Sites like the Lockheed Helendale RCS or the Tonopah test range are only known to have an underground pit to support raising or lowering of test articles. But is it technically possible to have a fully underground test range?
For example the Helendale RCS Range has a "runway" like structure sitting in between the test chamber and the antenna array. For an underground facility I propose the runway like path would be enclosed in a horizontal TBM-bored or cut/cover tunnel rather than digging up an entire area. Also noting the pit one and two in the center of the "runway" if the runway has to be fit into an underground tunnel. What are some of the design considerations of the tunnel that would minimize EM interference as opposed to having the entire structure aboveground?
Then there is also the question of how to get a test article, potentially the size of an aircraft to the underground location. But that's a question for later
The Nevada test side has alot of potential to reuse the subterranean structures as test ranges.