“Guerilla Unit Sonar” – The SIGINT Specialist, by GuerrillaLogistician

Part One – The RAZORBACK Submarine and the Guerilla Unit: Why are Guerrilla Units and Submarines Similar?

Part Two – Are Guerrilla Units like Submarines? My Creative Case to Spark Your Thinking, by GuerrillaLogistician

Part Three – Guerrilla Navigation – Learn the Basics because Murphy is Watching


Reference 15A – Sounding(Sonar)

The evolution of sonar and the guerrilla units’ capabilities are remarkably similar, even though you might not expect that. Many people don’t understand how sonar works, much less how the old sonar operated. Specialized acoustic receivers in the submarine would be connected to the sonar station, where an operator would listen to the sounds in the water using a hollow tube and bulb setup. The sonar operator would get a bearing by hearing in both ears and rotating the device until he had equal sound in both ears. With practice, not only did he know what kind of ship was out there, but he could tell how far away it was. With time, you can do the same thing with modern technology and the invisible waves that make up all wireless communications.

https://dosits.org/people-and-sound/history-of-underwater-acoustics/world-war-i-1914-1918/

This is similar to what someone can do with standard off-the-shelf (COTS) devices. You can take a Baofeng radio and create your own Yagi antenna to direction find other people operating. You can find other exciting things on the airwave with more expensive equipment like good scanners and a little know-how. Even though you can’t decrypt every communication, you’ll start to realize the sounds of various devices transmitting from autonomous pumping stations to data relay devices.

Yagi antennas aren’t the only direction-finding antenna that can be easily made.  A loop antenna works as well and is nothing more than a dipole made into a circle with a small air gap. If you go down the route of a loop antenna, you will have the highest signal strength in two directions. One pointed directly at the transmitter and 180 degrees off that point. If you want more instruction on this, you can hit up the RTO/SIGINT class by Brushbeater, Tactical Signal Exploitation by Madman, or buy The Guerillas Guide to the Baofeng and reference p84 in the field version will get you going.

https://brushbeater.store/products/the-guerrillas-guide-to-the-baofeng-radio-field-version

This book covers many antennas to include directional ones. It is a more in-depth book on antennas, but a 75-year-old retired engineer doesn’t write it, so you can understand it. (This is a little fun jab at some of the smart, but very nerdy HAM guys.)

https://brushbeater.store/products/special-forces-antenna-handbook

You can start a triangulation process by using a loop antenna or even the Yagi, two separate receivers, and some inner-unit comms. You can do the same thing yourself, but it is a little more complicated.  You must know the area and directions if you only have one loop antenna. Remember, if you are operating in mountain terrain, you can receive signals bouncing off the mountainside and major buildings like city centers. This makes finding a signal more difficult.

Once you understand what you are listening for, it is remarkably simple to take your Yagi antenna and a compass held away from the large metal object to find your target.  A different person can also handle your compass and track what you hear. Ham radio operators make a game of this called a fox hunt. This is an excellent start for many people interested in direction finding because the hunter doesn’t need a license. Using the Yagi with your scanner and direction to find random constant signals is also relatively easy. You can also join groups like the Civil Air Patrol, which do this sort of thing, searching for downed aircraft and lost vessels. As your skill increases, you may even be able to track an EPIRB going off inside of a UPS truck because the boat owner assumed the signal would not transmit through a metal paint can.

A step up in sonar systems came with the advanc