Interesting (and sort of funny) article on UAV accuracy checks
just curious what everybody's thoughts are on the last paragraph of that article? statistically it makes sense of course but for general topo work where ground data needs to be within say +/- 0.05' is that acceptable enough? Anybody have any experience using that method with photogrammetry? me personally I always like to pickup things either with GPS or conventionally with a gun where the vertical needs to be tighter than that for grade tie in purposes such as EOP, curb line, etc... as it is common place to have street grades with curb here that are at 0.5% and strip pavement where grades are 0.3%
We have different techniques and equipment for a reason.
If it's practical (and the site is big enough) the UAV will give a good general accuracy (0.1' or so) with a picture (so you can find all those things you would have otherwise missed. The GPS will provide a bit higher accuracy onto things you are going to build up to, but not join - such as the general road levels around the site or the watercoiurse bed levels. The total station will provide highest accuracies to ensure road junctions are smooth and even.
It's a case of time versus accuracy: on a large enough project (or difficult enough site) then all three methods have their place - use what is best suited (or what you understand!)