How are aeronautical charts made?
Mapping starts with basemaps, with topos (DEMs or digital elevation models) and geographic features.  Then cultural overlays are added. 

The charts in US utilize a national spatial reference system. Today this is done with GIS/Mapping software. Then overlays for aviation data, such as man made obstructions, and air navigation data is added.  

The (old) process has been the topic of many articles in pilot journals. The newer process is rapidly evolving, as the government transitions to AWS / cloud based applications.

To address your questions, the DEMs may have been created with RADAR and integrated with topo data, but today LIDAR is the norm.  LIDAR data helps with man made structures as well, while not as good as SAR RADAR, it can still show catenary and power line structures.  Those metallic structures show up very well in SAR due to their conductivity.