초록 ▼

The system and method relate to detection of objects that are submerged, or partially submerged (e.g. floating), relative to a water surface. One aspect of the invention emits LIDAR fan-beam pulses and analyzes return-pulse portions to determine water-surface orientations and derive submerged-object

The system and method relate to detection of objects that are submerged, or partially submerged (e.g. floating), relative to a water surface. One aspect of the invention emits LIDAR fan-beam pulses and analyzes return-pulse portions to determine water-surface orientations and derive submerged-object images corrected for refractive distortion. Another defines simulated images of submerged objects as seen through waves in a water surface, prepares an algorithm for applying a three-dimensional image of the water surface in refractive correction of LIDAR imaging through waves—and also models application of the algorithm to the images, and finally specifies the LIDAR-system optics. Yet another emits nearly horizontal pulses to illuminate small exposed objects at tens of kilometers, detects reflected portions and images successive such portions with a streak-tube subsystem. Still others make special provisions for airborne objects.

대표청구항 ▼

What is claimed is: 1. A system for detecting, from an elevated position on a water craft that is in a body of water, discrete solid objects floating or submerged in said water, said objects being distinct from a bottom of the body of water; said system comprising: a LIDAR subsystem, mounted at suc

What is claimed is: 1. A system for detecting, from an elevated position on a water craft that is in a body of water, discrete solid objects floating or submerged in said water, said objects being distinct from a bottom of the body of water; said system comprising: a LIDAR subsystem, mounted at such elevated position on such water craft, above the top of such body of water, for emitting thin fan-beam light pulses at a shallow angle relative to horizontal, and for detecting reflected portions of the fan-beam pulses at a like shallow angle relative to horizontal; and means for determining disposition of the LIDAR subsystem and using the determined disposition in interpreting the detected pulse portions. 2. The system of claim 1, wherein: the disposition comprises position and orientation. 3. The system of claim 1, further comprising: means for determining geodetic localization of such objects. 4. The system of claim 1, for use with objects that are submerged at a range of depths less than ten meters; and wherein: the shallow angle is in a range between one and fifteen degrees. 5. The system of claim 1, for use with objects that are submerged at a range of depths less than ten meters; and wherein: the shallow angle is in a range between two and ten degrees. 6. The system of claim 1, for use with objects that are submerged at a range of depths less than ten meters; and wherein: the shallow angle is on the order of five degrees. 7. A system for detecting discrete solid objects floating or submerged near a water craft that is in a body of water, said objects being distinct from a bottom of the body of water; said system comprising: a LIDAR subsystem, mounted to the water craft at an elevated position thereof, for emitting thin fan-beam light pulses at a shallow angle relative to horizontal, and for detecting reflected portions of the fan-beam pulses at a like shallow angle relative to horizontal; and means for determining disposition of the LIDAR sub-system and using the determined disposition in interpreting the detected pulse portions. 8. The system of claim 7, further comprising: means for applying the detected pulse portions in determining geodetic localization of hazards associated with such objects. 9. A system for detecting floating or submerged objects near a water craft that is in a body of water, said objects being distinct from a bottom of said body of water; said system comprising: means, mounted to the water craft at an elevated position thereof, above the top of such body of water, for emitting thin fan-beam light pulses at a shallow angle relative to horizontal, and for detecting reflected portions of the fan-beam pulses at a like shallow angle relative to horizontal; and means for determining disposition of the emitting and detecting means and using the determined disposition in interpreting the detected pulse portions. 10. The system of claim 9, further comprising: means for applying the detected pulse portions in determining geodetic localization of such objects. 11. The system of claim 9, further comprising: means for controllably varying said angle of the emitting means. 12. The system of claim 11, wherein the varying means comprise: an adjustable mount, holding the emitting and detecting means in variable orientation. 13. The system of claim 12, wherein: the mount comprises means for holding the emitting and detecting means in variable orientation in at least two degrees of freedom. 14. The system of claim 12, wherein the mount comprises: a gimbal box. 15. The system of claim 11, further comprising: means for stabilizing the fan beam in a selected orientation; and means for servocontrolling the stabilizing means, based upon the determined disposition. 16. A system for detecting objects floating or submerged near a water craft that is in a body of water, said objects being distinct from a bottom of said body of water; said system comprising: a LIDAR subsystem, mounted to such craft, for emitting thin fan-beam light pulses toward such objects; means for imaging successive reflected fan-beam pulse portions in a way that tightly localizes reflection from a water surface near such objects; and means for determining disposition of the LIDAR subsystem and using the determined disposition in interpreting the imaged reflected pulse portions. 17. A system for detecting objects floating or submerged near a water craft in a body of water, said objects being distinct from a bottom of said body of water; said system comprising: means, mounted to such craft above the top of such body of water, for emitting thin fan-beam light pulses toward such objects; means for imaging successive reflected fan-beam pulse portions in a way that tightly localizes reflection from a water surface near such objects; and means for determining disposition of the emitting means and using the determined disposition in interpreting the imaged reflected pulse portions. 18. The system of claim 17, further comprising: means for applying the interpreted pulse portions in determining geodetic localization of such objects. 19. A systems, mounted on a water craft, for detecting discrete solid objects floating or submerged in a body of water, said objects being distinct from a bottom of the body of water; said system comprising: a first subsystem, mounted at an elevated position of such water craft, for emitting a series of light pulses; a second subsystem, mounted to such water craft, for time resolving and interpreting reflected portions of the pulses; and means for determining disposition of the first or second subsystem, or both, and using the determined disposition or dispositions in interpreting the time-resolved reflected pulse portions. 20. The system of claim 19, further comprising: means for controllably varying orientation of at least the first subsystem. 21. The system of claim 20, wherein the varying means comprise: an adjustable mount, holding at least the first subsystem in variable orientation. 22. The system of claim 21, wherein: the mount comprises means for holding at least the first subsystem in variable orientation in at least two degrees of freedom. 23. The system of claim 19: wherein the pulses are in the form of a thin fan-beam; further comprising a gimbal box for holding at least the first subsystem in a variable orientation; and means for servocontrolling the gimbal box to hold the fan-beam parallel to the horizon. 24. The system of claim 19, further comprising: means for stabilizing at least the first subsystem in a selected orientation; and means for servocontrolling the stabilizing means, based upon the determined disposition or dispositions.