Signals Intelligence: Electronic Isolation Of A Target

Not too long ago I ran a short post over at Brushbeater noting a story from the Marine Corps, pairing signals collection guys with Scout Snipers in a somewhat new small unit strategy. Building on the successes SOF units have had for a long time now in recognizing the rapid value of SIGINT in the field, pairing the two elements only makes sense. The idea is to isolate a target where they’re most vulnerable- electronic communications- in order to end the fight quickly with as few casualties on our side as possible. And working from a prepared citizen’s point of view, those same capabilities can and should be reflected in your own training.

It’s not enough to simply have a scanner, however nice it might be, and call yourself good on signals intelligence. Situational awareness, maybe, maybe, but none of it will do you much good without a means to exploit what ever it is you’ve collected.

The purpose of intelligence is exploitation. 

Recording voice traffic with common items makes exploitation easy.

What that means in practical terms is that unless I can do anything with what I’m hearing, its completely useless to me. So what if I hear some traffic on a random frequency. Did I take the time to record it? What did they actually say? What is their level of training or discipline? Who’s the person in charge on the mic?

We can listen to all the traffic we want, but if we have no way of exploiting that, then we’re wasting our time.

Some of the equipment you’ll need for a signals collection package at the small unit level includes a decent scanner capable of decoding P25, a communications receiver, an inexpensive analog radio,  a recording device, a Yagi, and a frequency counter. Most of the higher end scanners on the market have up-gradable firmware that is enabling the decoding of P25 modes in use with public service as well as DMR which is very common today in the US as well as being used in Ukraine and Syria among guerrillas. A communications receiver, while similar to a scanner, will tell us the exact frequency the traffic is on, unlike most digital scanners today. We need to know this in order to have the operating frequency- its not enough to know what they’re saying, but we need to know what frequency they’re on so that if we decide to shut down their communications, we can effectively attack.

Signals collection kit laid out in the Brushbeater Signals Intelligence Course.

Our inexpensive analog radio enables us to not just have additional redundancy in our kit, but it’s also a useful exploitation tool. Depending on what type of gear your opponent has, something like a UV-5R can become our weapon in shutting their communications down. Using a Yagi to first get a bearing on their direction and then focus our signal in their direction, overloading their radios. This is beginning what’s known as isolating the target.

Once we’re in our working environment, we’ve got to come up with a competent plan of action for not just collection but exploitation. The first thing to consider is that the physical presence of the traffic itself may be significant. That begins with knowing what bands have what types of communications. For example, if I intercept something in the 462.000mHz range, I know that’s FRS and likely either motorola talkabouts or Baofeng type radios, and chances are high they’re within a mile or so of me, simply based on the low power output and restricted antennas. If I happen to come across something in the VHF range, maybe MURS, they might be a bit further out and possibly have better equipment or a higher level of training.

Once we build a working list of common use bands, the next step is taking the scanner in our signals collection kit and running a point search. Instead of doing a broad sweep of the spectrum, we target a specific frequency range that the OPFOR will be operating on. Its a technique that cuts down in the lag time in intercepting their traffic. The sooner we can lock on, the more we’ll hear.

An inexpensive Yagi is a powerful Electronic Warfare tool.

But hearing is not enough. We’ve got to be able to exploit our target. The first way to do this is to simply do nothing. Monitor them, don’t alert them to your presence. You’d want to take this route for what we call Patterns of Life missions, where a target is unknowingly under observation. Once they’ve been deemed a threat however, its time to get cranked up. Using our recorder, we can attack by simply re-playing the same conversations back to the target. Even well trained opponents may not realize what’s happening at first, and it’ll at a minimum cause confusion. With their communications cut, fear starts setting in- and from there they’ll start making bad decisions. And from there, an effectively trained fighter, even with this simple package, can isolate and shut down their communications, giving you the tactical edge and winning the fight before it even begins.


Interested in learning more? We’ve got upcoming courses in both communications with the RTO Course and Signals Intelligence, as well as a lot more. There’s only one way to learn these skills and its not just by reading. Expand you and your group’s capabilities and give yourself the edge in the fight. 

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20 Comments

  1. Anonymous September 19, 2019 at 07:19

    5

  2. Hank September 19, 2019 at 11:30

    Is the Moxon antenna as effective as the Yagi for the purposes outlined in this article? Thanks

  3. Hank September 19, 2019 at 11:44

    Is the Moxon antenna as good as the Yagi for the purpose mentioned in this article? Thanks

    • NC Scout September 19, 2019 at 13:41

      It is. While its very broad for direction finding, it’ll still give that directionality of transmission. The Yagi is the best tool for the job though.

  4. devin82m September 19, 2019 at 11:57

    Hey NCScout, I believe I’ve asked this before, but I’ve forgotten, what is that loop antenna on your Alinco? Is it very effective? Can we buy it somewhere? Also, do you suggest the Alinco DJ-X11 over the Icom IC-R6? I was doing a comparison of the newest digital Icom receiver to the Alinco, the Icom has more features, but in my opinion not enough to justify the $200 extra in price.

    • NC Scout September 19, 2019 at 13:49

      The loop antenna is a UHF Foxhunt loop from Arrow Antennas. It’s an awesome piece of gear for DFing signals on the ground. As for communications receivers, I strongly suggest the Alinco over the Icom due to the ability to directly input frequencies and the fact that it has a near field frequency detection function (known as close call in Uniden scanners). But those features come at a price, and you’re definitely not undergunned with the Icom. The frequency counter performs the same function as a ‘close call’ feature, so you’ll immediately know what frequencies the closest signals are on.

