1. A computer implemented digital image processing method for conveying probabilities of observing lines of communication from an in-flight aircraft comprising the steps of: generating a geographical terrestrial map with lines of communications disposed thereon; receiving and storing input data defining an aircraft route relative to the geographical map; determining for segments of the lines of communication a visibility percentage that each of the segments will have line-of-sight visibility from the aircraft as the latter travels over its entire route; encoding the segments of the lines of communication with image differentiation to visually differentiate segments with visibility percentage greater than a first set value from segments with visibility percentage less than the first set value; providing a visual representation of the map with the image differentiated segments.