Data link and method

• US 5,835,059 A
• Filed: 09/01/1995
• Issued: 11/10/1998
• Est. Priority Date: 09/01/1995
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Nadel, Jesse H., Snape, Glenn R., Stevens, Peter F.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US08/522,642
• Time in Patent Office: 1,166 Days
• Field of Search: 342/398, 342/456, 342/37, 364/439
• US Class Current: 342/398
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile

Abstract

This is a Mode S radio frequency transmission system with coordinated use of a rotating directional antenna and omnidirectional antennas. A software-implemented prefilter both processes messages destined for aircraft equipped with Mode S datalink capable transponders, and prevents any uplink message transmission to a transponder from coinciding with the once-per-scan surveillance interrogation from the rotating antenna as well as any datalink interrogations specified for transmission through the rotating antenna.

Claims

1. A method for routing a message to either a rotating directional antenna or a nonrotating antenna, comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving a message which contains information designating an intended recipient of that message;

determining whether the intended recipient of the message is in the list of targets; and

if the intended recipient of the message is in the list of targets, then providing the message to a nonrotating antenna for transmission, otherwise providing the message to a rotating antenna for transmission.

2. Apparatus for routing a message to either a rotating directional antenna or a nonrotating antenna, comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving a message which contains information designating an intended recipient of that message;

means for determining whether the intended recipient of the message is in the list of targets; and

means for, if the intended recipient of the message is in the list of targets, then providing the message to a nonrotating antenna for transmission, otherwise providing the message to a rotating antenna for transmission.

3. A method for coordinating operation of a nonrotating antenna with operation of a rotating antenna having at least one beam of known width, to prevent the rotating antenna from interfering with the nonrotating antenna, comprising the steps of:

first determining the position of an intended recipient of a signal from the nonrotating antenna;

second determining whether the position of the intended recipient, as determined by said first determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the signal via the nonrotating antenna, otherwise storing the signal in a queue for reconsideration at a later time.

4. Apparatus for coordinating operation of a nonrotating antenna with operation of a rotating antenna having at least one beam of known width, to prevent the rotating antenna from interfering with the nonrotating antenna, comprising:

first determining means for determining the position of an intended recipient of a signal from the nonrotating antenna;

second determining means for determining whether the position of the intended recipient, as determined by said first determining means, is then within a beam of the rotating antenna; and

means for if not, then transmitting the signal via the nonrotating antenna, otherwise storing the signal in a queue for reconsideration at a later time.

5. A method for transmitting a signal via a rotating antenna or a nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving a message which contains information designating an intended recipient of that message;

first determining whether the intended recipient of the message is in the list of targets; and

if the intended recipient of the message is not in the list of targets, then providing the message to a rotating antenna for transmission;

if the intended recipient is in the list of targets, then second determining the position of the intended recipient of the message from the nonrotating antenna;

third determining whether the position of the intended recipient, as determined by said second determining steps is then within a beam of the rotating antenna; and

if not, then transmitting the message via the nonrotating antenna, otherwise storing the message in a queue for reconsideration at a later time.

6. Apparatus for transmitting a message via a rotating antenna or a nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving a message which contains information designating an intended recipient of that message;

first determining means for determining whether the intended recipient of the message is in the list of targets;

means for, if the intended recipient of the message is not in the list of targets, then providing the message to a rotating antenna for transmission;

second determining means for, if the intended recipient is in the list of targets, then determining the position of the intended recipient of the message from the nonrotating antenna;

third determining means for determining whether the position of the intended recipient, as determined by said second determining means, is then within a beam of the rotating antenna; and

if not, then transmitting the message via the nonrotating antenna, otherwise storing the message in a queue for reconsideration at a later time.

7. In a ground-based radar system including a rotating directional antenna and a nonrotating antenna, a method for routing a message to either the rotating directional antenna or the nonrotating antenna, comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving a message which contains information designating an intended recipient of that message;

determining whether the intended recipient of the message is in the list of targets; and

if the intended recipient of the message is in the list of targets, then providing the message to a nonrotating antenna for transmission, otherwise providing the message to a rotating antenna for transmission.

