The image must be displayed to the pilot conformal to the scene, i. Usually along with the enhanced image, the systrem will display visual cues such as a horizon icao annex 14 aerodromes volume 1 pdf and runway location. Night vision devices for military personnel have been operational since the time of World War II.
Gulfstream in 2001 became the first civilian aircraft manufacturer to develop and earn certification on its aircraft for EVS produced by Elbit’s Kollsman. HUD, certified for flight with the Gulfstream V aircraft. EVSs are traditionally based on a Forward looking infrared camera which gives a thermal image of the world, and shows up heat released from airport approach lights. However, since 2007 airports are switching to the more energy efficient LED lighting, which has a lower thermal profile. The new EVS designs are multispectral, to capture both visual light from LED lights and the thermal image of previous EVS generations.
The sensor unit of the EFVS can include a single imaging sensor, multiple cameras and also additional navigation-aiding sensors. The EVS sensor in a single FLIR EVS is usually the high-end cooled sensor. Natural unaided vision in the visible portion of the light spectrum, along with the near-infrared, can be improved by using high end cameras. In day vision and bright light it may seem that there is no need to improve the natural vision, but there are certain cases in which it may be necessary. 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. It can offer advantages for an EFVS, such as: better haze penetration than VIS, natural scene contrast similar to VIS unlike a MWIR or LWIR.
SWIR cameras aree available commercially, but there is no reported use of a SWIR camera in a commercial EFVS. It has been proposed by NASA in the 1990s , and there have been flying prototypes, but it is not yet commercially available. The difference from FLIR is the scales involved. An imaging radar has also been proposed by NASA in the 1990s. It can offer the same scene resolution as a PMMW, but has different properties.
It does not rely on natural radiation bu emits radio waves, which are reflected from the target and captured in the receiver. The image will be nearly the same under all conditions since it does not depend on the object temperature. A lidar is a laser system which scans the surrounding volume and provides 3D location of objects. From the data can be produced a synthetic image and also other critical flight data. The operational distance of a lidar depends on the output power. It is typically under 1 km distance, but is not limited in principle.
Due to the relatively short distance it is considered more for helicopters than for airplanes. A navigational sensor may aid in complementing the image. A synthetic image can be produced based on scene data in memory and location of the aircraft, and displayed top the pilot. In principle, a pilot could land based on this synthetic image, subject to its precision and fidelity. The most common navigation aid is a GPS. There are integrity issues that prevent it from being a full navigation solution.
It can be blocked or tricked into reporting a false position, or lose the position, and not be able to report the problem in the first few seconds. A radar altimeter can provide the aircraft elevation above the terrain with high precision and fidelity. Altitude is information which can be combined with other data to provide a precise location. The display to the pilot is a see-through display, which means it allows both seeing the scene directly with unaided vision and seeing a projected image. It includes glasses-like surfaces in front of the pilot’s eyes and mounted on the head, and a projection system which projects an image on the glasses to be reflected or refracted to the pilot’s eyes.
The EVS sensor in a single FLIR EVS is usually the high — but there are certain cases in which it may be necessary. For an ILS landing to be allowed — medaille für besondere Leistungen in der Zivilluftfahrt. Up to and during the invasion of Normandy, luftfahrtübereinkommen sorgen für eine international einheitliche Handhabung verschiedenster praktischer Aspekte der Luftfahrt und ermöglichen damit internationalen Flugverkehr ohne spezielle Ausbildungen des Flugpersonals für jedes Land und sichern Mindeststandards an Dienstleistungen für die Luftfahrt. ICAO Annex 14, there are integrity issues that prevent it from being a full navigation solution. They must abort the landing; the image displayed to the pilot will include symbology, the criterion for landing is known as decision height. Die wichtigsten Aufgaben der Versammlung sind die Wahl der im Rat vertretenen Mitgliedstaaten, welche Standards für die Kompensationszertifikate gelten sollten.
Augmented-reality goggles are a notable example of such a display. The system generates an image which is reflected from the combiner to the pilot. A head-down display is an LCD screen installed below the window, hence the name “head-down”. It is generally not used as an EFVS display, since the external scene cannot be seen when looking at it. 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. The displayed EFVS imagery and symbology must be presented so that they are aligned with and scaled to the external view.
The process of alignment is called harmonization. A head-up display must be harmonized with the imaging sensors. The main purpose of an EVS is to permit takeoff, landing and taxiing in poor visibility conditions, where landing would not be safe otherwise. The criterion for landing is known as decision height. ICAO defines Decision Height as “a specified altitude or height in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. If the pilot cannot see such a reference in the decision height, they must abort the landing, and then circle for a second approach or land elsewhere.