NIGHT DRIVING IN A HOSTILE ENVIRONMENT
By David Maxwell
Driving the family saloon in a peaceful urban environment is Standard Operating Procedure (SOP) to the average domestic motorist. The roads are familiar, there is signposting and street lights. Move into the country and you gradually loose the street lighting, so headlights go to main beam and all is well. The periphery is dark but the road ahead is well lit. Take any military vehicle and under the same conditions, circumstances are virtually the same. However, if you relocate the scenario to rural Afghanistan, for example, almost everything changes. Whatever the vehicle, it will still have a set of road lighting for civilian roads but driving on main beam down a dirt road in Helmand Province is likely to attract the unwanted attention of the local ‘opposition’. A more covert way of driving is recommended. This feature outlines a number of solutions being adopted and available to the military.
Since the arrival of image-intensified (II) night-vision devices some 40 years ago, armoured vehicles have had this facility incorporated into the driver’s viewing systems for use when ‘closed-down’. For utility vehicles and trucks of all sizes, the driver has been issued with night-vision goggles (NVGs) if required. However, in a situation with little or no ambient light to ‘intensify’ or activate the II tube – conditions that exist in many areas of Afghanistan – then infrared (IR or thermal) imaging has been introduced on an urgent basis.
At the same time, as armoured vehicles (including types previously categorized as ‘soft-skin’ that have been up-armoured against local threats) find themselves in urban environments, the need for all-round visibility has become equally urgent in order to increase the driver’s local situational awareness (LSA) against close-in threats. While the bulk of the cameras installed in such systems are of the charge-coupled device (CCD) TV-type, many with the ability to image across dawn-and-dusk light levels (i.e. into the near infrared or NIR spectrum – 0.4 to 1.5 microns), there is at least one IR imager per system, usually positioned to view the forward hemisphere of the vehicle. Some vehicles may also be equipped with mast-mounted sensor turrets (with IR and TV cameras, plus the optional laser suites should targeting data be required as well) that can be elevated to provide deeper penetration into the dark of night. Thus it may be argued that LSA systems and night-vision capability for ground vehicles go together like the proverbial ‘horse-and-carriage’
The biggest user of such systems is the US military, principally the US Army and US Marine Corps (USMC). In September 2009, the US Army’s Communications Electronics Command awarded BAE Systems and DRS Technologies a US$1.9 billion indefinite delivery/indefinite quantity (ID/IQ) contract each to produce a system of IR sensors that provides 24-hour all-weather visibility for US Army and USMC ground vehicles.
Based on the AN/VAS-5 Driver’s Vision Enhancer (DVE), originally produced by Raytheon in the late-1990s, the new system is known as the Driver’s Vision Enhancer Family of Systems (DVE-FOS). The original DVE used an external 8-12 microns (long-wave infrared or LWIR) detector with a 320×240 pixel, cooled Barium Strontium Titanate (BST) staring array, offering a frontal field-of-view (FoV) of 30×40 degrees, displaying the image produced on a TV-like screen.
As thermal technology improved, the US Army re-competed the DVE production contract in 2004, with production passing to DRS Technologies, which offered a higher resolution 640×480 pixel uncooled Vanadium Oxide (VOx) LWIR microbolometer detector (with BAE Systems taking a share of production from 2009, using an uncooled VOx LWIR microbolometer derived from that used in its AN/PAS-13C(V) Thermal Weapon Sight). These systems had a slightly larger FoV (nominally 31×42 degrees) but the system remained forward-facing
The DVE-FOS ta