PATENTSCOPE will be unavailable a few hours for maintenance reason on Tuesday 19.11.2019 at 4:00 PM CET
Search International and National Patent Collections
Some content of this application is unavailable at the moment.
If this situation persists, please contact us atFeedback&Contact
1. (WO2010080189) ABSOLUTE TIME ENCODED SEMI-ACTIVE LASER DESIGNATION
Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

I CLAIM:

1. A method for semi-active laser (SAL) designation of a target, comprising: providing synchronized clock signals to a receiver on a first platform and a designator on a second remote platform; communicating an absolute timing signal between the receiver and the designator indicating the arrival time of a reflected pulse-stream at the receiver; transmitting a pulse-stream including at least one pulse from the designator towards the target; gating the returns from the target at the receiver within an absolute time window; using the absolute timing signal to synchronize the timing between the transmission of the laser pulse-stream and the gating of the returns to place the reflected pulse-stream in the absolute time window at the receiver; and processing the returns in the absolute time window to extract the pulse-stream to designate the target and verify the designator as the source of the pulse-stream.

2. The method of claim 1, wherein said laser pulse-stream includes only one pulse.

3. The method of claim 1, wherein placement of the reflected pulse stream in the absolute time window reduces the ambiguity of designator verification to less than a specified threshold, the number and relative spacing of pulses in the pulse stream being insufficient to reduce the ambiguity to less than the specified threshold but for the placement of the pulse-stream in the absolute time window.

4. The method of claim 1, wherein the number and relative spacing of pulses in the pulse stream and placement of the pulse-stream in the time window reduces the ambiguity of designator verification to less than a specified threshold.

5. The method of claim 1 , wherein the relative spacing of pulses in the pulse stream is known to both the designator and receiver.

6. The method of claim 1, wherein the pulse stream includes a plurality of pulses with a relative spacing known to both the designator and receiver, said receiver gating the returns to place each individual pulse in its own absolute time window.

7. The method of claim 6, wherein a path length from the designator to the target and back to the receiver is measured to shift the placement of the absolute time window for each said pulse.

8. The method of claim 1, wherein the absolute time window accounts for the removal of path length error, further comprising: estimating the path length from the designator to the target and back to the receiver; and augmenting the absolute timing signal to shift the placement of the absolute time window for the estimated path length.

9. The method of claim 8, further comprising setting the absolute time window a priori to account for the removal of path length error.

10. The method of claim 8, further comprising: setting the absolute time window to allow for path length error; and if the estimate of the path length is available, narrowing the absolute time window to remove path length error and shifting the placement of the narrowed absolute time window.

11. The method of claim 8, wherein the path length is estimated by geolocating said designator and said target and estimating the path length from the designator to the target.

12. The method of claim 11, wherein the same pulse-stream that is reflected off the target to the receiver is used to geolocate the target.

13. The method of claim 11, wherein the same pulse-stream that is reflected off the target to the receiver is used to estimate the path length from the designator to the target.

14. The method of claim 1, further comprising: measuring the absolute transmission time of the pulse-stream; relaying the absolute transmission time to the receiver; narrowing the absolute time window to remove transmission time error; and augmenting the absolute timing signal to shift the placement of the absolute time window to account for the absolute transmission time.

15. The method of claim 1, wherein the absolute timing signal is communicated between the designator and receiver by (a) the receiver sending the absolute timing signal to the designator indicating when to transmit the pulse-stream or when the absolute time window is open at the receiver, (b) the designator sending the absolute timing signal to the receiver indicating when the designator will transmit the pulse-stream, when the pulse-stream will reach the target or when the reflected pulse-stream will arrive at the receiver, or (c) a third remote platform sending the absolute timing signal to the designator and the receiver.

16. The method of claim 1, wherein the first platform also includes an autonomous guidance system for guiding the platform to the designated target.

17. The method of claim 1, wherein the pulse-stream is transmitted once.

18. The method of claim 17, wherein the receiver sends a verification signal back to the designator.

19. The method of claim 18, wherein if the verification signal is negative the pulse-stream is transmitted again in accordance with another absolute timing signal.

