Patent ID: 8340837

Claim:
A method for enhancing air traffic routing visibility of certain chart symbols within an en-route chart symbol overlay on a terrain map display for an aircraft, said method comprising: representing, in a digital elevation model, each pixel of a terrain map display, the representation using a geographical location coordinate and an elevation associated with the location, each pixel further represented in the digital elevation model using at least one of a color value and a grayscale value; receiving a minimum elevation value for comparison with at least one of the pixels of the terrain map display, the minimum elevation value determined by a flight plan including a route of intended travel by the aircraft; setting the at least one of a color value and a grayscale value to a uniform value for all pixels in the digital elevation model where the elevation value associated with the pixel is less than the received minimum elevation value; displaying the visible terrain map display based on the set values in the digital elevation model such that pixels having a representation in the digital elevation model that includes the uniform value are displayed monochromatically; and overlaying the visible terrain map display pixels with the en-route chart symbol overlay, at least a portion of the chart symbols overlaid on the monochromatic portion of the terrain map such that the portion of the en-route chart symbols overlaid on the monochromatic portion of the terrain map are easily distinguishable to a user from the underlying pixels.