AIRPORT GROUND SURVEILLANCE SYSTEM

• US 3,872,474 A
• Filed: 01/02/1973
• Issued: 03/18/1975
• Est. Priority Date: 01/02/1973
• Status: Expired due to Term

• Current Assignee: ITT Corporation (ITT, Inc.)
• Original Assignee: Arnold M. Levine
• Inventors: Levine, Arnold M.
• Primary Examiner(s): Hubler, Malcolm F.
• Application Number:
  US05/320,089
• Time in Patent Office: 805 Days
• Field of Search: 343/5PD,5LS,6TV,6A
• US Class Current: 342/36
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/913 for landing purposes

Abstract

A system for detecting, monitoring the movements of, and controlling the travel of aircraft and other vehicles on an airport surface. A series of small low-powered radar transmitreceive devices, each having a limited range, is disposed essentially in a line along alternate and opposite sides of a runway, ramp or taxiway. Control pulses at a system PRF travelling down the inter-connecting cables serve to cause the individual radars to '"'"''"'"''"'"''"'"'blink'"'"''"'"''"'"''"'"' in sequence in accordance with the inherent delay in the inter-connecting cable. Frequency separation is used to prevent false indications due to transmitreceive inter-action among the individual miniature radars. The system is adapted to data presentation in accordance with standard radar display techniques, or alternatively, a display is provided on a synthesized map of the airport. A pulse delay discriminator arrangement provides for discrete lateral position control. Means are also shown for televising the ground display to a vehicle on the surface and for providing discrete information such as a STOP order, etc.

Claims

1. A system for airport surface traffic control on at least one runway, comprising:

a plurality of low-power pulsed transmit-receive radar devices spaced along a line parallel to and laterally offset from said runway, each of said devices having a transmit-receive pattern extending over a discrete portion of said runway and each being responsive to timing pulses to transmit corresponding short microwave pulses contemporaneously;

a timing pulse generator for generating timing pulses of a first polarity at a predetermined PRF;

transmission line means connected from said pulse timing generator to supply said pulses to said radar devices serially in a predetermined order, the time of arrival of said timing pulses at each of said radar devices being determined by the length of said transmission line Thereto from said timing pulse generator;

reception means within each of said radar devices for receiving echo signals corresponding to said microwave pulses and for sending said echo signals in a second polarity into said transmission line; and

display means connected to said transmission line at a point removed from said radar devices and connected to be synchronized by said timing pulse generator and to visually display the positional data represented by said echo signals.

2. Apparatus according to claim 1 further defined in that each of said radar devices transmits and receives on a frequency separated from any other of said radar devices having a radiation pattern at least partially overlapping its own radiation pattern.

3. The invention according to claim 1 in which said radar devices are spaced along lines parallel to and laterally offset from each side of said runway being spaced by equal increments measured along said lines parallel to said runway on each side thereof, said radar devices further being staggered so that each is located at a position substantially equi-distant from the nearest two radar devices on the opposite side of said runway and said transmission line being arranged such that said radar devices transmit corresponding pulses alternately from both sides of said runway in order of increasing distance along the centerline of said runway.

4. Apparatus according to claim 3 in which said reception means includes means responsive to said timing pulses for enabling reception of said echo signals substantially only within a range gate corresponding to a predetermined lateral distance with respect to said runway.

5. Apparatus according to claim 4 in which said range gate corresponds substantially to the width of said runway.

6. Apparatus according to claim 4 in which said display means comprises a sequenced cathode ray display.

7. Apparatus according to claim 4 in which said display means comprises a plurality of light emitting diodes arranged in a map-like pattern in which each resolution element in the general direction of said runway and laterally thereto is represented by a discrete one of said light emitting diodes;

said display means comprises delay means having a plurality of outputs, each of which corresponds to one of said light emitting diodes, each of said delay means outputs providing pulses representative of the time position within the interval between successive ones of said timing pulses of a discrete corresponding resolution element on said map-like pattern; and

means comprising a plurality of circuits responsive to said delay means outputs and said echo signals on said transmission lines for activating said light emitting diodes at positions corresponding to said echo signal corresponding time positions within said interval between successive timing pulses.

8. Apparatus according to claim 3 in which said radar devices each include a horn antenna directed toward said runway with the axis of said horn being substantially normal to the centerline of said runway, said horns being further defined as producing a radiation and reception pattern substantially confined to predetermined azimuth and elevation angles whereby said pattern for each of said radar devices partially overlaps that of the nearest two radar devices on the opposite runway side.

9. Apparatus according to claim 8 in which said radar devices each include an LSA transmitter and a fixed tuned receiver connected to said horn antenna through a circulator and each of said radar devices includes a terminal connected to said transmission line and two oppositely poled diodes connected thereto, one of said diodes forming a signal isolating connection to said transmitter responsive to said timing pulses of said first polarity and the other diode forming a signal isolation connection to send said echo signal from said receiver into said transmission line.