The delights (?) of sound ranging. Fascinating subject. I worked with a Meteorological Troop. The Sound Ranging Troop were still using line connections to the microphones. Used to tear round the ranges in Land-Rovers known as fire-engines reeling out miles of telephone cable, which I am pretty sure was never picked up again. Always remember the microphone traces recorded on Teledeltos paper (you always get a bit of technological history on the forum!). I don't know if they ever got round to implementing connecting the microphones by radio, which Professor Bragg had been pushing since
WWII▸ . Bragg had been a sound ranger in WWI.
I think
SR‡ was used in Burma, any details will be found in:
https://www.amazon.com/Larkhills-Wartime-Locators-Artillery-Survey/dp/1844155145