Navigation aid for the blind. Blind man Reginald Golledge (right) and researcher Jack Loomis with the Personal Guidance System, an electronic navigation aid for blind people. The position of the user is determined by a GPS satellite receiver, and the direction in which they are facing by an electronic compass. These data are compared with a digital map in a computer, which calculates the position of landmarks relative to the user and synthesizes a word (eg 'Library') for each. These are fed into stereo earphones so the user can hear them coming from the correct relative locations. This system was developed at the University of California at Santa Barbara.