H520 altitude in image metadata

[Tone-Drone]

Hello. I would appreciate some advice please with this recent issue;
On two recent site mapping missions (just for visuals - no GCPs) where I have had to change a battery mid-mission, the images from each part of the mission show different altitudes in their metadata (when looking at the image properties). On one mission plan the difference was 10m between the first half of the planned flight and the second half. On the other mission the difference was 40m. None of the recorded altitudes in the image gps metadata was close to the actual drone altitude taking account of the ground elevation and height of the drone.
Why would the drone record different altitudes for the two parts of a mission flight, when launched from the same spot and flown at the same height?

 

[h-elsner]

Everything you may want to know about GPS signals and GNSS

GPS signals and how they help with many things in our daily lives. For many users of this drone forum, we know that satellites in the sky aid our drones in flight. Most of us, are OK with just knowing that bit of info. But, in your searches for problems with your drone... you might have come...

yuneecpilots.com

Also the VDOP value in flight log data would be intresting in this case.

br HE

 

[Quadflyer Gary]

Everything you may want to know about GPS signals and GNSS

GPS signals and how they help with many things in our daily lives. For many users of this drone forum, we know that satellites in the sky aid our drones in flight. Most of us, are OK with just knowing that bit of info. But, in your searches for problems with your drone... you might have come...

yuneecpilots.com

Also the VDOP value in flight log data would be intresting in this case.

br HE

Thanks HE for directing Tone Drone to my post.
There is a ton of good GPS Reference Data in the link at the post that may answer your question. It's a long read.

 

[FR MD PHB]

For this same reason my METASHAPE software does not know how to align 2 series of photos (for modeling) separated by a few minutes for battery change.
I'm looking for the solution in the settings...

 

[Tone-Drone]

Everything you may want to know about GPS signals and GNSS

GPS signals and how they help with many things in our daily lives. For many users of this drone forum, we know that satellites in the sky aid our drones in flight. Most of us, are OK with just knowing that bit of info. But, in your searches for problems with your drone... you might have come...

yuneecpilots.com

Also the VDOP value in flight log data would be intresting in this case.

br HE

Thanks for the suggestion. The two logs relating to two parts of a mapping mission where the photos recorded different altitudes are attached (link) for anyone who might be able to make sense of them.

H520 logs - 15-12-22 - Google Drive

drive.google.com

Everything you may want to know about GPS signals and GNSS

GPS signals and how they help with many things in our daily lives. For many users of this drone forum, we know that satellites in the sky aid our drones in flight. Most of us, are OK with just knowing that bit of info. But, in your searches for problems with your drone... you might have come...

yuneecpilots.com

Also the VDOP value in flight log data would be intresting in this case.

br HE

 

[h-elsner]

The dronelogbook files are not really flight logs. That are simple files with geodata + voltage. To see GPS accuracy (HDOP/VDOP) we need files ending with .tlog.
Example: 2019-04-08 09-56-27.tlog

The date/time stamp in the file name will help to identify the error related files.

br HE

 

[Tone-Drone]

The dronelogbook files are not really flight logs. That are simple files with geodata + voltage. To see GPS accuracy (HDOP/VDOP) we need files ending with .tlog.
Example: 2019-04-08 09-56-27.tlog

The date/time stamp in the file name will help to identify the error related files.

br HE

OK, sorry. I have attached a tlog file for the relevant date in this link. Hope that one is useful.

H520 logs - 15-12-22 - Google Drive

drive.google.com