All this confirms my own conclusion that all alien bases on Earth naturally establish an underground facility allowing control over any interaction.
There may or may not be homo sapiens. There may or may not be reptilians. Both are Earth evolved.
This is my first exposure to claims regarding Ground penetrating Radar. We need more data and some sort of confirmation. Most of what we see is rather shallow. Also I see zero reason for habitats been much deeper that several thousand feet in good geology. We ourselves could build there without altering physics as we know it.