Sent by CI, this is not about Red Teaming or gear, but it's a great read and a lot of things can be learned from the small post.
During my brief and very non-illustrious military “career” (if you could call it that) part of what my unit did was trained to conduct “stay-behind surveillance” on Eastern Europe, mostly along the Warsaw Pact/NATO dividing line. Especially East and West Germany. And the Berlin Wall.
We were a special operations long-range surveillance unit. Our unit trained to infiltrate deep behind the wall and watch things. Counting. Observing. Classifying. Reading. Installing sensors called “SID” or Seismic Intrusion Devices to monitor the movement of armored vehicles along key roads, aircraft movement and anything else the Warsaw Pact was doing. Then, if all went well, we would enter the intelligence into a device we called a “dumb-dog” or Digital Message Device Group (DMDG) attached to our radios and send a burst transmission with our S.A.L.U.T.E. report, a kind of outline that classifies Size, Activity, Location, Uniforms (or Unit), Time and Equipment. After that we’d quickly change positions to another hide site since the Soviets and East Germans had a nasty habit of calling in air and artillery strikes when they detected a burst radio transmission, knowing that they were being spied on in their own back yard.