Adaptive surface meshing and multiresolution terrain depiction for SVS
Thorsten Wiesemann, Jens Schiefele, Wolfgang Kubbat · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
Many of today's and tomorrow's aviation applications demand accurate and reliable digital terrain elevation databases. Particularly future Vertical Cut Displays or 3D Synthetic Vision Systems (SVS) require accurate and hi-resolution data to offer a reliable terrain depiction. On the other hand, optimized or reduced terrain models are necessary to ensure real-time rendering and computing performance. In this paper a new method for adaptive terrain meshing and depiction for SVS is presented. The initial data set is decomposed by using a wavelet transform. By examining the wavelet coefficients, an adaptive surface approximation for various Level-of-Detail is determined. Additionally, the dyadic scaling of the wavelet 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. The proposed terrain representation is integrated into a standard navigation display. Due to the multi-resolution data organization, terrain depiction e.g. resolution is adaptive to a selected zooming level or flight phase. Moreover, the wavelet decomposition helps to define local regions of interest. A depicted terrain resolution has a finer grain nearby the current airplane position and gets coarser with increasing aircraft distance. In addition, flight critical regions can be depicted in a higher resolution.