  5. devin82m September 19, 2019 at 13:32

    Duh, I KNEW that was a Moxon, man I’m slow with this cold. So what brand is that one, I like it’s tough looking construction.

  6. Operator Six September 20, 2019 at 09:28

    You can’t DF a freq with a single setup unless you’re airborne or moving hella fast. You need at least three, preferably five positions all with LOS on the target to do it correctly. Jamming freqs with recordings is fine but opens you to DF if the target has that capability. Any competent unit transmitting will have procedures to “dump” — change freqs if they think they are compromised. This means you need yet another set of guys “spinning and grinning” — monitoring the frequency bands you believe your target(s) are working on if your target dumps or has additional comms nets. Always assume your target will be working on more than one net by the way. Operational and C2 elements very rarely work on a single shared freq.

    2ID 102nd MI & LLVI/SODA. TAC SIGINT was our job.

  7. Greg September 20, 2019 at 12:03

    @NC Scout, good article, and very timely as someone put a UV-5X3 in my hands about 3 days ago. To give you an idea of what a greenhorn I am; I just figured out how to adjust the frequencies (low/high power, wide/narrow band) and store them. My first 5 channels will be MURS and #6 is Marine 16. I do, however, build my own electronics sometimes, and BTW totally got your connectors article. Worked for the Physics Dept. at a major University…you should have seen the slang come out of those folk. RCA connector could easily be translated to “funny colored connector with a male thingy.”

    6 years back, when we first started adjusting our lifestyle, I was going to mess with parabolic antennas. The idea was that there are a few of our flock spread out across the US and for initial contact at our rendezvouses we could use vectors and direct semi isolated signals to those areas, to minimize outsiders from picking it up. It went on the back burner, but one idea I had was to use a soda can as an ad hoc parabolic reflector isolator.

    This little radio has a scanner and a signal strength meter, so I’m curious if a person could cut a soda can in half from top to bottom (retaining the bottom to shield the top of antenna), and use it around the radio antenna to pick up directions? You guys mess with this all the time, so you could juxtapose it to your yagi, to check for effectiveness. Obviously, we aren’t there yet…am bringing up the rear so to speak ;)

  8. Bryce Sharper September 20, 2019 at 18:47

    What do you think of this one?

    Uniden SDS100

    • NC Scout September 20, 2019 at 22:03

      Looks good, but its pricey compared to its competitors. Might be worth it though, I’d have to get hands on with one to know for sure.

  9. Kilo September 21, 2019 at 09:44

    As someone who has done this real world during deployments and who has also taken NCS’s class, just to see how he was presenting the content with commercial of the shelf resources, I can highly recommend this course. What NCS is able to pack into two full days of training took a week to accomplish in the MIL. He is also using equipment that anyone can acquire instead of some of the proprietary stuff we used. If you are doing anything with comms, you need this skill set, if for nothing else than just to know how it can be used against you. Don’t pass up the opportunity to get it.

  10. Daniel September 21, 2019 at 13:33

    Taking what Scout says a tad further, even being able to decode public service P25 will only take you a short way. Mostly you’ll hear strings of brevity codes like, “Charlie two two, one eight seven zone four.” “Two Two ten four.”

    Great! Now what? Plus lots of public service comms is via vehicle computer and the police are especially known for taking to their phones for side chats between units or with the boss. Helps keep the freqs clear, keeps it more private and no records of who said what.

    It’s pretty rare to hear in the clear anything the average joe might find useful.

  11. Greg September 21, 2019 at 18:18

    Wow, when I received this radio it has 2 antennas. One covers 2m and 70cm, and the other covers 1.25m. So i thought, “well radios operate on a frequency, so a time base.” Having some experience with robotic module communications (mostly in cars and heavy equipment), I then went to “antennas must have a matching resistor/ capacitor circuit in the antenna.” Down the rabbit hole I went!

    In module communications (non-radio) they use very specific capacitors and resistors to limit to a very specific pulsewidth, etc. I say etc., because I’m not sure how they work VPWM exactly.

    Here’s the question; Is it possible to create a trap that is too exact? The reason I ask, is that it seems a broad range scanner would prefer a little leeway. Are certain capacitors better? I.E. Electrolytic Vs. Tantalum. 10% resistor vs. 1%?

  12. […] and infrastructure of the nation-state system or are they being democratized along with drones, electronic warfare, and other forms of hardware with dual military/civilian purposes?  This is of interest to me […]

  13. Matt in Oklahoma September 30, 2019 at 14:15

    A lot of this is over my head but I’m working on it. I appreciate the info that you and others put out.

    • johnyMac October 1, 2019 at 08:54

      Matt in OK,

      Thank you sir!

  14. Mike Fink October 5, 2019 at 10:48

    Excellent article. In thinking about the details required to successfully identify, locate , and isolate a target, I can see why formal training is the best way to take on the steep learning curve between theory and practice. In thinking about trying this out for training purpuses given the suggested kit, it occurs to me that real world hunters co-ordinating a deer drive with FRS radios would be a good practical excercise. I can envision intercepting the signals and determining the frequency easily enough, but I imagine that it would be difficult for me to get an accurate bearing on a specific target with a Yagi when the parties I am intercepting are all mobile, speaking rapidly in succession over the air, and located in 2 or 3 different general directions. Is there some additional technique involved or is it simply a matter of mastering the equipment and getting as much practice as possible? Thank You.

    P.S. I do not intent to actually interfere with any hunters or other parties utilizing the airwaves that I may utilize for RDF practice.

  15. Anonymous February 11, 2020 at 14:05

    4.5

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