US3772525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Atmospheric transmissometer
Assignee: RTX Corp
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Filing: 1972-05-01
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Granted: 1973-11-13
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Expires: 1992-05-01
Abstract
Abstract A pair of corner reflectors have their reflective surfaces disposed to reflect light towards each other. A known percentage of light reflected from one reflector is reflected back towards the other reflector. A transmitter/receiver, disposed adjacent to one of the reflectors, transmits a light pulse towards the other reflector. Portions of two successive light pulses reflected from the other reflector are received by the transmitter/receiver. Apparatus responsive to the strengths of the two received light pulses provides a voltage related to the difference of the logarithms thereof, whereby a voltage is provided which is proportional to the atmospheric transmissibility of the medium between the reflectors.
Inventors
- 👤 R Goodwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:04
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/538
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
227 words
In the method of providing a signal proportional the transmissibility coefficient of light in a medium where pulses of light are transmitted between a single optical transmitter and a single optical receiver, the steps of: transmitting from said transmitter a transmitted light pulse over first and second paths within said medium, said first path being shorter than said second path; receiving at said single optical receiver, at a time commensurate with the time required for said light pulse to traverse said first path, a first received light pulse, which is part of said transmitted pulse, to establish a first light intensity related to the absorPtion and scattering of the transmitted light pulse in said medium between the times of transmitting said transmitted light pulse and receiving said first received pulse; subsequent to receiving said first received light pulse, receiving at said single optical receiver, at a time commensurate with the time required for said light pulse to traverse said second path, a second received pulse to establish a second light intensity related to the absorption and scattering of the transmitted light pulse in said medium between the times of transmitting said transmitted light pulse and receiving said second received light pulse; providing a transmissibility signal related to the ratio of said light intensities, said transmissibility signal being proportional to the transmissibility coefficient of light in said medium.
Claim 2
Dependent Claim
227 words
In the method of providing a signal proportional the transmissibility coefficient of light in a medium where pulses of light are transmitted between a single optical transmitter and a single optical receiver, the steps of: transmitting from said transmitter a transmitted light pulse over first and second paths within said medium, said first path being shorter than said second path; receiving at said single optical receiver, at a time commensurate with the time required for said light pulse to traverse said first path, a first received light pulse, which is part of said transmitted pulse, to establish a first light intensity related to the absorPtion and scattering of the transmitted light pulse in said medium between the times of transmitting said transmitted light pulse and receiving said first received pulse; subsequent to receiving said first received light pulse, receiving at said single optical receiver, at a time commensurate with the time required for said light pulse to traverse said second path, a second received pulse to establish a second light intensity related to the absorption and scattering of the transmitted light pulse in said medium between the times of transmitting said transmitted light pulse and receiving said second received light pulse; providing a transmissibility signal related to the ratio of said light intensities, said transmissibility signal being proportional to the transmissibility coefficient of light in said medium.
Claim 3
Dependent Claim
126 words
An atmospheric transmissometer for providing a transmissibility signal proportional to the optical transmissibility coefficient along first and second optical paths within a medium, said second path being longer than said first path, comprising: a single optical transmitting means for transmitting a single light pulse along both of said optical paths; a single optical receiving means for successively receiving through a single optical element light pulses transmitted by said transmitting means along both of said optical paths; processing means responsive to said single optical receiving means for providing a transmissibility signal related to the ratio of the respective intensities of light pulses successively received by said receiving means from respective ones of said optical paths, said transmissibility signal being proportional to said transmissibility coefficient within said medium.
Claim 4
Dependent Claim
126 words
An atmospheric transmissometer for providing a transmissibility signal proportional to the optical transmissibility coefficient along first and second optical paths within a medium, said second path being longer than said first path, comprising: a single optical transmitting means for transmitting a single light pulse along both of said optical paths; a single optical receiving means for successively receiving through a single optical element light pulses transmitted by said transmitting means along both of said optical paths; processing means responsive to said single optical receiving means for providing a transmissibility signal related to the ratio of the respective intensities of light pulses successively received by said receiving means from respective ones of said optical paths, said transmissibility signal being proportional to said transmissibility coefficient within said medium.
Claim 5
Dependent Claim
41 words
Apparatus according to claim 2 wherein said receiving means and said transmitting means comprise a single optical transmitter/receiver which both transmits and receives light pulses through a common optical element, and optical reflection means defining said first and second optical paths.
Claim 6
Dependent Claim
51 words
Apparatus according to claim 3 wherein said optical reflection means comprises first and second reflectors being disposed to reflect light from each to the other, said optical transmitter/receiver being disposed for transmitting light toward and receiving light from said first reflector, whereby said second optical path includes said first optical path.
Claim 7
Dependent Claim
38 words
Apparatus according to claim 4 wherein said second reflector is disposed adjacent to said transmitter/receiver, whereby said first optical path is one-half the length of said second optical path and said paths have substantially the same spacial location.
Claim 8
Dependent Claim
73 words
Apparatus according to claim 2 wherein said processing means comprises: logarithmic amplifier means responsive to said single optical receiving means for providing logarithm signals respectively proportional to the logarithms of the intensities of the received light pulses; storage means responsive to said logarithmic amplifier means for storing said logarithm signals; and means responsive to said storage means for providing said transmissibility signal as the difference of said stored logarithm signals plus a constant.
Claim 9
Dependent Claim
61 words
Apparatus according to claim 6 wherein said processing means additionally comprises timing means connected to said transmitting means and to said storage means for providing timing pulses and steering pulses respectively thereto, said transmitting means providing light pulses in response to said timing pulses, said storage means selectively storing successive ones of said logarithm signals in response to said steering pulses.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |