Scripting landscape using C++

Hi Unreal Engine 4 community !

I am fairly new to Unreal Engine 4 (although experienced with C++ and OpenGL) and I have a project that consists in making a simulation which takes place in a real world environment (about 30km long and 5 km wide).

I do have elevation measurements for the real place with a fixed resolution in a DTED file (link for those interested : DTED - Wikipedia ).
Is there a way to script landscape generation using C++ and the information at my disposal ? From my researches I may have several ideas :

1] I saw heightmaps can be used to generate landscape. Is there a precise file specification for me to generate an image that is coherent with my measurements (in term of precision) ?

2] Can we instantiate a ALandscape object from C++ source and hack it in way to ‘push my data’ inside it
See ALandscape | Unreal Engine Documentation for class detail

3] Something with landscape splines ?

If you have a better idea (which is very likely) to succeed in this task please do not hesitate ^^.

Thanks in advance !