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contour lines off from GCP

I've been working with recent flight data to create contour lines from DEM file. I'm seeing that the contours are about 50 ft off from GCP elevations - they are actually lower than GCP. Easy adjustment in QGIS in attributes table but am wondering if I'm missing some sort of setting during flight that caused this skewed data?

Claudia Strijek

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I don't see any jobs that used the manual realignment process in your account so I am going to assume that you are taking about just general elevation inaccuracies. 

Your most recent job did not have a Ground Reference image uploaded with it. 

https://support.dronesmadeeasy.com/hc/en-us/articles/206208583-Ground-Reference-Images

This will make a big difference in the accuracy. Map Pilot takes these images by default. Include them in your upload and the GPS derived altitude tags that are notoriously bad will not be used. Instead, the takeoff location will be looked up and the aircraft's barometric altimeter value will be added to the starting point to give much more accurate numbers.

Or... If you have GCP data you could use the Manual Realignment process which will also make this correction:

https://support.dronesmadeeasy.com/hc/en-us/articles/360000518146-Manual-Rereferencing

Zane
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Thanks so much for this. I have to say your response time to questions is excellent. Really appreciate your help!

Claudia Strijek 0 votes
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