Donald M Leonard

US Patent:

47704829, Sep 13, 1988

Filed:

Jul 17, 1988

Appl. No.:

6/886464

Inventors:

Harold E. Sweeney - Menlo Park CA
Donald A. Leonard - Cupertino CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G02B 600
F41G 700

US Classification:

350 9610

Abstract:

A system for rapidly scanning a remote field of regard with transmitter laser beams comprises an optical system having a focal plane, a plurality of lasers capable of being sequentially fired, and a like number of optical fibers coupled at one end to the respective laser outputs. The opposite fiber ends lie in the focal plane of the optical system and are aligned in the direction of the height of the field of regard. The beams move rapidly across the width of the field of regard simultaneously with sequential operation of the lasers, thus illuminating the entire area of interest in a minimum of time.

US Patent:

49866567, Jan 22, 1991

Filed:

Nov 30, 1989

Appl. No.:

7/443679

Inventors:

Harold E. Sweeney - Menlo Park CA
Paul J. Titterton - Palo Alto CA
Donald A. Leonard - Cupertino CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G01N 2100
G01J 344

US Classification:

356 73

Abstract:

A method of remotely measuring the diffuse attenuation coefficient K of ocean water from an airborne platform such as an aircraft. By directing a pulsed laser beam having a wavelength. lambda. sub. 0 from the platform into the water, the beam interacts therewith to produce inelastic Brillouin backscatter signals at the wavelength. lambda. sub. 1, where. lambda. sub. 1. noteq. lambda. sub. The desired backscatter propagate generally oppositely to the direction of propagation of the pulsed laser beam so that the backscatter can be received and collected at the platform. The upwelling optical energy includes the desired backscatter signals, which are separated out from the remainder of the upwelling optical energy. The separated backscatter signals are converted to equivalent electrical signals and periodically analyzed to generate therefrom the diffuse attenuation coefficient of the ocean water at the. lambda. sub. 1 wavelength at periodic depths beneath the water surface.

US Patent:

61375667, Oct 24, 2000

Filed:

Feb 24, 1999

Appl. No.:

9/256942

Inventors:

Donald Leonard - Cupertino CA
Thomas Driscoll - Sunnyvale CA
Harold Sweeney - Menlo Park CA
Jay Bolstad - Sunnyvale CA
David Schultz - Mt. View CA

Assignee:

EOO, Inc. - Sunnyvale CA

International Classification:

G01B 1126
G01C 308
G01C 2124
H01L 2700

US Classification:

3561411

Abstract:

An apparatus for receiving signals from a photodetector in a photodetector array. The apparatus has a number of comparators (e. g. 5) connected to the photodetector. each photodetector in the array has a similar circuit connected. Each comparator compares the output of the photodetector with an adjustable threshold level. Each threshold level is controlled by a threshold controller. Each threshold level corresponds with a light intensity value. Outputs of the comparators are each connected to a shift register. Each shift register is triggered to sample the output of its associated comparator at a certain speed (e. g. 800 Mhz). In operation, the shift registers each store a bit sequence representative of the comparator output. The data acquired is used to adjust the threshold levels applied to the comparators. In this way, adjustable intensity resolution is provided at desired ranges of intensity.

US Patent:

48939242, Jan 16, 1990

Filed:

Jul 20, 1988

Appl. No.:

7/222598

Inventors:

Donald A. Leonard - Cupertino CA
Harold E. Sweeney - Menlo Park CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G01J 500

US Classification:

356 43

Abstract:

Subsurface waves in an ocean are created by the turbulence in a submarine's wake. These waves can be remotely detected by a search submarine by monitoring subsurface water temperatures using a laser. A pulsed laser beam is directed into the water to at least the depth of the thermocline and an analysis is made of the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water, and the frequency of the heterodyne signal is measured and converted into equivalent temperature values. This produces the desired temperature-depth profile of the water enabling detection of the first submarine by tracking the internal waves at or near the ocean thermocline.

US Patent:

52967115, Mar 22, 1994

Filed:

Nov 5, 1992

Appl. No.:

7/971872

Inventors:

Donald A. Leonard - Cupertino CA
Harold E. Sweeney - Menlo Park CA

Assignee:

Atlantic Richfield Company - Los Angeles CA

International Classification:

G01N 2165

US Classification:

250372

Abstract:

A method and apparatus for remote detection of an oil slick at or near the surface of the water using a combination of two or more ultraviolet lasers and comparing the relative magnitude of the received Raman backscattering signal magnitudes to determine the existence of the oil slick. The use of two different laser frequencies provides for elimination of atmospheric transmission variations and wave modulation.

US Patent:

50269992, Jun 25, 1991

Filed:

Apr 9, 1990

Appl. No.:

7/506304

Inventors:

Donald A. Leonard - Cupertino CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G01J 548
G01J 344

US Classification:

250574

Abstract:

A technique for measuring the unknown subsurface temperature T of a bulk transparent medium such as sea water by focussing a high intensity pulsed laser beam in a first direction into the water to a predetermined depth D, producing stimulated Brillouin scattering (SBS) in a second direction opposite to the first direction and generating from the SBS stimulated Raman scattering (SRS) in the second direction, analyzing the spectra of the SRS and determining therefrom the temperature T. The depth D is is selected to insure that the entire SBS pulse is in the water.

US Patent:

49738534, Nov 27, 1990

Filed:

Jul 28, 1989

Appl. No.:

7/386383

Inventors:

Donald A. Leonard - Cupertino CA
Harold E. Sweeney - Menlo Park CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G01N 1506
G01J 500
G01B 902

US Classification:

250574

Abstract:

Apparatus for measuring the unknown subsurface temperature T. sub. s of a bulk transparent medium such as ocean water comprises a pulsed laser having a high intensity (power per unit area) output beam split into two sub-beams, one of which is a probe beam directed into the ocean water. The intensity of the output beam pulses exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering within the medium and to produce therefrom a phase-conjugate beam which propagates along the path of the first sub-beam but in the opposite direction. The second sub-beam is reflected by a mirror to and combines with the PC beam and the combined beams are mixed at the cathode of a photodetector which produces a heterodyne frequency that is proportional to the temperature T. sub. s. A frequency measuring instrument converts the heterodyne frequency into a temperature value equal to T. sub. s.

US Patent:

50095005, Apr 23, 1991

Filed:

Jul 28, 1989

Appl. No.:

7/386382

Inventors:

Donald A. Leonard - Cupertino CA
Harold E. Sweeney - Menlo Park CA

Assignee:

GTE Government Systems Corporation - Stamford CT

International Classification:

G01B 902

US Classification:

356 43

Abstract:

A technique for measuring the unknown subsurface temperature T. sub. s of a bulk transparent medium such as ocean water by splitting a pulsed laser beam having a high intensity into two sub-beams, one of which is a probe beam directed into the medium. The intensity of the output beam pulses exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering within the medium and to produce therefrom a phase-conjugate beam which propagates along the path of the first sub-beam but in the opposite direction. The second sub-beam combines with the PC beam and the combined beams mix at the cathode of a photodetector thereby producing a heterodyne frequency proportional to the temperature T. sub. s. Converts the heterodyne frequency into a temperature value yields the desired unknown T. sub. s.