April 23, 2014: Since the latest generation of American night vision goggles are digital someone noted that it would be a simple matter to allow the digital sights now available for rifles to be linked to the night vision goggles so that the soldier could point his rifle without exposing himself to enemy fire and get off well aimed shots. Looks easy enough but it will be another two or three years before this is ready for the troops to use in combat.

This sort of thing is part of a trend. Night vision technology has been advancing at a fast rate during the last decade. These portable devices first reached the troops in the 1960s, and amplified light so troops could see more in moonlight or starlight than the enemy. These devices became smaller, lighter and more powerful over subsequent decades until now they are digital, rather than analog.

Recently the advances have been faster and more revolutionary. The latest ENVG (Enhanced Night Vision Goggle) II uses a digital light amplification technology. Until now light amplification was analog. But as 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, which is how they will link to digital rifle sights. The new ENVG II weigh 680 gr (24 ounces) and have been successfully used by SOCOM operators. The new digital light enhancement tech works well enough with existing thermal (heat) imaging tech to quickly blend data from both to produce an even more accurate image for the user. ENVG III are to be lighter, more reliable and have more features, like the data link capability.

U.S. Army troops began receiving the helmet mounted ENVGs 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 the 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 were particularly useful for spotting 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. The ENVG thus provides a crucial edge at night. This has been great for American morale, not so good for the Taliban. The SENVG goggles simply increase the American edge.

Until a decade ago, 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. What made the ENVG so popular was that it combined the older light enhancement technology with thermal (heat sensing) night sight. This combined goggle weighs about one kilogram (35 ounces). The older ENVG (thermal only) weighed 864 gr (30 ounces), while the AN/PVS-13 light enhancing device weighed 568 gr (20 ounces), for a total of nearly a kilogram (34 ounces). 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 moon light) 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.

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 ENVG IIs, which cost about $13,700 each. ENVG III is not expected to cost much more. The digital rifle sight enters service in 2015 and is basically a thermal sight that is an add-on for the existing day sight for rifles and light machine-guns.

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.