Software and algorithms development of perspective aircraft synthetic vision system prototype
This article describes the software development of Synthetic Vision System (SVS) prototype, which provides enhanced situational awareness for flight crew and decision making assistance during approach and landing phases of flight in partial or zero-vision flight conditions for prospective civil transport aircrafts. The SVS uses the current aircraft position relative to underlying surface and its map database (map size, map grid intervals Δ1 and Δ2, and Х, Y, Z coordinates of grid reference) as initial data. Navigation systems (NS) and terrain awareness early warning system (TAEWS) act as the sources of the above listed data. For 3 D visual representation of the available data, it is necessary to express the coded topographic data in terms of a set of geometric patterns. In an oversimplified case we can approximate the terrain region by a set of rectangular parallelepipeds with rectangle bases allocated between the adjacent DB mesh points, and their heights correspond to the values of maximum heights of terrain forming nodes. After recovery of operation region 3D model we should cut off back lines and planes. The z-buffer method is chosen to solve the set problem, due to its high priority from the viewpoint of SVS realization as a part of a transport aircraft on-board equipment and regard of display system architecture features. The result of SVS operation consists in generating a 3D image of an operation region terrain to display it on the main flight display together with other kinds of information in real time mode. Based on the proposed algorithm the software was developed. Simulation results confirm the adequacy and applicability of the proposed approach to improve the situational awareness of the crew during approach and landing phases of flight in partial or zero-vision flight conditions for civil transport aircrafts.