US3604803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical detection method for submerged objects
Assignee: Kollsman Instrument Corp
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Filing: 1969-03-03
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Granted: 1971-09-14
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Expires: 1989-03-03
Abstract
Abstract A submerged object indication system is carried from an aircraft flying above the water. A laser pulse generator directs a pulse at a small water area which may be 25 feet in diameter, and the receiver receives the air-water interface reflection which gates open a channel for receiving a submerged object reflection. A time delay is connected between an optical shutter and the detection circuit which receives the air-to-water interface reflection with the time delay related to the depth at which an object reflection is observed. The air-to-water interface signal can also be used to drive an altimeter with signals displayed visually on a cathode-ray tube display. The light source is in the blue-green portion of the spectrum, with the light pulse lengths being about 0.01 microseconds.
Inventors
- 👤 Elliott H Kahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:18
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/10; G01S17/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
134 words
A method for detecting from the air the position in the water of a submerged light reflecting object comprising the steps of beaming a pulse of light energy through the air towards a region of the air-water interface to produce in accordance with the angle of incidence a first reflected pulse that propagates through the air and a refracted pulse that propagates through the water to rebound from said object and produce a second reflected pulse that returns through said interface region and propagates through the air, directing an airborne receiver towards said region to pick up said first and second reflected pulses, initiating a timing cycle upon the arrival of said first reflected pulse at said receiver, and indicating the arrival of said second reflected pulse at said receiver during said timing cycle.
Claim 2
Independent Claim
134 words
A method for detecting from the air the position in the water of a submerged light reflecting object comprising the steps of beaming a pulse of light energy through the air towards a region of the air-water interface to produce in accordance with the angle of incidence a first reflected pulse that propagates through the air and a refracted pulse that propagates through the water to rebound from said object and produce a second reflected pulse that returns through said interface region and propagates through the air, directing an airborne receiver towards said region to pick up said first and second reflected pulses, initiating a timing cycle upon the arrival of said first reflected pulse at said receiver, and indicating the arrival of said second reflected pulse at said receiver during said timing cycle.
Claim 3
Dependent Claim
20 words
A method in accordance with claim 1 and wherein the beaming step comprises beaming a pulse of coherent light energy.
Claim 4
Dependent Claim
31 words
A method in accordance with claim 1 and wherein the beaming step comprises beaming a pulse of coherent light energy to span an interface region of about 25 feet in diameter.
Claim 5
Dependent Claim
40 words
A method in accordance with claim 1 and wherein the beaming step comprises beaming pulses at a predetermined repetition rate that defines a pulse interval that is long relative to the total travel time of a pulse to be indicated.
Claim 6
Dependent Claim
38 words
A method in accordance with claim 1 and wherein the beaming step comprises beaming a pulse of coherent light energy at the blue-green portion of the spectrum to span an interface region of about 25 feet in diameter.
Claim 7
Dependent Claim
27 words
A method in accordance with claim 5 and wherein the step of initiating a timing cycle includes gating the receiver to receive only said second reflected pulse.
Claim 8
Independent Claim
154 words
A method for detecting a submerged light reflecting object from a vehicle located above sea level by beaming light energy through the air towards a region of the air-water interface, comprising the steps of beaming a pulse of coherent light energy from the vehicle to produce in accordance with the angle of incidence a first reflected pulse of coherent light energy that propagates through the air and a refracted pulse of coherent light energy that propagates through the water to rebound from said object and produce a second reflected pulse of coherent light energy that returns through said interface region and propogates through the air, directing a receiver on said vehicle towards said region to pick up said first and second reflected pulses, initiating a timing cycle upon the arrival of said first reflected pulse at said receiver, and indicating the arrival of said second reflected pulse at said receiver during said timing cycle.
Claim 9
Independent Claim
154 words
A method for detecting a submerged light reflecting object from a vehicle located above sea level by beaming light energy through the air towards a region of the air-water interface, comprising the steps of beaming a pulse of coherent light energy from the vehicle to produce in accordance with the angle of incidence a first reflected pulse of coherent light energy that propagates through the air and a refracted pulse of coherent light energy that propagates through the water to rebound from said object and produce a second reflected pulse of coherent light energy that returns through said interface region and propogates through the air, directing a receiver on said vehicle towards said region to pick up said first and second reflected pulses, initiating a timing cycle upon the arrival of said first reflected pulse at said receiver, and indicating the arrival of said second reflected pulse at said receiver during said timing cycle.
Claim 10
Dependent Claim
59 words
A method in accordance with claim 7 and wherein the step of beaming a pulse of coherent light energy is controlled to provide a beam size at said interface optimized in relation to the distance from the vehicle to said region, optimized in relation to the interface surface conditions and optimized in relation to the size of the object.
Claim 11
Dependent Claim
40 words
A method in accordance with claim 8 and wherein the beaming stEp comprises beaming pulses at a repetition rate consistent with the coverage and depth of the region to be surveyed and of a duration of less than 30 nanoseconds.
Claim 12
Dependent Claim
30 words
A method in accordance with claim 9 and wherein the step of initiating a timing cycle includes controlling the response of the receiver to receive only said second reflected pulse.
References Cited (Backward Citations)
US3278753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |