Reducing artifacts in orthomosaic

[CoadyCameron]

I'm collecting test imagery around a bridge and I noticed there seem to be locations that consistently result in artifacts in my orthomosaic. I am using an 80-80 overlap, and have Use Geometric Verified Match turned on. The flights are relatively low altitude (30m) and flight speed was 4m/s.

You'll notice in this image that there are fragments of the bridge imagery that appears in the river on the right. On the bridge deck itself, there are little dots that appear to be the river.

 

In this image, there's a patch that was completely missed (the grey area is the DTM poking through the imagery layer where no imagery exists in the ortho). This was at the edge of the flight path leading me to believe that there just wasn't enough imagery to make a match, but I've noticed this in the middle of a flight path before as well.

The raw images themselves look fine.

Equipment:

• DJI M300
• Zenmuse P1

Any thoughts on how I can reduce the chances of getting artifacts like this?

[JerryBartz]

Our college has flown quite a few flights. We have flown with a 80% overlap and at heights from 100 -400 feet. The UAS are Phantom 3 and4. The camera has been both nadir and oblique. We have not experienced what you are seeing. But we also fly a crossing pattern (flight paths at approximately 90 degrees to one another.

Another practice is that our paths are neither into or with the wind. Gusts of wind could increase or decrease the area photographed. Also I believe we are taking one photo every 2 seconds.

Hope this helps.