Visual environment simulator for mobile viewer

A visual environment simulator for a viewer moving about in a device implementation space. A display screen shows the viewer images of another environment. An array of three separately positioned ultrasonic transmitters sends intermittent signals to each of three ultrasonic receivers in order to monitor the change in the spatial coordinates and the orientation angles of the viewer and/or mobile unit(s) carrying or carried by the viewer. Digital circuitry is provided for sending and receiving sonic signals in a predetermined time sequence, and for sending a cue pulse to accurately initiate the counting of the transit time for each separate sonic signal. The transit time data are processed and revised video images are shown to correspond with the change of location (3-dimensional translational displacements) and change of orientation (3-axis rotational displacements) along and about the line-of-sight of the viewer.