20. The method of claim 1, wherein the synchronized clock signals are provided by GPS.

21. The method of claim 1 , further comprising: slewing the second platform to point the designator and transmit a pulse-stream towards each of a plurality of targets in a time sequence; receiving the reflected pulse-streams at a respectively plurality of said receivers on different first platforms; synchronizing the timing between the designator's transmission of each said pulse-stream and each said receiver's gating of the returns off the different targets to place each said reflected pulse-stream in an absolute time window at the respective receiver.

22. The method of claim 21, further comprising: maneuvering each said first platform to orient the receiver to look for its target in a designated direction at the designated time.

23. A method for semi-active laser (SAL) designation of a target, comprising: providing synchronized clock signals to a receiver on a first platform and a designator on a second remote platform; communicating an absolute timing signal between the receiver and the designator indicating the arrival time of a reflected pulse-stream at the receiver in an absolute time window that accounts for the removal of path length uncertainty; estimating the path length from the designator to the target and back to the receiver; automatically transmitting a pulse-stream once from the designator towards the target, said pulse-stream including at least one pulse; gating the returns from the target at the receiver within the absolute time window; using the absolute timing signal and the path length to synchronize the timing between the transmission of the laser pulse-stream and the gating of the returns to place the reflected pulse-stream in the absolute time window at the receiver; and processing the returns in the absolute time window to extract the pulse-stream to designate the target and verify the designator as the source of the pulse-stream to less than a specified threshold, the number and relative spacing of pulses in the pulse stream being insufficient to reduce the ambiguity to less than the specified threshold but for the placement of the pulse-stream in the absolute time window.

24. The method of claim 23, wherein said laser pulse-stream includes only one pulse.

25. The method of claim 23, further comprising: setting the absolute time window to allow for path length error; and if the estimate of the path length is available, narrowing the absolute time window to remove path length error and shifting the placement of the narrowed absolute time window.

26. The method of claim 23, further comprising: sending a verification signal from the receiver to the designator; and if the verification signal is negative, retransmitting the pulse-stream in accordance with another absolute timing signal.

27. A system for semi-active laser (SAL) designation of a target, comprising: a designator on a remote first platform configured to visualize a target and transmit a pulse-stream including at least one pulse towards the target; a receiver on a second platform configured to gate the returns from the target within an absolute time window and process the returns to designate the target and verify the designator as the source of the pulse-stream; means for providing synchronized clock signals at the designator and receiver; and means for communicating an absolute timing signal between the receiver and the designator to place the reflected pulse-stream return in the absolute time window at the receiver.

28. The system of claim 27, wherein the designator is a single-shot laser capable of firing only a single pulse.

29. The system of claim 27, wherein the absolute time window accounts for the removal of path length error, further comprising means for estimating the path length from the designator to the target and back to the receiver, said receiver augmenting the absolute timing signal to shift the placement of the absolute time window for the estimated path length.

30. The system of claim 27, further comprising means for measuring the absolute transmission time of the pulse-stream and relaying the time to the receiver, said receiver narrowing the absolute time window to remove transmission time error and augmenting the absolute timing signal to shift the placement of the absolute time window to account for the absolute transmission time.

31. The system of claim 27, where said means for providing synchronized clocking signals comprises a GPS satellite network.

32. The system of claim 27, further comprising means for slewing the designator to transmit a pulse stream towards each of a plurality of targets in a time sequence for a respective plurality of receivers.

33. A precision guided weapons system for semi-active laser (SAL) designation of a target, comprising: a remote designator platform including a designator configured to visualize a target and transmit a pulse-stream including at least one pulse at the target; a weapon system platform including, a receiver configured to gate the returns from the target within an absolute time window and process the returns to designate the target and verify the designator as the source of the pulse-stream, and an autonomous guidance system for guiding the weapons system platform to the designated target;

means for providing synchronized clock signals at the designator and receiver; and means for communicating an absolute timing signal between the receiver and the designator to place the reflected pulse-stream return in the absolute time window at the receiver.