Multiplatform system and method for ranging correction using spread spectrum ranging waveforms over a netted data link

• US 8,288,699 B2
• Filed: 11/03/2008
• Issued: 10/16/2012
• Est. Priority Date: 11/03/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Bielas, Michael S., Romero, Ric A.
• Primary Examiner(s): Gregory, Bernarr
• Application Number:
  US12/263,611
• Publication Number:
  US 20110224903A1
• Time in Patent Office: 1,443 Days
• Field of Search: 701/1, 701 23- 28, 701/200, 701/300, 701/301, 244 31- 319, 375130-153, 342 29- 58, 342 70- 72, 342/175, 342/195, 342450-465, 342 60- 65, 342/118, 342145-147
• US Class Current: 244/3.15
• CPC Class Codes: F41G 7/2206 using a remote control station
• CPC Class Codes: F41G 7/2233 Multimissile systems
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence

Abstract

Embodiments of a multiplatform system and method for ranging correction use spread-spectrum ranging waveforms over a netted data link. Each node may have a trajectory toward a target and may have a navigational error with respect to the trajectory. The nodes may transmit coded waveforms at one or more scheduled times for receipt by one or more of the other nodes during unused time slots on the netted data link. The nodes may correlate coded waveforms received from the other nodes to estimate a range to at least some of the other nodes. Each node may reset its navigational error and revise its trajectory based on the range estimates to the other nodes to avoid a possible collision with one or more of the other nodes.

Claims

1. A multiplatform system comprising a plurality of networked nodes that communicate over a netted data link, wherein at least some of the nodes are configured to:

transmit a coded waveform at one or more scheduled times for receipt by one or more of the other nodes;

correlate coded waveforms received from the other nodes to estimate a range to at least some of the other nodes, each node having a trajectory toward a target and a navigational error with respect to the trajectory;

revise the trajectory based on the range estimates to the other nodes to avoid a possible collision with one or more of the other nodes; and

reset the navigational error with respect to the revised trajectory.

2. The multiplatform system of claim 1

wherein the scheduled times are selected to occur during unused time-slots on the netted data link, and

wherein each node includes timing and scheduling circuitry configured to schedule transmission of a coded waveform at the one or more scheduled times during the unused time-slots.

3. The multiplatform system of claim 2 wherein at least some of the nodes are further configured to select a transmission schedule for transmission of the coded waveforms, the transmission schedule to provide an amount of overlap between the coded waveforms transmitted by the nodes ranging from a same-time transmission schedule that provides full overlap of the coded waveform transmissions, to a partial overlapping transmission schedule that provides a partial overlap of the coded waveform transmissions, to a sequential transmission schedule that provides no overlap of the coded waveform transmissions.

4. The multiplatform system of claim 3 wherein the transmission schedule is selected based on a number of nodes of the plurality and a length of the unused time-slots on the netted data link.

5. The multiplatform system of claim 4 wherein the transmission schedule is further selected based on a code length of a family of codes to be used for generating the coded waveforms.

6. The multiplatform system of claim 5 wherein the transmission schedule is selected to provide a lesser amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is greater, and

wherein the transmission schedule is selected to provide a greater amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is lower.

7. The multiplatform system of claim 6 wherein a family of codes having shorter lengths is selected when the multiplatform system includes a lesser number of nodes, and

wherein a family of codes having longer lengths is selected when the multiplatform system includes a greater number of nodes.

8. The multiplatform system of claim 3 wherein the transmission schedule is selected based on a channel quality of the netted data link.

9. The multiplatform system of claim 3 wherein the timing and scheduling circuitry of each node includes a clock, and

wherein the clocks of each node are synchronized prior to launch to provide for transmission of the coded waveforms at the one or more scheduled times in accordance with the selected transmission schedule.

10. The multiplatform system of claim 9 wherein the codes comprise pseudo-random codes of a family of related codes.

11. The multiplatform system of claim 10 wherein the coded waveforms are transmitted by the nodes at each of a plurality of scheduled times to allow each node to revise its trajectory and reset its navigational error on a regular basis.

12. The multiplatform system of claim 11 wherein a new set of codes of a selected family of codes is used to generate the coded waveforms for transmissions during each scheduled time.

13. The multiplatform system of claim 9 wherein the codes have a pseudo-random transec cover.

14. The multiplatform system of claim 2 wherein the netted data link comprises a network of data links established between the nodes to communicate data and telemetry with a master node,

wherein each of the nodes communicate information within designated time slots of the netted data link, and

wherein the nodes transmit the coded waveforms in accordance with the scheduled times during unused time slots of the netted data link.

