METHOD AND APPARATUS FOR HIGH SPEED VEHICLE POSITION ACQUISITION

• US 3,665,464 A
• Filed: 05/01/1969
• Issued: 05/23/1972
• Est. Priority Date: 05/01/1969
• Status: Expired due to Term

• Current Assignee: Loral Corporation (Newell Brands Inc.)
• Original Assignee: Willard C. Meilander
• Inventors: Meilander, Willard C.
• Primary Examiner(s): Hubler, Malcolm F.
• Application Number:
  US04/821,028
• Time in Patent Office: 1,118 Days
• Field of Search: 343/6.5,6.5LC,6.8,6.8LC,112TC
• US Class Current: 342/36
• CPC Class Codes: G01S 13/46 Indirect determination of position data
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

A transmitted interrogation and multiple receptions are utilized to provide aircraft position determination at high speed. A processing application of a data processor is utilized to implement the extensive data handling requirements of the system. The system may be ground based or is completely compatible with a navigational satellite or suitably equipped aircraft. Overlapped responses are substantially eliminated by discretely interrogating aircraft or other vehicles in accordance to distance.

Claims

1. A method to provide high speed target position information which includes the steps of a. providing a plurality of systems for detecting targets each covering a section of a predetermined overall area, b. effecting a general interrogation of all targets in the overall area through said systems, c. sending such known target information from each system to a data processing center, d. assigning each target to the system nearest to it, e. measuring the range of every target sent to the processing center with respect to a predetermined reference associated with the respective detecting system for the section in which the target is located, f. sequentially discretely interrogating each known target according to increasing range from said predetermined reference by the system covering the section in which each respective target is located until all known targets have been interrogated, g. interrogating for unknown targets, assigning them to systems and transferring targets moving from one system to the next, and h. repeating steps (b) through (g) as often as necessary to provide updated information on said known targets.

2. A high speed position acquisition system for moving vehicles which includes at least three antennae positioned with respect to the earth so that an angle is formed between the central antenna and those on each side thereof, the antennae being spaced at known distances of at least one-half mile relative to each other;

an interrogation transmitter designed to transmit a vehicle identification signal;

a receiver associated with each antenna to receive transmitted electromagnetic signals from each vehicle;

means to time the interrogation pulse from the interrogation transmitter;

an associative processor to receive and measure time of reply at each receiver to computer coordinate information for those signals with respect to a predetermined reference, the associative processor including means to provide sequential interrogation of each vehicle within the range of the interrogation transmitter, a memory bank to store information of each vehicle with respect to each antenna for each vehicle interrogated as a part of a word in memory, an arithmetic unit associated with each word in memory, and means to simultaneously insert respective range information for each antenna into the respective arithmetic unit for each word in memory sequentially for each antenna but simultaneously for all vehicles with respect to each antenna.

3. A system according to claim 2 where a sliding mask register is provided to achieve the simultaneoUs interrogation of each bit for all words in memory.

4. A high speed position acquisition system for moving vehicles which includes at least three antennae positioned with respect to the earth so that an angle is formed between the central antenna and those on each side thereof, the antennae being spaced at known distances of at least one-half mile relative to each other;

an interrogation transmitter designed to transmit a vehicle identification signal;

a receiver associated with each antenna to receive transmitted electromagnetic signals from each vehicle;

means to time the interrogation pulse from the interrogation transmitter;

means to receive and measure time of reply at each receiver to compute coordinate information for those signals with respect to a predetermined reference; and

control means to arrange all vehicles sequentially according to their range from a predetermined reference point within the perimeter defined by the antennae and to subsequently interrogate the vehicles according to the range, from nearest to furthest on all interrogations subsequent to the first.

5. A high seed position acquisition system for moving vehicles which comprises a transpondor in each vehicle, means to transmit a general interrogation signal to actuate the transmitters in the vehicles, means to receive the transmitted signals from the vehicles and compute range and altitude information thereof relative to a predetermined point, and means to sequentially interrogate the vehicles with a discrete signal in accordance with the vehicle range from the predetermined point beginning with the nearest vehicle, to prevent overlapping signals.

6. A method to provide vehicle position information for a plurality of vehicles which includes the steps of transmitting an identification signal for all vehicles within range, receiving a reply signal transmission for each vehicle in response to the identification signal at at least three separate antennae spaced at an angle with respect to each other, sending the reply signals to a common processor, computing coordinate position information for each vehicle in reference to a predetermined point within the perimeter defined by the antennae, based on the reply signals, arranging the vehicles in accordance with range with respect to said predetermined point as derived by the coordinate position information, and subsequently interrogating each individual vehicle by transmission in sequence at predetermined time intervals starting with the vehicle nearest said predetermined point and continuing according to increasing distance from said predetermined point.

7. A method according to claim 6 which includes computing whether any signal should be received at about the same time as a subsequent transmission, before each such transmission, and delaying such transmission by a short predetermined time interval when such overlap of receipt and transmission would occur.

8. A method according to claim 6 which includes repetition of the steps of claim 6 at very short intervals of time, the computations of position coordinates for all targets being accomplished simultaneously and followed by sequentially arranging the targets in range order.

9. A method according to claim 8 which includes interrogating, identifying, and determining range of all additional vehicles uninterrogated during the previous time interval, the additional vehicles being arranged in range sequential order along with the previously interrogated vehicles and interrogated in subsequent time intervals along with the previously interrogated vehicles.