A display system is provided that renders a horizontal situation indicator that includes required navigation performance (RNP) and estimated position uncertainty (EPU) values rendered non-numerically and in a fairly intuitive manner. A processor receives at least data representative of a desired course...http://www.google.com.hk/patents/US8155800?utm_source=gb-gplus-share專利 US8155800 - System for displaying required navigation performance on a horizontal situation indicator
