Does Terrain Follow require RTK to be engaged?

I setup a mapping mission and said to terrain follow.  It downloaded the "internet map" while I was at home and connected to wifi.

Then, I went into the field and started the mission and it told me I needed to turn on RTK.  I did not have our Emlid or other means of connecting, so I went back and changed the mission to a fixed height.

Can I follow terrain without the RTK?

Thanks!

Yes you need RTK for TA. Without RTK your altitude is not accurate enough.

patiam Posted at 4-26 22:01
Yes you need RTK for TA. Without RTK your altitude is not accurate enough.

Thank you for confirming

I should qualify that there are DJI drones/flight apps that will let you attempt TA w/o RTK but best practices are to make sure it is fixed, especially for low-altitude TA.

I'm actually interested in this too.  I have a small island to map  7km long x 2 km wide, an 250m height. I'm using a Matrice 350rtk.  It is difficult to land on the island so I'll aim to flying several missions from a boat so I won't be able to use the RTK  (unless I can set up the RTK on the boat which I doubt?)  I'll aim to fly 120m above ground level throughout all the missions.   Is the  model elevation from the internet accurate enough for me to avoid crashing if flying 120m above the model's elevation?   The other question I guess is will the machine even let me start the mission in terrain following mode without RTK, or can I force it?

Option 2 is to plan multiple  missions such that each mission is  within specific range elevation contours.  But then I wonder how easily I will be able to stitch different missions together?

Options 3 would be to fly an high altitude coarse grain mission to build a rough DEM, and use that as the terrain following model  But for this option, will I still need the RTK?

Thanks in advance for any help or suggestions.  

Flying an island sounds fun!     Most Google Earth elevations are pretty good, so that can give you a starting point.

It seems that my 30T requires the DJI base station not our Emlid GNSS to do terrain following.  Your 350 should be pretty seamless to setup for Terrain Follow.  Do you have a base station?  My husband's drone has Auterion processing and it can do terrain following just from the map that is uploaded to the RC and the aircraft.  Mine cannot do that.

We have done a lot of mapping and 60m AGL seems to be a good height with a lot of detail.  Exactly how detailed depends on what software you are using for post processing   We use a combination of AgiSoft and WebODM.  I know there are others out there that do well.