 129ft above sea level. It's possible, but not likely.

It also says my M2 top altitude was 19ft yet I know my house is closer to 40ft AMSL.

It's true ... but the height is derived from GPS or possibly from the barometer assuming standard atmospheric pressure and is not accurate.
Climb one of those landfills or find a real hill and launch from there and see if you get a new top altitude.

 

[DanMan32]

Yes I understood you meant GPS. The M2 SRT shows height as MSL which would have to be from GPS. Height by barometer is always from a barometric reference which would be at takeoff as 0 altitude. I've definitely flown higher than 129ft.

 

[DanMan32]

So the flight I supposedly took off at 129ft MSL was Oct 28, 2018 at a park I frequent. I have 3 ACs shown: my P3, my original M2 and my replacement M2. It's the replacement that shows 129ft. I've flown my P3 there, only shows 89ft. Park is around 40ft.

 

[Meta4]

Yes I understood you meant GPS. The M2 SRT shows height as MSL which would have to be from GPS. Height by barometer is always from a barometric reference which would be at takeoff as 0 altitude. I've definitely flown higher than 129ft.

So the flight I supposedly took off at 129ft MSL was Oct 28, 2018 at a park I frequent. I have 3 ACs shown: my P3, my original M2 and my replacement M2. It's the replacement that shows 129ft. I've flown my P3 there, only shows 89ft. Park is around 40ft.

The Top Altitude probably comes from the barometer since that's the source of EXIF data MSL altitudes.
EXIF MSL altitudes are notoriously inaccurate - +/- 200 ft is not unknown.
Whether you believe it or not, the Top Altitude is referring to the highest point from which you have flown, and that's easily confirmed with a little testing.
Finding a decent hill to launch from would help.

I recently set a new Top Altitude much higher than the previous highest.
The new Top Altitude was 1792 metres which is very close to the height of the mountain I was flying from.
I only flew to 80 metres above the launch spot on that flight.

 

[DanMan32]

The barometer cannot give you AMSL. The AC, absent of altitude from GPS, has no idea what the AMSL is.

 

[DanMan32]

The Top Altitude probably comes from the barometer since that's the source of EXIF data MSL altitudes.
EXIF MSL altitudes are notoriously inaccurate - +/- 200 ft is not unknown.
Whether you believe it or not, the Top Altitude is referring to the highest point from which you have flown, and that's easily confirmed with a little testing.
Finding a decent hill to launch from would help.

I recently set a new Top Altitude much higher than the previous highest.
The new Top Altitude was 1792 metres which is very close to the height of the mountain I was flying from.
I only flew to 80 metres above the launch spot on that flight.

I just gave you my test. The park I flew from that according to you it's saying is 129ft AMSL is not 129ft. It's closer to 40ft or lower.

 

[Meta4]

The barometer cannot give you AMSL. The AC, absent of altitude from GPS, has no idea what the AMSL is.

The barometer can't directly give MSL altitude but DJI derive a rough MSL figure from barometric data.
This is where the EXIF altitude data comes from.

I just gave you my test. The park I flew from that according to you it's saying is 129ft AMSL is not 129ft. It's closer to 40ft or lower.

You don't have to believe me but I actually know what I'm talking about and explained it in post #8.
Perhaps a picture would help show you how inaccurate this number can be?

Although the field in the EXIF data is labelled GPS altitude, that's DJI's error as the data is derived from barometer data.

So one more time ... the Top Altitude figure is an approximate altitude for your highest launch point.

 

[WithTheBirds]

The barometer can't directly give MSL altitude but DJI derive a rough MSL figure from barometric data.
This is where the EXIF altitude data comes from.

You don't have to believe me but I actually know what I'm talking about and explained it in post #8.
Perhaps a picture would help show you how inaccurate this number can be?

Although the field in the EXIF data is labelled GPS altitude, that's DJI's error as the data is derived from barometer data.

So one more time ... the Top Altitude figure is an approximate altitude for your highest launch point.

I will give you one more time Meta- I have never seen a depicted altitude in my EXIF data that came close to an actual anything.