Two wavelength in-situ imaging of solitary internal waves
First Claim
1. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
- selectively generating short pulses of light having at least two different wavelengths;
projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water;
detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume, said pulses being detected using at least one gated camera means;
converting said detected pulses of light to two video images of said volume; and
subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
1 Assignment
0 Petitions
Accused Products
Abstract
A two wavelength lidar imaging system for underwater applications is presented which employs image subtraction. More specifically, a two wavelength lidar system is presented wherein two substantially simultaneously timed laser pulses of different wavelengths are emitted and are expanded by optics to illuminate the water below. A framing camera is then gated to receive light reflected or scattered back from the water. The light backscattered is filtered through narrow pass filters before it is recorded at the gated cameras. A specific application is disclosed in which the lidar imaging system is used to detect the passage of internal waves or other anomalies appearing in the ocean.
101 Citations
31 Claims
-
1. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume, said pulses being detected using at least one gated camera means; converting said detected pulses of light to two video images of said volume; and subtracting said two video images from one another to provide a video image of anomalies below the surface of the water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method of detecting and imaging internal waves below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume, said pulses being detected using at least one gated camera means; converting said detected pulses of light to two video images of said volume; and subtracting said two video images from one another to provide a video image of internal waves below the surface of the water.
-
-
10. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; gated camera means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; and subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting said detected pulses of light to two video images of said volume; subtracting said two video images from one another to provide a video image of anomalies below the surface of the water; and wherein said pulses of light are generated by a single laser pumped in series to define a pair of output pulses being spaced apart and being comprised of said two different wavelengths; and
whereinsaid reflected pair of output pulses being detected by two camera means.
-
-
20. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths, said pulses of light having two different wavelengths being generated simultaneously; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting said detected pulses of light to two video images of said volume; subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
21. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths, said pulses of light having two different wavelengths being spaced apart by a preselected time period; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting said detected pulses of light to two video images of said volume; subtracting said two video images from one another to provide a video image of anomalies below the surface of the water. - View Dependent Claims (22)
-
-
23. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths wherein one of the different wavelengths is the wavelength corresponding to the hingepoint and the other wavelength is a wavelength below the Jerlov minimum; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting said detected pulses of light to two video images of said volume; subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
24. A method of detecting and imaging anomalies below the surface of a body of water including the steps of:
-
selectively generating short pulses of light having at least two different wavelengths wherein the two different wavelengths are located on either side of the Jerlov minimum; projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting said detected pulses of light to two video images of said volume; subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
25. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water; wherein said generating means comprises a single laser pumped in series to define a pair of output pulses being spaced apart and being comprised of said two different wavelengths; and said detecting means comprises two camera means.
-
-
26. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths, said generating means generating said pulses of light having two different wavelengths simultaneously; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
27. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths, said generating means generating said pulses of light having two different wavelengths by a preselected spaced apart time period; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water. - View Dependent Claims (28)
-
-
29. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths wherein one of the different wavelengths is the wavelength corresponding to the hingepoint and the other wavelength is a wavelength below the Jerlov minimum; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
30. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths wherein the two different wavelengths are located on either side of the Jerlov minimum; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
-
31. An apparatus for detecting and imaging anomalies below the surface of a body of water comprising:
-
generating means for selectively generating short pulses of light having at least two different wavelengths; projecting means for projecting said short pulses of two different wavelengths of light toward the water and at a selected volume within the water; detecting means for detecting said pulses of two different wavelengths of light reflected back from said volume after a time delay corresponding to the round-trip propagation time of said light pulses to and from said volume; notch filter means for receiving said reflected light pulses and passing said pulses to said detecting means; converting means for converting said detected pulses of light to two video images of said volume; subtracting means for subtracting said two video images from one another to provide a video image of anomalies below the surface of the water.
-
Specification