15. A method for revising a trajectory and resetting a navigational error of a node operating in a multiplatform system comprising a plurality of nodes, the method comprising:

selecting a transmission schedule that identifies one or more scheduled times for transmission of a coded waveform;

transmitting the coded waveform in accordance with the transmission schedule for receipt by one or more of the other nodes;

correlating coded waveforms received from the other nodes to estimate a range to at least some of the other nodes, each node having a trajectory toward a target and a navigational error with respect to the trajectory; and

revising the trajectory based on the range estimates to the other nodes to avoid a possible collision with one or more of the other nodes; and

resetting the navigational error with respect to the revised trajectory.

16. The method of claim 15 wherein the nodes communicate over a netted data link,

wherein the scheduled times are selected to occur during unused time-slots on the netted data link, and

wherein the transmission schedule is selected to provide an amount of overlap between the coded waveforms transmitted by the nodes ranging from a same-time transmission schedule that provides full overlap of the coded waveform transmissions, to a partial overlapping transmission schedule that provides a partial overlap of the coded waveform transmissions, to a sequential transmission schedule that provides no overlap of the coded waveform transmissions.

17. The method of claim 16 further comprising selecting the transmission schedule based on a number of nodes of plurality and a length of the unused time-slots on the netted data link.

18. The method of claim 16 further comprising selecting the transmission schedule based on a channel quality of the netted data link.

19. The method of claim 16 further comprising selecting the transmission schedule based on a code length of a family of codes to be used for generating the coded waveforms.

20. The method of claim 19 wherein the transmission schedule is selected to provide a lesser amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is greater, and

wherein the transmission schedule is selected to provide a greater amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is lower.

21. The method of claim 20 further comprising:

selecting a family of codes having shorter lengths when the multiplatform system includes a lesser number of nodes; and

selecting a family of codes having longer lengths is selected when the multiplatform system includes a greater number of nodes.

22. A node configured to operate in a multiplatform system comprising a plurality of networked nodes that communicate over a netted data link, each node having a trajectory toward a target and a navigational error with respect to the trajectory, wherein the node comprises:

timing and scheduling circuitry to schedule transmission of a coded waveform at one or more scheduled times for receipt by one or more of the other nodes;

a parallel receiver to receive coded waveforms transmitted by one or more other nodes in accordance with a transmission schedule, the parallel receiver comprising a plurality of parallel correlators to correlate the coded waveforms received from the other nodes;

a range calculator to estimate a range to at least some of the other nodes based on the correlations; and

a navigational unit to revise the trajectory based on the range estimates to the other nodes to avoid a possible collision with one or more of the other nodes and to reset the navigational error with respect to the revised trajectory.

23. The node of claim 22 wherein each node further comprises a baseband modulator to modulate a selected code to generate a coded waveform at baseband for upconversion and transmission at the one or more scheduled times,

wherein the scheduled times are to occur during unused time-slots on the netted data link, and

wherein the timing and scheduling circuitry is configured to schedule transmission of a coded waveform at the one or more scheduled times during the unused time-slots.

24. The node of claim 22 wherein the transmission schedule is selected to provide an amount of overlap between the coded waveforms transmitted by the nodes of the plurality ranging from a same-time transmission schedule that provides full overlap of the coded waveform transmissions, to a partial overlapping transmission schedule that provides a partial overlap of the coded waveform transmissions, to a sequential transmission schedule that provides no overlap of the coded waveform transmissions.

25. The node of claim 24 wherein the transmission schedule is selected based on a number of nodes of plurality and a length of the unused time-slots on the netted data link.

26. The node of claim 24 wherein the transmission schedule is selected based on a channel quality of the netted data link.

27. The node of claim 24 wherein the transmission schedule is further selected based on a code length of a family of codes to be used for generating the coded waveforms.

28. The node of claim 27 wherein the transmission schedule is selected to provide a lesser amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is greater, and

wherein the transmission schedule is selected to provide a greater amount of overlap between the coded waveforms transmitted by the nodes when the number of nodes is lower.

29. The node of claim 27 wherein a family of codes having shorter lengths is selected when the multiplatform system includes a lesser number of nodes, and

wherein a family of codes having longer lengths is selected when the multiplatform system includes a greater number of nodes.