Hello all,
Just some quick questions regarding ortho photo workflows. I'm a beginning photoscan pro user and have had some success at producing orthos with the phantom 2 vision + (that's why I'm posting here BTW). I'll have access to RTK GPS in a few weeks so I can produce GCPs. However, at present I am wondering if the following is possible without GPS:
1. Can markers be placed to help the alignment of photos so as to fix some minor issues like straightening out rooflines and vehicles (sometimes cars look like shit)? Can these markers be placed and utilized for this purpose without GPS coordinates?
2. Can the scale bars be used in a similar fashion, by placing markers without GPS coordinates, and with photos taken from the phantom 2 vision +?
3. And finally, does the phantom's onboard camera record GPS altitude? I ask because in looking at the EXIF files I only see lat and long (been wanting to know this for some time).
Any help would be greatly appreciated - just steer me in the right track. I'm very interested in learning more about better flightpath software and techniques for mapping with this phantom 2 vision +. Thank you.
Hi Jim,
To answer your questions;
1) Markers can be placed to help the alignment of the Ortho image. Preferably what you want is both GPS flight positions from the UAV and GCP's measured with RTK GPS. It can be done without flight positions but then you need an extensive GCP network as well to prevent the model from bending.
GCP's will not noticably help with artifacts that you see on building edges and other height objects. The only solution for that is extensive noise filtering (artifacts show up because of irregular height data near edges) but this is time consuming and annoying. I prefer other software to create aesthetically pleasing Orthomosaics.
They can't be added without GPS information. What you mean are manual tie points which Photoscan is unable to do so as far as I know.
2)Scalebars can only scale the model. It can't position it relative to the real world nor can it say anything about it's absolute orientation.
3) If you don't see height in the EXIF data it's safe to assume that it doesn't log it. Only way to go around is to manually add the height if you know the flying height during that time. Of course the height varies during the flight so you can't use the model that's generated this way for it's heights unless you add accurate GCP's and have it optimized just on the GCP's.