DF Concerns

I’m breaking this question down into two parts so I can give the most comprehensive answer possible.

I understand that about any signal can be tracked. But what are the limitations imposed on DF in mountainous territory. Understand the emperitive to avoid developing patterns, but you still have to use comms, or you may as well throw them in the creek and go total meatspace. That is the whole idea of using QRP to begin with right? To be as discreet as possible, limit broadcast power, to compliment and enhance comm opsec techniques? My question being, what are the present known DF ranges of tracking 2 meter, is DF limited by the same limitations using 2 meter comms present, (LOS?), or is DF equipment sensitive enough that have longer stand off range, than the 2 meter comm equipment itself. Is DF of 2 meter as subject to LOS limitations as those running 2 meter comms?

It’s not that any signal can be tracked, it’s that every signal can be tracked. What this means is that everytime you break squelch, there’s the capability to be direction found.

The issue now becomes who’s listening and why.

We can usually answer this by recognizing patterns we set in what we do. Try as best we can to avoid this; but it happens.

From the Mountaineer point of view, which I’m intimately familiar with, Line of Sight communications are limited between mountain ranges. Which means in short, if you’re in the valley, your signal likely ain’t going into the next valley. Direction Finding becomes misleading due to something known as multipath propagation.


Signal “bouncing” off a mountain. Buildings can do this too.


Make sense? North/South, East/West? Roger.

The results now will be the DF’er on the ground getting pointed towards the mountain or obstacle reflecting the signal, and not the transmitter itself. This doesn’t fool ISR in the sky, but then again, unless you’re a HUGE thorn in someone’s side, they’re not going to dedicate that sort of asset to finding you. ISR is better served watching than listening; and when they listen, it’s mostly to cell phones.

As far as meatspace; well, for the most secure long distance messaging, there’s no substitute for a physical messenger. But this runs into problems of it’s own from a HUMINT perspective. That’s a whole other topic entirely devoted to tradecraft(and 99% of tradecraft is sending and receiving messages clandestinely).

Think of it this way. You have your AO, it is very rural, few roads, their course dictated by the geography of ridge lines and valleys, large farms, impassible mountains, and very steep narrow hollows, it places limitations of lets say the physical locations a DF team in their wheeled mobile unit can set up. (How common are foot mobile bush whacking DF teams?) As it is your AO, you have a local knowledge of the lay of ridges and mountains, you have practiced your comms from various locations so you know the limits of LOS comms based on geography and distance, mapped your dead spots, where the best signal on the lowest power can be acquired, the outward limits of range, etc. of your specific comms system.
What I’m thinking it is not enough just to run your comms, or run good opsec with your comms, but take proactive counter DF measures. After all, it’s your AO, you best be good at running it, and that includes understanding how DF can potentially operate in it.
Of course I could just be barking up a tree here, and the opfor runs drones 24/7 and there is no counter DF measures and the electromagnetic spectrum is totally mapped.
But then again, drones run out of fuel, don’t last forever, there is bad weather in mountains, the regime has to expend valuable and limited resources for them.

Most of the rank-and-file will work like this; they get an area to patrol, they build an Outpost, they patrol the roads and meet people in the towns for various reasons. That’s how it works in a “counterinsurgency”. Sometimes they’ll set up ambushes, usually connected to a supply line of some sort. Both stages of Chechnya saw these techniques to differing rates of success; the later much more than the former. More elite Infantry units out there will be on foot(go back and read True Light Infantry…); they’re higher trained and purpose driven. They may possess supplied DF equipment, or they may more likely do what I and many others did in Afghanistan and walk around with their own scanners. I didn’t do it to DF, it was simply to monitor the chatter and know by the signal strength that we were getting close to a Taliban repeater. This being said, we never dismantled their communications, even if we had tried, and few assets were devoted to DFing due to the time it took and few results it yielded.

We were also small in number and strictly by the numbers it takes a long time to train your more elite troops. Even then, it takes long enough time to train a guy to use an advanced radio much less figure out Direction Finding and the like; normally a SIGINT guy will get tasked to tag along on patrols dedicated to such tasks…and that causes it’s own problems if the guy doesn’t mesh well with the team. Normally your shooters will have a tag-along intelligence team nearby(yes, on foot); and again, the reality becomes the human error factor. It takes a lot of time.

This doesn’t mean get sloppy or not train; it merely points out the human factors inherent in such operations. Knowing that Conventional Forces will likely be mounted, you’ll hear them coming from the next valley over if not even further. The True Light Infantry will indeed sneak up…but that takes a lot of time, and you have to be the one setting patterns to even be targeted in the first place.

As I stated earlier, ISR really has two functions; watching the ground and listening for cell phone traffic. Now in a world without cell phones or the lack of them being used, they might begin monitoring standard radio chatter, but there’s a ton of human error factor there. Cell phone metadata is fairly cut and dry…and we still couldn’t get that exactly right.

Another thing to put into perspective is that people seem to get really wrapped around the axle about radios; all communications are tiered and purpose-driven. For intra-unit, dispersed over a few miles, or house to house in a community, our Line of Sight becomes important. For macro-level regional areas of influence, such as the Appalachian region or the state of North Carolina, HF now becomes our answer. And these are only if the need is there; discretion is used by Professionals as to what they say, when they say it, and why. It’s a tactical tool and a force multiplier; but just one tool of many.

Lowest power necessary, directional antennas from fixed positions, and as brief as possible(3-5sec) over the air…

14 thoughts on “DF Concerns

  1. Pingback: Brushbeater: DF Concerns | Western Rifle Shooters Association

  2. Hardcore46

    Short transmissions, lowest effective power output, directional antenna, frequency “hopping”, in additions to the other tips in the post. As you said, if your enemy owns the sky, you have much bigger problems than merely having your comms monitored and/or DF’ed!

  3. WRT limiting POI for VHF comms, intrasquad especially, use low power HTs and use stubby antennas, both of which limit the signal emitted.

    WRT limiting POI for local/ regional comms, strongly suggest using NVIS.

    DF is a subject all its own; start by searching “adcock array” and “interferometer.” And yes, you can DF HF skywave.

  4. mtnforge

    10-4 on terrain masking, known AO limits of probable vehicle born DF, understanding potential approach/lines of drift of foot mobile detection, known geography features of AO east west north south. Electromagnetic OODA loop.
    Future research on how to establish long distance discreet QRP HF tools/comms roger over and out.

    They say learning something new every day is good for many things.

  5. Pingback: Deployable Communications Concerns – brushbeater

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