8. In a ground-based radar system including a rotating directional antenna and a nonrotating antenna, apparatus for routing a message to either the rotating directional antenna or the nonrotating antenna, comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving a message which contains information designating an intended recipient of that message;

means for determining whether the intended recipient of the message is in the list of targets; and

means for, if the intended recipient of the message is in the list of targets, then providing the message to a nonrotating antenna for transmission, otherwise providing the message to a rotating antenna for transmission.

9. In a ground-based radar system including a rotating antenna and a nonrotating antenna, a method for coordinating operation of the nonrotating antenna with operation of the rotating antenna to prevent the rotating antenna from interfering with the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

first determining the position of an intended recipient of a signal from the nonrotating antenna;

second determining whether the position of the intended recipient, as determined by said first determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the signal via the nonrotating antenna, otherwise storing the signal in a queue for reconsideration at a later time.

10. In a ground-based radar system including a rotating antenna and a nonrotating antenna, apparatus for coordinating operation of the nonrotating antenna with operation of the rotating antenna to prevent the rotating antenna from interfering with the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

first determining means for determining the position of an intended recipient of a signal from the nonrotating antenna;

second determining means for determining whether the position of the intended recipient, as determined by said first determining means, is then within a beam of the rotating antenna; and

means for if not, then transmitting the signal via the nonrotating antenna, otherwise storing the signal in a queue for reconsideration at a later time.

11. In a ground-based radar system including a rotating antenna and a nonrotating antenna, a method for transmitting a message via the rotating antenna or the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving a message which contains information designating an intended recipient of that message;

first determining whether the intended recipient of the message is in the list of targets; and

if the intended recipient of the message is not in the list of targets, then providing the message to a rotating antenna for transmission;

if the intended recipient is in the list of targets, then second determining the position of the intended recipient of the message from the nonrotating antenna;

third determining whether the position of the intended recipient, as determined by said second determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the message via the nonrotating antenna, otherwise storing the message in a queue for reconsideration at a later time.

12. In a ground-based radar system including a rotating antenna and a nonrotating antenna, apparatus for transmitting a message via the rotating antenna or the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving a message which contains information designating an intended recipient of that message;

first determining means for determining whether the intended recipient of the message is in the list of targets;

means for, if the intended recipient of the message is not in the list of targets, then providing the message to a rotating antenna for transmission;

second determining means for, if the intended recipient is in the list of targets, then determining the position of the intended recipient of the message from the nonrotating antenna;

third determining means for determining whether the position of the intended recipient, as determined by said second determining means, is then within a beam of the rotating antenna; and

if not, then transmitting the message via the nonrotating antenna, otherwise storing the message in a queue for reconsideration at a later time.

13. A method for routing digital data to either a rotating directional antenna or a nonrotating antenna, comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving digital data which contains information designating an intended recipient of that digital data;

determining whether the intended recipient of the digital data is in the list of targets; and

if the intended recipient of the digital data is in the list of targets, then providing the digital data to a nonrotating antenna for transmission, otherwise providing the digital data to a rotating antenna for transmission.

14. Apparatus for routing digital data to either a rotating directional antenna or a nonrotating antenna, comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving digital data which contains information designating an intended recipient of that digital data;

means for determining whether the intended recipient of the digital data is in the list of targets; and

means for, if the intended recipient of the digital data is in the list of targets, then providing the digital data to a nonrotating antenna for transmission, otherwise providing the digital data to a rotating antenna for transmission.

15. A method for coordinating operation of a nonrotating antenna with operation of a rotating antenna having at least one beam of known width, to prevent the rotating antenna from interfering with the nonrotating antenna, comprising the steps of:

first determining the position of an intended recipient of digital data from the nonrotating antenna;

second determining whether the position of the intended recipient, as determined by said first determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

16. Apparatus for coordinating operation of a nonrotating antenna with operation of a rotating antenna having at least one beam of known width, to prevent the rotating antenna from interfering with the nonrotating antenna, comprising:

first determining means for determining the position of an intended recipient of digital data from the nonrotating antenna;

second determining means for determining whether the position of the intended recipient, as determined by said first determining means, is then within a beam of the rotating antenna; and

means for if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

17. A method for transmitting digital data via a rotating antenna or a nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving digital data which contains information designating an intended recipient of that digital data;

first determining whether the intended recipient of the digital data is in the list of targets; and

if the intended recipient of the digital data is not in the list of targets, then providing the digital data to a rotating antenna for transmission;

if the intended recipient is in the list of targets, then second determining the position of the intended recipient of digital data from the nonrotating antenna;

third determining whether the position of the intended recipient, as determined by said second determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

