Good afternoon to all!
I am fairly new to this and am just starting to get used to the Pix4D software. I am using this tool to try and simulate a pond filling up with water in order to estimate its volume. We flew a pond and had the images processed (p4d). In the Pix4D Desktop application, I was using the “Custom Altitude” option in the Volume Settings and increasing the base surface until the water level rose to the spillway (top left of pictures). I pulled a graphic from Google Earth to see how close the simulation was to the actual imagery. It was off by more than I am comfortable with and am not sure what’s going on. I had expected the water to reach the trees on both sides of the pond at the same time (as shown in GE photo).
Again, I am new to this, so I am wondering if adding some GCPs may have helped (I wouldn’t think it would matter too much because I am only interested in the local data for calculation purposes (I couldn’t care less if this pond was in Australia or Arizona). Does the photogrammetry software have a degree of error that would cause this inconsistency? This pond was flown late in the day (shadows), would that make a difference in the processing?
Granted, these images were not flown on the same day, in fact they are a couple years apart. I would not think the sediment would cause such a drastic change in the fill pattern, but who knows?
Any help would be greatly appreciated. Pix4D seems to be a great tool and I am hoping it will work for the projects I am currently involved in. Thanks!