Altitude Processing in the ATCRBS

Equipment to process and display beacon-derived altitude information is being developed to enhance the operational capability of the Air Traffic Control Radar Beacon System (ATCRBS). Beacon identity and altitude information assists the air traffic controller to establish positive identification quickly and reliably; radar handoff procedures are completed more efficiently. The principle altitude functions of the beacon video processor under development are 1) To provide a digital display, in decimal form, of altitude data received from aircraft equipped with modified transponders which reply to a ground-to-air altitude interrogation. 2) To provide simultaneous altitude zone filtering of the altitude reply codes and tri-coordinate (3-D) radar data. 3) To provide altitude information to associated beacon video tracking units for aircraft tracking. The fully transistorized processor converts beacon video code trains from serial to parallel form. Leading edge decoding, pulse regeneration, pulse standardization, and destructive readout techniques are used to detect and eliminate spurious or garbled codes and to correctly process closely interleaved replies. Aircraft spaced as close as 344 feet in slant range are correctly read out. The equipment is designed for operation in either a computerizedor noncomputerized environment.