Stay tuned for more
The history of NVG development features design improvements to reduce their size, weight and power consumption (a common goal in military equipment acquisition, known by the acronym SWaP). It’s likely that future evolutions will continue to improve in these areas, not least as producers such as mobile phone and electric car manufacturers seek to develop better battery technology. Said Winkel: “Stay tuned as more enhancements are on the horizon. Measures to reduce overall helmet weight on the crew member are underway, which will increase crew comfort and reduce neck strain.” Specifically, Hackler indicated that there could be weight savings from using lighter optics – the use of polymer lenses is being explored, as these are less dense than the glass currently used. Harris is also looking at reducing forward projection, to bring the centre of gravity closer to the head, he added.
However, the next breakthrough in NVG tech may take the devices in a different direction. When you consider how modern life is dominated by digital solutions, it’s almost surprising that aviation NVGs remain so resolutely analogue. In fact, digital night vision is already in use in some military devices – and is even on sale to consumers. Retail website Night Vision, which markets digital scopes to hunters, says of the tech: “Digital night vision technology truly has turned our industry on its head. From toy store novelty only a few years ago, to today’s line of category killers, these products represent the future.”
Digital scopes work similarly to digital cameras: a sensor detects light and a screen displays the image. A gain of going digital would be the possibility to relay or record the signals, as is already the case with aircraft-mounted FLIR cameras. Furthermore, Armasite (a division of FLIR Systems, Inc.) highlights the fact that unlike traditional NVGs, they are not damaged by exposure to daylight. For flight, a major advantage of digital NVGs would be the flexibility of where you site the lens and sensor, with only the display screen being worn by the pilot – this would significantly reduce the weight of gear on the helmet.
It’s unlikely, though, that a single lens and sensor would be enough, as even if mounted in a moving turret and slaved to follow the movements of the pilot’s helmet, there would be significant, disorientating (possibly even nauseating) lag. You could, however, adopt a system similar to that used on the F-35 fighter jet, where imagery is processed from six external infrared cameras and projected onto the helmet visor. While the exact set-up may be costly to replicate (the F-35 helmet alone comes with a budget-busting price tag of some US$400,000), in 2016 Elbit Systems demoed its BriteNite system, which uses the same concept of piping digital imagery to the user. In this case, the feeds from an array of fixed external infrared and visible light sensors are processed and the appropriate section is fed to helmet-mounted goggles to match where the user is looking. In both systems, the imagery can be overlaid with instrument data and 3D mission symbology.
It’s worth noting that by using the visor for the heads-up display on the F-35, the user is afforded a wider field of view than the relative ‘tunnel vision’ of NVGs, which is often cited as a limitation on the current gear. Harris has looked at changing the field of view, said Hackler, but it seems that military aviators he’s spoken to suggested it isn’t a significant issue, as they have their heads ‘on a swivel’ in any case. Also, the trade off to increasing the field of view would be larger, heavier tubes, he noted.
On another tack, if you appreciated the move from green to white phosphor aviation NVGs, the next step could be full-colour goggles. There are a couple of ways that makers could implement this. For example, SCI Corp uses highly-sensitive digital sensors in its scopes aimed at ground users. ColorTac, on the other hand, is exploring a different methodology: a pair of matched coloured filters rotate in sync, one in front and one behind the NVG tube, providing two channels of light that the eye perceives as full colour. There are also the Sentinel-CNV goggles from Adams Industries, again for ground users, which ‘utilise proprietary modifications to deliver meaningful and repeatable colour contrast at low light levels associated with night-time operations’.
As for infrared cameras, Raytheon says it is now introducing third-generation devices, which promise even better imagery.
As with most fields in technology, it’s likely that we’ll mostly see gradual improvements in the devices offered, with occasional leaps forward, some of which may be surprising. For now, though, it seems safe to predict that we’ll move from analogue to fully digital systems. Hackler confirmed that moving away from direct-view imaging is a goal, and work is now being done to test digital night vision solutions for aviation. Perhaps today’s green-screen NVG tubes will be tomorrow’s museum pieces, fashionably retro with the hipster pilot?