American troops use a lot of technology in combat and some aspects have been advancing rapidly. The best example of this is night vision equipment, which has undergone rapid evolution since the 1990s and has been even more rapid since 2014 when the army switched from analog night vision devices to digital ones. The latest innovation combines a scope type FWS-I (Family of Weapon Sights – Individual) thermal sight on the rifle and links it via an encrypted wireless connection with the helmet-mounted ENVG III thermal sight. Using this combination the soldier can scan the area with his ENVG and if he spots a target, he can move his rifle so that the “picture-in-picture” shows his FWS-I rifle sight lined up with his ENVG image. This way the soldier does not have to be looking in the same direction as his weapon to make an accurate shot at night. The soldier can switch between both thermal devices but because they can easily work together he can keep his weapon pointing in one direction while just turning his head to sweep the area for possible targets. Safely firing around corners or from behind any cover is easier with this twin sensor arrangement.
There are other advantages. The FWS-I weapon scope is larger, heavier and more powerful than the wearable ENVG III and is accurate out to a thousand meters for man-sized targets with 70 percent probability. The closer the targets gets the more certain the identification. This is about three times as far as ENVG and other monocular helmet-mounted devices, and provides the kind of long-range night vision previously available only on vehicle-mounted thermal sights. FWS-I weighs 740 gr (about 25 ounces), has an 18-degree field of view and uses three AA batteries that last seven hours when used alone and three hours when using the wireless link to ENVG III. There is also a daylight option when dealing with fog or smoke that is effective out to 300 meters. FWS-I costs about $10,000 each.
The lighter ENVG III has a 40-degree field of view, uses four AA batteries that last seven hours when used alone and three hours when using the wireless link to an FWS-I rifle sight. The cost is about $7,000. There is also a heavier binocular version (ENVG B) which provides a larger field of vision and better depth-perception than when using the standard monocular device. ENVG B also links wirelessly to FWS-I and provides greater capability to rapidly and accurately scan a large area.
The ENVG/FWS-I combination is initially intended for scouts and SOCOM (Special Operations Command) troops. Most infantry will use existing monocular night vision which has about the same capabilities as ENVG III but without the FWS-I link. For regular infantry platoons, one or two troops using ENVG/FWS-I can scan a wide area to support nearby troops equipped with just the helmet-mounted thermal devices. The FWS-I equipped scouts can alert the other troops to the approach of enemy forces nearly a thousand meters away and track the enemy until they are close enough for the other troops to see and fire on. At that point, the scouts can fire on more distant enemy forces while those who are closer are under heavier fire from the troops with the shorter range helmet-mounted vision devices.
ENVG first entered service back in 2009 costing about $18,000 each. Since then ENVG has evolved into a lighter, cheaper and more capable digital night vision device. This is typical of night vision devices, which first reached the troops in the 1960s as handheld, telescope-like, devices using amplified light technology. This enabled troops to see more in moonlight or starlight and proved to be an enormous advantage in combat, especially against a foe who liked to make night attacks. These early devices became smaller, lighter and more powerful over subsequent decades. Until recently the devices were analog. Then, in 2014, came digital light amplification technology. With a digital device, you get much more amplification (up to 300 times), software that can clarify a murky image or quickly adjust the amplification of a device so that a user going from the dark into a lighted room would not be temporarily blinded. Digital images can be easily transmitted wirelessly. In 2014 the digital goggles weighed 680 gr (24 ounces) and were first used successfully used by SOCOM operators. The digital light enhancement tech worked well enough with existing thermal (heat) imaging tech to quickly blend data from both to produce an even more accurate image for the user.
The digital light amplification came quickly after two new night vision designs reached the combat zone. U.S. Army troops began receiving the helmet-mounted ENVGs (Enhanced Night Vision Goggle) back in 2009 and in 2011 another major improvement; SENVG (Spiral Enhanced Night Vision Goggles) showed up. The main improvement with SENVG is a much sharper, true-color image. Troops who tested them did not want to give them up. SENVG is more expensive and the initial order was for fewer than a thousand. That has since more than tripled, but SENVGs are allocated to units that need them most.
Field testing of the original ENVG (the AN/PAS13) took place in 2005. This device worked with the current AN/PVS-14 night vision goggles (which use light amplification) but added the capability to use thermal imaging (seeing differences in heat). As more combat moved to Afghanistan, the ENVG became more critical for battlefield success at night. The ENVGs were so successful that the army ordered 50,000 so that all troops in a combat zone can have them. The ENVG was particularly useful spotting for hidden (in the brush) enemy gunmen at night. Troops equipped with ENVG have a 50 percent probability of spotting these hidden hostiles at 300 meters and an 80 percent probability at 150 meters. This made it much more difficult for enemy fighters to ambush American troops at night. Since the enemy rarely has night vision gear, they have to rely on sound and fleeting glimpses of the approaching Americans. That means the U.S. troops have to be less than 50 meters away before the enemy can open fire. Thus ENVG provided a crucial edge at night. This was great for American morale, not so good for the Taliban. The SENVG goggles simply increase the American edge.
What made the ENVG so popular was that it combines the older light enhancement technology with thermal (heat sensing) night sight. This combined goggle weighs about one kilogram (two pounds). The older ENVG (thermal only) weighed 864 gr (1.9 pounds), while the AN/PVS-13 light-enhancing device weighed 568 gr (1.25 pounds), for a total of nearly a kilogram (2.15 pounds). The new sight is not only lighter, but more compact and easier to use. It provides a total of 15 hours' use (7.5 hours for thermal imaging and the same for light enhancement). In most cases (where there is some star or moonlight) the light enhancement sight will do. But where there is no other light (as in a building or cave) the thermal imager works. The thermal imager also works through fog and sand storms.
Until 2006, thermal imaging equipment was large and bulky and only available in vehicles (M-1 tanks and M-2 Bradleys). But after 2006 smaller and lighter thermal imagers have come on to the market. The U.S. Army Special Forces has been using these lightweight thermal imagers to great effect from the very beginning of their development.
Field testing of the combined light amplification/thermal device began in 2008 and was quickly found to be popular and reliable. The earlier thermal imager was also very popular, but carrying both night sights was not. At first, the plan was not to equip all combat troops with the more expensive combined sight. That soon changed once user reports came back, praising the ENVG and describing how much of a life-saver it was. Not all non-combat troops will have an ENVG, but every unit will have some. The army found the money ($770 million) to buy over 50,000 of the new ENVGs, which cost about $15,000 each.
The SENVGs were equally expensive and difficult to produce and special operations troops (Special Forces and SEALs) got them first. The new technology in Spiral Enhanced Night Vision Goggles will be included in weapons sights as well as vehicle night vision equipment. Same with the new all-digital equipment.