“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 advancement of computer technology. Sonar men went from listening to one fixed focal point to being able to scan in a 365-degree radius using a waterfall-style display. They even collected the specific sounds and display patterns for various ships. They learned about the layers of the ocean and how to hide their noises from others. This gave them a better picture of what was around them without using active sonar to give away their location. Unlike movies, submarines rarely use active sonar, and accidentally transmitting active sonar will get you in significant trouble. Foot stomp (Consider why transmitting signals is so dangerous to a submarine and apply that to the Guerrilla Unit.)

The guerrilla unit now has several pieces of equipment to mimic newer sonar capabilities. While old techniques like the Yagi antenna are tried, and true, new systems like the Kraken SDR and tiny SA ultra can augment any vehicle unit in the field or even assist an individual in finding different communications. Most COTS equipment isn’t as robust as military gear, so you have to baby it more, but the price has dropped considerably. While the tiny SA ultra won’t show you directions like the Kraken SDR, it has the waterfall feature, allowing you to watch in real-time and track previous signal spikes. Combine that with a YAGI, and you have a hybrid system to hunt down unknown communications.

https://brushbeater.store/products/tinysa-ultra-spectrum-analyzer

Setup Guide

https://www.americanpartisan.org/2023/07/tinysa-ultra-sigint-setup-by-guerrillalogistician/

Like a sonar tech, you must spend time with your gear to understand it and build your skills. I will have a link below to reference signals others have found interesting. This will give you a better understanding of what you are listening to.

Self-training map for the new guerrilla sonar technician, AKA SIGINT specialist

1. Familiarize yourself with your equipment. If you only have a radio receiver or standard radio, go online and build yourself a Yagi Antenna from the instructions. Make this for the general frequency you wish to track. Details are also in the Guerilla’s Guide for the Baofeng radio. If you are operating this in conjunction with a tiny SA ultra, follow the link for setup. Devices like the Kraken will also require research or a search on the forums and practice. While people may think specific devices are plug-and-play without proper training, they are equal to a paperweight.
2. Find a constant signal your receiver can pick up, especially if it is Audible on your radio. Use basic direction-finding skills such as body blocking the antenna or build the Yagi antenna and find a bearing. Do this at least three times from different locations. The more distance, the better. Using a map, plot your bearings from the locations where you direction found your transmission site. Then head to that location and see if you are correct. You may also look for an FM or AM antenna and verify your skills using the internet instead of traveling to the tower.  If you remove your antenna and can still hear the transmission, you are on top of the transmitter.
3. The next one will be far more difficult. You will want to find a moving signal. This could be a ham operator driving down the road, or you could buy a small fox-hunting transmitter and have a friend walk in a park or drive around town. Obviously, this will be far easier with some technology than others, such as the Kraken.
4. I left this one for now because you should do this as a completion goal throughout the process. Record your local transmissions, identify what type of signal you are listening to, and figure out who could be transmitting. Create a local log of these signals for future reference. Lastly, ensure you do this on different days and at various times. You will see a pattern develop that is unique to both. You would consider this the signal intelligence version of Patterns of Life. (There will be a future article on this exact topic.)

REFERENCE GUIDE TO SIGNALS

https://www.sigidwiki.com/wiki/Signal_Identification_Guide

Note to reader: I know a little about Sonar; it isn’t my specialty, and some comparisons may be wrong. If you wish to comment about that, great.  Hopefully, the comparison interests people in SIGINT and helps the reader think and act intentionally. All errors are acceptable for entertainment and creating interest; all corrections are welcome.