Multi-resolution terrain depiction on an embedded 2D/3D synthetic vision system☆

Many of todayʹs and tomorrowʹs aviation applications demand accurate and reliable digital terrain elevation databases. Particularly, to enhance a pilotʹs situation awareness with future 3D Synthetic Vision Systems (SVS), accurate, reliable, and hi-resolution terrain databases are required to offer a realistic and reliable terrain depiction. On the other hand, optimized or reduced terrain models are necessary to ensure real-time rendering and computing performance. s paper a method for adaptive terrain meshing and depiction for SVS is presented. The initial data set is decomposed by using a wavelet like transform, resulting in terrain coefficients and delta values to represent the terrain data in an optimized multi-resolution data structure. By examining the coefficients and delta values, an adaptive surface approximation for various Level-of-Detail is determined at runtime. Constraints for the Level-of-Detail approximation (like max. approximation error or degree of topography preservation) can be assigned and changed at runtime. This results in an adaptive terrain depiction suitable to the current operational SVS display requirements. onally, the dyadic scaling of the transform is used to build a hierarchical quad-tree representation for the terrain data. This representation enhances fast interactive computations and real-time rendering methods. lti-resolution terrain concept is integrated into a hi-level certifiable 2D/3D scene graph rendering system. It runs on an aviation certifiable embedded rendering graphics board. The optimized combination of multi-resolution terrain data, scene graph organization, and graphics board allows it to handle dynamically terrain models up to 3 arc second post spacing. The system and data processing acknowledges standard certification rules for terrain database requirements, aeronautical data processing and software development (DO-178B, DO-254, DO-200A, and DO-276).