Non-Visual Target Indicators

This article is part of a series on the practical aspects of stealth. To see links to all of the articles on this topic, see the main page for The Stealth Fighter.

A target indicator is anything that makes your presence known to an enemy; it indicates a target (you, in this case). If you master this section, you can write the book on stealth. The purpose of camouflage is to reduce target indicators. The importance of the term “target indicator” is impossible to overstate. If you get just that from this article, it was worth your time to read it.

People spend an enormous amount of time on reducing visual target indicators. This article is on reducing your signature as a target in the domains of sound and smell. A misplaced radio crackle, or a whiff of cigarette smoke can burn you just as well as an errant movement. Let’s dive in.

Smell

In any field environment, perfumes stand out. The detergent you wash your clothes with is almost certainly scented, as is your shampoo. The simple solution is to keep your clothes for the civilized world and your field-wear separate. Wash your field wear in warm water with no detergent. It wont become rancid with stench, and yet it will not give you away. Similarly, avoid soaps, deodorants, colognes, and other such frills for a minimum of 24 hours prior to entering a field environment.

Another obvious olfactory target indicator is cigarette or campfire smoke. Don’t do it near the enemy. An unfortunate wind will leave no doubt as to your presence. Cooking food falls into the same category. You must eat, but use good judgement.

Perhaps one you didn’t consider is the food you eat seeping through your pores. This mainly pertains to situations where your potential observers are foreign. If you’d like to see this firsthand, get extremely drunk. The next morning, go for a jog. You’ll smell the booze seeping out. If you prefer not to abuse yourself that much, eat a healthy dose of curry and breathe in the same effect later.

Sound

Some sounds belong, and some don’t. The clanking of metal is sure to draw attention, as is the ringtone on your cell phone. Make sure that whatever sounds you make in a given area of operations belong, or don’t make them at all. Discipline is obviously a key factor.

The way you walk is also a target indicator. If you observe animals in the wild, you’ll note that they never just go tromping through the woods. They walk a bit, then stop, walk a bit, then stop. Crackling leaves and sticks on their own are not a definitive target indicator, but nonstop crackling indicates human movement.

Velcro, radio squelch, water sloshing, the thudding of feet on earth, coughing, and the rustling of paper and plastic are a few other sounds I can think of that cannot be easily explained away . During the Vietnam War, prior to hydration bladders, small recon teams would pass a canteen and empty it to avoid sloshing. I like to tape the metal tabs on zippered pouches, or replace them altogether with gutted 550 cord.

Weather plays a significant factor.  On cold days, sound seems to travel further. This isn’t an illusion. Sound refracts downward from warmer air toward the cold ground, which results in more sound making it further downrange prior to the sonic energy dissipating. The animals are a good bit quieter. The dried leaves and sticks crackle much more loudly than in summer. A cold, calm day is a terrible time to attempt stealthy movement.

During wet weather, leaves and sticks are muffled and make very little noise. While it may be miserable to be out in the field, you can be sure that your enemy is equally miserable, and the reduction in audible target indicators is welcome for the weary stalker.

In summary, don’t focus on purely visual target indicators. Sounds and smells can provide a searching enemy with a wealth of knowledge about your element. Don’t wash your field clothes with perfumes. Do use tape and 550 cord to silence metal and zipper elements on your kit. In the sounds and smells you make… be an animal.