Enhanced flight vision system
More recently business jets have added similar capabilities to aircraft to enhance pilot situational awareness in poor visibility due to weather or haze, and at night.
The first civil certification of an enhanced vision system on an aircraft was pioneered by Gulfstream Aerospace using a Kollsman IR camera.
Thus in poor visibility the pilot is able to view the IR camera image and is able to seamlessly and easily transition to the outside world as the aircraft gets closer.
Aircraft not equipped with such systems would not be allowed to descend as low and often would be required to execute a missed approach and fly to a suitable alternate airport.
Other sensor types have been flown for research purposes, including active and passive millimeter wave radar.
In 2009, DARPA provided funding to develop "Sandblaster", a millimeter wave radar based enhanced vision system installed on helicopters which enables the pilot to see and avoid obstacles in the landing area that may be obscured by smoke, sand, or dust.
The first EVS's comprised a cooled mid-wave (MWIR) Forward looking infrared (FLIR) camera, and a HUD, certified for flight with the Gulfstream V aircraft.
Future EVS designs focus on all-weather vision, which can be accomplished by intelligently fusing images and data from cameras operating in visible light, infrared, and millimeter-wave.
FLIRs are of two major types: one is the high-end, cooled, MWIR band (3–5 um) camera, which has better temperature resolution and frame rate but is more expensive and bulky, and the other is uncooled microbolometers which operate in the LWIR band (8–14 um) of the light spectrum, are small and cheap but are less "sharp" with regards to temperature contrast.
Natural unaided vision in the visible portion of the light spectrum, along with the near-infrared, can be improved by using high end cameras.
For example, in a strong haze situation where the whole scene is very bright and features are not distinguishable, a high dynamic range camera can filter the background and present a high-contrast image, and detect the runway approach lights further away than natural vision.
A passive millimeter wave (PMMW) camera is capable of producing a real time video image, with the advantage of seeing through clouds, fog and sand.
Use of passive millimeter wave cameras are a promising technology for aircraft based Enhanced Flight Vision Systems as well as ship navigation in low visibility, and industrial applications.
The first commercially available passive millimeter wave camera for use in aircraft was created by Vū Systems[8] and launched at the National Business Aviation Association (NBAA) Conference in October 2019.
[9] Short range passive millimeter wave scanners are in use today for airport screening[10] and many scientific research programs.
It does not rely on natural radiation bu emits radio waves, which are reflected from the target and captured in the receiver.
A synthetic image can be produced based on scene data in memory and location of the aircraft, and displayed top the pilot.
In addition to the improved sensors image, the image displayed to the pilot will include symbology, which is a collection of visual cues displayed to a pilot regarding altitude, azimuth, horizon orientation, flight path, fuel state, other aircraft etc., and in military avionics additional friend/foe symbols, targeting system cues, weapon sights etc.
[17] After beginning work in 2011, Dassault was first to certify its CVS with its Elbit HUD and camera, FalconEye, in October 2016 in the Falcon 2000 and 900, then in the 8X in early 2017.
[17] In July 2018, FAA certification of the Gulfstream G500 allowed the EFVS to provide the only visual cues for landing down to 1,000 ft (300 m) runway visual range, to touchdown and rollout, after 50 test approaches, and testing to lower visibilities could allow dropping the limit, with approvals for previous Gulfstreams to follow.
[19] Rockwell Collins's conformal overlay of EVS and SVS is expected to enter service with the updated Global 5500/6500 around 2020.
For an ILS landing to be allowed, the system must be installed on the ground, and a suitably equipped aircraft and appropriately qualified crew are required.
Not all airports and runways are suitable for ILS installation, because of terrain conditions (hills in the way of the signal, non-straight landing slope).
