We (www.gmxconsulting.co.uk) are developing a large-scale agriculture project in Nigeria (5,000ha) and started to use drones to survey and map topography.
The intention was then to use the Digital Elevation Model for irrigation planning and design. However, when we post processed the images we got very large x y z errors - please see the photos below.
1. Could anyone tell us where we have done wrong? Can we correct NOW (after the aerial survey)?
2. Also we look to outsource the drone surveying and post processing for our projects in Africa - Anyone interested please let us know.
Here are some more details:
AGL: 120 - 180m
Overlap: Front 60% Side 60%
Flight time: <60 mins
Cameras: Canon S110 RGB and NGB
Number of photos: 300-400
Photo taken out before processing: None
Many thanks in advance!
But any wild agriculture land will certainly include all type of vegetation. I guess through post processing/photogrammetry you can correct the distortion created by tall grass and trees?
You can only rely on the hard surface. To get reliable ground surface points in the vegetation areas, you are going to need a VERY good LIDAR or the tried and trusted method of physycally measuring with RTK/Total station.
Drones are not the answer to everything, they can do a lot, but not all of it...
May I suggest you do the survey at the end of the dry season, there will be no grass and I guess you may be able to correct for the trees.
The utility is an exe which takes as inputs the .tlog from a pixhawk powered vehicle and exports a csv with image names corresponding to GPS tags (lat, lon, alt). It's a PC application which would be run after the flight only.
Yes, Paul, we will be doing it again next month or so when most vegetation would be have been burnt off by the scotching sun.
Hi Luke, saw you work in Uganda. please contact me at firstname.lastname@example.org