For the R2 sensor what would I expect in degraded performance if I was flying at 80m AGL and at 6m/s when compared to the optimum flight speed and altitude?
I came to ask a similar question - Looking for the optimal height/overlap/speed in various scenarios. Today I flew at 60m, 50% overlap and 11 mph in a wooded area and I’ll be processing soon. I do wonder what I could achieve on a more conceptual basis for contours, like in a county with no topo on a prospective land development site, could I fly say at 300 ft / very low overlap and fast to generate “good enough” topo? Would help to get a best practices FAQ or video on this. I have some construction sites that are wide open and I’d assume I can fly those faster / less overlap but don’t want to have to redo stuff.
Flying at about 50m AGL and 5-6 m/s is the optimal speed for getting sub 5 cm vertical accuracy.
The higher and faster you fly, the less accurate the readings of the sensor will be. However, there are more factors at play than just height and speed.
The reflectivity of the surface you are scanning also plays an important factor. Some surfaces have a harder time reflecting back to the sensor than others. For instance, we did a scan over some transmission lines in the desert:
We were able to fly much higher and faster and still get sub 5 cm vertical accuracy because the surface reflected the light back to the sensor extremely well.
I will look to categorizing in a handy way our actual experiences with speed / height / reflectivity to give the community some more ideas on what to expect.
Just checking back in on this to see how to establish some good flight parameters for different deliverables. I keep getting asked about “GIS Level” contours in rural areas on large tracts. Would love to fly this high and fast to just get some general idea of the land (better than USGS) but need to know the bare minimums to make things work. I’ve been flying at about 75m and 30% overlap and 15mph on my last few missions and with all my GCP’s I’ve been within 1-3 in, which is within our survey threshold. It is a time with almost no leaves though, and it doesn’t snow where I work. As the foliage comes in soon I’m sure I’ll have to be slowing down.
This is very relevant to my work also but I would like to fly higher and much faster, closer to 50mph and 150m. If we get this sort of study please do the analysis at other points beyond 75m and 15mph. Thanks