As a method and device for representing the horizon on board an aircraft, there is displayed on the cathode tube of a collimator an image comprising a circle of small size inside which there are, on the one hand, a horizon line inclined to the horizontal by an angle equal to but opposite the rolling angle of the aircraft, the horizon line being remote from the center of the circle by a distance which is a function of the pitching angle in the upward direction when the aircraft is diving and in the downward direction when the aircraft is pulling the nose up, and which delimits to zones of different brightness and, on the other hand, a point representing a pole situated on the median line of the horizon line at a distance from the latter corresponding to a pitching angle of 90.degree.. A "head up" type control system is essentially provided.

A method for encoding of words of an image memory designed to be read periodically to refresh an image formed on the screen by set of pixels wherein the image includes surfaces having a uniform color and demarcated by a contour having a median line and the neighborhood of the median line including, on either side of this line, the pixels neighboring a pixel of the median line. The image further contains filar plotting features with one pixel of the screen being in a one to one correspondence with the memory cell containing a word and the reading of the current cell including at least a part of the information needed to write the corresponding pixel on the screen. The method involves recoding memory words in relation to the contours including not only the memory words related to the median lines of the contours but also the memory words related to the neighborhood of the contour. The code of each re-coded memory word includes two information bits concerning the circumstances of the writing of the recoded bits. These two bits enable the identification by the combination of four different possible values.

A solid state attitude and director indicator (ADI) is disclosed utilizing liquid crystal display technology to represent attitude of a vehicle in two axes. A visual representation of attitude changes is provided on the liquid crystal display as well as numeric data, in a preferred embodiment. Additionally, glideslope, localizer, and approach speed may be displayed as well as heading and command bar information.

According to a process for representing information for guiding the flight of an aircraft, the airspace with at least one horizon and the precalculated flight path of the aircraft are three-dimensionally represented by means of animage display device and the surface above the horizon is subdivided into strips of different colours which extend parallel to the horizon. When the point of the precalculated flight path of the aircraft coincides with its shadow, the symbol that represents said precalculated flight path advantageously takes the position of the shadow projected on the ground. The shadow is preferably represented by a transparent design.

A flat panel display system for an aircraft display includes a graphics rendering computer for rendering of anti-aliased graphical imaging data derived from aircraft sensors for full-field imaging on a cockpit display screen. A comparator processor independently generates, from the same sensor data, a selected subset or "points of light" of the display screen image and compares the points of light data to the data generated by the rendering computer for the same display screen pixel locations. The minimized processing requirements and simplified design of the comparator processor enable ready FAA certification of the comparator processor, whereas the extreme complexity and processing operations required of the rendering computer make FAA certification thereof unusually time consuming and expensive. The comparator processor checks a meaningful subset of the imaging data generated by the rendering computer for each display refresh scan and thereby obviates the need for the otherwise-required level of rendering computer certification that is impractical or unavailable. The rendering computer may be implemented by commercial single-board personal computer hardware with a replaceable graphics processor to enable ease of use of improved components.