18. Apparatus for transmitting digital data via a rotating antenna or a nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving digital data which contains information designating an intended recipient of that digital data;

first determining means for determining whether the intended recipient of the digital data is in the list of targets;

means for, if the intended recipient of the digital data is not in the list of targets, then providing the digital data to a rotating antenna for transmission;

second determining means for, if the intended recipient is in the list of targets, then determining the position of the intended recipient of digital data from the nonrotating antenna;

third determining means for determining whether the position of the intended recipient, as determined by said second determining means, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

19. In a ground-based radar system including a rotating directional antenna and a nonrotating antenna, a method for routing digital data to either the rotating directional antenna or the nonrotating antenna, comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving digital data which contains information designating an intended recipient of that digital data;

determining whether the intended recipient of the digital data is in the list of targets; and

if the intended recipient of the digital data is in the list of targets, then providing the digital data to a nonrotating antenna for transmission, otherwise providing the digital data to a rotating antenna for transmission.

20. In a ground-based radar system including a rotating directional antenna and a nonrotating antenna, apparatus for routing digital data to either the rotating directional antenna or the nonrotating antenna, comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving digital data which contains information designating an intended recipient of that digital data;

means for determining whether the intended recipient of the digital data is in the list of targets; and

means for, if the intended recipient of the digital data is in the list of targets, then providing the digital data to a nonrotating antenna for transmission, otherwise providing the digital data to a rotating antenna for transmission.

21. In a ground-based radar system including a one rotating antenna and a nonrotating antenna, a method for coordinating operation of the nonrotating antenna with operation of the rotating antenna to prevent the rotating antenna from interfering with the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

first determining the position of an intended recipient of digital data from the nonrotating antenna;

second determining whether the position of the intended recipient, as determined by said first determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

22. In a ground-based radar system including a rotating antenna and a nonrotating antenna, apparatus for coordinating operation of the nonrotating antenna with operation of the rotating antenna to prevent the rotating antenna from interfering with the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

first determining means for determining the position of an intended recipient of digital data from the nonrotating antenna;

second determining means for determining whether the position of the intended recipient, as determined by said first determining means, is then within a beam of the rotating antenna; and

means for if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

23. In a ground-based radar system including a rotating antenna and a nonrotating antenna, a method for transmitting a message via the rotating antenna or the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said method comprising the steps of:

establishing in a storage device a list of one or more targets for a nonrotating antenna;

receiving digital data which contains information designating an intended recipient of that digital data;

first determining whether the intended recipient of the digital data is in the list of targets; and

if the intended recipient of the digital data is not in the list of targets, then providing the digital data to a rotating antenna for transmission;

if the intended recipient is in the list of targets, then second determining the position of the intended recipient of digital data from the nonrotating antenna;

third determining whether the position of the intended recipient, as determined by said second determining step, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.

24. In a ground-based radar system including a rotating antenna and a nonrotating antenna, apparatus for transmitting digital data via the rotating antenna or the nonrotating antenna, wherein the rotating antenna has at least one beam of known width, said apparatus comprising:

means for establishing in a storage device a list of one or more targets for a nonrotating antenna;

means for receiving digital data which contains information designating an intended recipient of that digital data;

first determining means for determining whether the intended recipient of the digital data is in the list of targets;

means for, if the intended recipient of the digital data is not in the list of targets, then providing the digital data to a rotating antenna for transmission;

second determining means for, if the intended recipient of is in the list of targets, then determining the position of the intended recipient of digital data from the nonrotating antenna;

third determining means for determining whether the position of the intended recipient, as determined by said second determining means, is then within a beam of the rotating antenna; and

if not, then transmitting the digital data via the nonrotating antenna, otherwise storing the digital data in a queue for reconsideration at a later time.