DSM Elevation Values

[JamesMitchellEPR]

Hi everyone,

I am new to SUAV's and have recently obtain a PfCO in the UK.

I have been testing out creating DSM from the images using PrecisionMapper however the elevation values are way out.

Is there anyway to obtain elevation values that are not ~60m out without GCPs?

Do i need to modify the height in the exif's? Should these be the height + the home point elevation?

Thank you for any help with this.

 

[Meta4]

I have been testing out creating DSM from the images using PrecisionMapper however the elevation values are way out.
Is there anyway to obtain elevation values that are not ~60m out without GCPs?

That's GPS for you.
While it's very good for horizontal positioning, GPS is very poor at altitude.
It can commonly be +/- 60 metres or more and it swings over short time periods.

Do i need to modify the height in the exif's? Should these be the height + the home point elevation?

Photogrammetry software understands the GPS altitude issue and gives you good relative altitude but needs GCPs to pull it into line with your local datum.