To drone, RTK, both, or break out the paper and pencil?

[Burton]

We are under contract for a recently clear cut 40 acre plot of land (stumps in place) and I wanted to get more accurate contours from the property so I can start planning out our future homestead.

I already looked at the USGS contours, the national DEM files which I created contours from, the local DEM files which I created 10ft contours from, etc ... I don't feel any will help me too much as those were taken with the trees in place ... even the latest lidar scan clearly shows features on the land which were not there in person when I walked it since the scan was taken before the clear cutting. (I work with maps for a living so I am pretty familiar with the software used)

My thoughts are to try to map it with a drone using orthography and RTK correction to get 1cm accuracy, smooth that out, and create an action plan from there forward then follow up with several rescans (for just orthography) in the future to track progress / regression etc. I am curious if anyone has done this and what "stack" (to pull a word from the programming world) you use.

I have previously accurately mapped a 1 acre lot using a rotary laser, compass (in this case a suunto tandem), ruler, measuring wheel, and a gridded out printout of the property taken from satellite ... it wasn't too hard but took a while ... it seems like that would take forever on 40 acres lol

Thoughts?

[Bradbn4]

The drones can be quite fast, but do require commercial licenses depending on there use.  The higher end drones are not cheap, but can provide some very nice pictures showing details that you would miss just using pencil and paper.  You own the land, you are not selling the pictures so I would peg the use as non-commercial.

Before using drones make sure that you are not in a no-fly zone which can be found near all airports.

I have flown more than a few of the smaller (cheaper) drones, and you can get some very good pictures out of this hardware.  It is a fun hobby, has some uses that can be worth while outside of running off the squirrels eating seeds out of your bird feeder.

I have not used  RTK correction, so no input on that subject.   While 1 cm is over kill for most uses; I kind of like that level of detail.

[bobbyp]

I am a Land surveyor here in Georgia and have been using the LOKI system from GeoCue on an Inspire 2 for almost 3 years. it is a PPK system instead of a RTK, but generally more accurate.

These photo based systems are really best suited for bare earth, when it comes to vertical data. I mainly us this on quarries and a big coal ash site I have been monitoring. The biggest problem is the vertical in vegetation, which is why most of my industry is going to LIDAR based systems.

You might want to call a local surveyor for a quote, a quick topo of a cleared site would cost less than some of the RTK/PPK systems I have seen. and you could get them to set some targets with coordinates, I use 16" stepping stones from the home depot painted with a checkered board. With the ground control you could do the orthos with a mavic when ever you like.