Spatial image content bandwidth requirements for synthetic vision displays

Synthetic Vision Systems (SVS) provide pilots with an unprecedented level of terrain awareness. Questions have been raised as to what level of resolution is needed for the raster based screen on which the terrain is shown. We conducted a flight simulator experiment where we systematically varied the pixel resolution of an SVS from 80 pixels per inch (PPI) to 120 PPI and determined pilot performance in terms of cross track error (XTE) when flying with sole reference to terrain. We then conducted a Fast Fourier Transform (FFT) analysis of the SVS images under the various levels of pixel resolution to determine how spatial image content could be correlated to pilot performance (XTE). We found that the log image amplitude correlated well with XTE and we propose a method wherein we may be able to predict pilot performance based on terrain image content. The method shown in this paper will allow display designers to harmonize the visual spatial bandwidth requirements of pilots with the bandwidth provided by the SVS images.