I ask because I am reading a fascinating book (“Red November”-by W. Craig Reed). It is about the US Navy’s efforts to track Russian submarines, during the Cold War. Part of the US effort was an improved “HufDuff” (High Frequency Direction Finding). This was a system developed by the US and British Navies during WWII, to locate German subs.
Later, it was improved by the US Navy, for tracking Russian subs.
A few years ago, I was watching one of those ridiculous SciFi channel filler shows-about the Germans developing UFOs and “antigravity” during the final days of WWII. It was stupid, but they did show the ruins of a circular antenna array-which looked a lot like the arrays used by the US Navy.
I know the Germans were very interested in ranging systems, and General Martini (head of he Luftwaffe signals division) had a similar project-don’t know what happened to it. Does anybody remember seeing the pictures of the circular antenna array? from emory, it looked like vertical antennas arrayed in a cercle, of a bout 300 ft. in diameter.
If you google “wullenweber antenna” you can learn all sorts of stuff about HF direction finding.
I was mightly impressed by the Wullenweber array I saw when flying into Gander, NF. It is part of what remains of the AN/FRD-10 network.
ETA: I just re-read the OP and realize your question was about wether the Germans did any research into this.
Which you’ve practically answered anyway.