On September 5, Swedish defense giant Saab announced a new feature for its existing camouflage netting. This netting is thrown over military positions, like artillery equipment or spots where soldiers are waiting in a forest, to conceal them from detection by hostile forces. Modern nettings are designed to hide not just the appearance of what’s underneath, but the radar signatures and radio signals, too, although that can make sending out communications hard. Saab is taking a stab at solving that problem with the “Frequency Selective Surface technology” for its Barracuda Ultra-lightweight Camouflage Screen. The netting, as promised, lets people underneath send out low-frequency radio signals, while preventing them from being seen on radar.

Camouflage is the technique of hiding in war. Netting is among the most basic forms, and it works along the same general principle as kids making a blanket fort in the living room—only instead of an opaque sheet concealing both occupants and outsiders from each other, the looser material of the netting, along with the way fabric and other material is hung off it, allows those inside to look out, and watch without being seen.

Initial camouflage netting was a response to visual observation by eyes and cameras, using the visual light spectrum. Radar, which sends out radio waves and then discerns where objects are located by how those radio waves are reflected back, can see through netting designed only to conceal visually. Infrared cameras, looking at heat instead of reflected visible light, can also see through netting.

Camouflage in use during a training exercise in Arizona in 2013.
Camouflage in use during a training exercise in Arizona in 2013. Joseph Scanlan / US Marines

Multispectral approaches

Newer solutions designed to take these sensors into account are called multispectral camouflage netting.

“Multispectral camouflage is a counter-surveillance technique to conceal [an] object from detection along several waverange of the electromagnetic spectrum,” reads a NATO study of multispectral nets published in 2020. “Traditionally, military camouflage has been designed to conceal an object in the visible spectrum. Multi-spectral camouflage advances this capability by contra measure to detection methods in the infrared and radar domains.”

Hiding from sensors is an evolving science—part of the constant interplay between defensive and offensive tactics and tools in military science. Militaries have interests in developing both better ways to conceal their own forces, and tools for revealing hidden enemies.

One major limit of existing multispectral netting is that, while it can protect people hiding underneath it from detection, the same netting interferes with communications sent out. Soldiers waiting in ambush, or artillery crews concealed and waiting to strike, would prefer to be in communication with their allies. Having to leave the netting to relay commands undermines the point of the netting itself.

Here’s where Saab’s solution comes into play. “Thanks to our expertise within signature management, we are taking camouflage to the next level with this novel feature. It changes how soldiers communicate while keeping multispectral protection, and so introduces a new era of tactical communication flexibility, offering unparalleled capabilities,” Henning Robach, head of Saab’s business unit Barracuda, said in a release.

To facilitate this communication, the Frequency Selective Surface technology “allows selected radio frequencies to pass easily either way through the camouflage net, while protecting against the higher frequencies of electromagnetic waves used by radar systems.”

Those facilitated frequencies could still be detected, but they represent a much less likely slice of the electromagnetic spectrum for foes to monitor, and it rules out entire categories of other sensors used today. The point of camouflage is not perfect concealment, though that certainly would be nice. What it needs to do to work in battle is confound enemies, confusing them about where the threat really is, and thus encourage foes to make mistakes or target incorrectly.

military equipment under camouflage
Camouflage in use in Italy during an exercise in 2016. Opal Vaughn / US Army

The roots of camouflage

While camouflage as a technique is so ancient it is regularly found in nature, the word itself was so new to English that Popular Science ran an article in August 1917 entitled “A New French War Word Which Means “Fooling the Enemy.””

The term gained familiarity and widespread use thanks to the hurdles of describing combat in World War I. (The Oxford English Dictionary notes that the first use of the word that it knows about occurred in the 1880s, and traces its first usage in a military context to around 1915 or 1917.) Here’s Popular Science on the popularization of the term.

“Since the war started the Popular Science Monthly has published photographs of big British and French field pieces covered with shrubbery, railway trains ‘painted out’ of the landscape, and all kinds of devices to hide the guns, trains, and the roads from the eyes of enemy aircraft,” read the article. “Until recently there was no one word in any language to explain this war trick. Sometimes a whole paragraph was required to explain this military practice. Hereafter one word, a French word, will save all this needless writing and reading. Camouflage is the new word, and it means “fooling the enemy.”

The article went on to describe a specific use of camouflage, wherein a dead horse was dragged out of the no-man’s-land between British and German trenches, and then replaced by an imitation horse with a soldier inside, allowing him to spy on and fire at the enemy from what had been just a grim feature of the terrain.

In July 1941, before the United States had formally entered World War II, Popular Science covered the work of camouflaging industrial plants from the possibility of bombing. A July 1944 story on artillery illustrated a 4.5-inch gun dug into a foxhole and covered with netting. In 1957, Popular Science showcased a Matador cruise missile under camouflage netting, concealing the weapon and its 50 kiloton nuclear warhead (more potent than both atomic bombs dropped on Japan combined). And an August 2001 story on hyperspectral imaging titled “Nowhere to Hide” showcased how satellites could see through camouflage, thanks to the different wavelengths at which actual vegetation and decoys reflected light. 

At present, it’s the tension between powerful sensors and advanced concealment techniques that make multispectral camouflage important for militaries. In the meantime, ensuring that the people under the netting can communicate with allies outside of it is a boon.

Watch a video about Saab’s camouflage netting below:

Army photo