Mapping a ball field for correcting drainage

I looked over a couple of mapping jobs today for a client who’s been commissioned to correct a badly built (poor drainage) softball field and an adjacent baseball field at a new high school. I’m concerned that the nice turf inside the ball park won’t provide enough uniquely identifiable points in the images to allow a good mapping result. Also the elevation changes of interest are about 24-inches of variation from high point to low.

I’m going to do a trial run tomorrow just to see if the photogrammetry process can work on this application. I’m planning to run a cross-hatch pattern, and am thinking about running two different altitudes, one for each direction. Maybe 250’ AGL in one direction and 200 feet in the other. Would like to run best practice conditions, and the size is not large, so time/batteries/image count is not limiting.

Would appreciate hearing whether anyone has done this successfully and what you would recommend as best-practice conditions to get the best shot at useful results. Flying a P4P at solar noon on a cloudy day with about 6mph wind. The deliverables don’t have to coordinate with anyone’s CAD drawings (yet), but I’ll be using 10 GCP’s and registering them myself with my own rover on State system corrections.

This mapping trial has already caught the attention of the school district procurement officer who is thinking about other applications if this works. So… I’d like to make it work! Suggestions appreciated. I’ll be running this flight tomorrow!

Thanks… R

If you want accurate terrain don’t use oblique images. I would suggest a standard nadir flight at 150ft with 80/65 overlaps. If you can put some evenly spaced paint spots on the ground.

Thanks Michael – Hadn’t thought about paint spots. Considering that the whole field is going to get torn up, I don’t see why not.