It's not well-known, but the British tracked the Germans down to the unit level using radio transmission triangulation, and plotted their positions across Europe on giant maps. Even without decrypting signals, they knew a great deal.
The Germans were the first army to have radio on every vehicle, sometimes 3 for higher ranks. It was handy on the go, but leaked intelligence like a sieve when stationary for days, and the Germans were overconfident in its secrecy.
The British were warned of air raids even before takeoff because German pilots followed a procedure of testing their radio on the ground.
The mastermind behind the British effort built a similar system, but global, for the US, after WW2.
SR-71 flights initially used radios, but since Russian "trawlers" were tracking the broadcasts, later flights, including multiple refuelings, were done in radio silence.
The Germans were the first army to have radio on every vehicle, sometimes 3 for higher ranks. It was handy on the go, but leaked intelligence like a sieve when stationary for days, and the Germans were overconfident in its secrecy.
The British were warned of air raids even before takeoff because German pilots followed a procedure of testing their radio on the ground.
The mastermind behind the British effort built a similar system, but global, for the US, after WW2.
SR-71 flights initially used radios, but since Russian "trawlers" were tracking the broadcasts, later flights, including multiple refuelings, were done in radio silence.