Claims
- 1. A method of detecting a substance, comprising the steps of:
deceiving radiation passing along a sample path of interest; dividing said radiation into a time series of alternating first polarized components and second polarized components orthogonal to said first polarized components; transmitting said first polarized components along a first optical path and said second polarized components along a second optical path; filtering said first polarized components to isolate at least a first wavelength band wherein first filtered radiation is generated; filtering said second polarized components to isolate at least a second wavelength band wherein second filtered radiation is generated, wherein said first wavelength band and said second wavelength band are unique and wherein spectral absorption of a substance of interest is different at said first wavelength band as compared to said second wavelength band; combining said first filtered radiation and said second filtered radiation to form a combined beam of radiation; and monitoring magnitude of said combined beam alternately at said first wavelength band and said second wavelength band as an indication of the concentration of said substance in said sample path:
- 2. A method according to claim 1 wherein said step of filtering said first polarized components comprises the step of passing only said first wavelength band to form said first filtered radiation, and wherein said step of filtering said second polarized components comprises the step of passing only said second wavelength band to form said second filtered radiation.
- 3. A method according to claim 1 wherein said step of filtering said first polarized components comprises the step of passing all wavelengths except said first wavelength band to form said first filtered radiation, and wherein said step of filtering said second polarized components comprises the step of passing all wavelengths except said second wavelength band to form said second filtered radiation.
- 4. A method according to claim 3 further comprising the step of performing gas filter correlation radiometry using one of said first polarized components and said first filtered radiation, and using one of said second polarized components and said second filtered radiation.
- 5. A method according to claim 1 wherein said step of filtering said first polarized components comprises the step of isolating a plurality of unique first wavelength bands, and wherein said step of filtering said second polarized components comprises the step of isolating a plurality of unique second wavelength bands, said method further comprising the step of:
partitioning said combined beam into a plurality of partitioned beams, each of said plurality of partitioned beams including one of said plurality of unique first wavelength bands and one of said plurality of unique second wavelength bands, wherein spectral absorption of a substance of interest is different at one of said one of said plurality of unique first wavelength bands as compared to said one of said plurality of unique second wavelength bands, wherein said step of monitoring comprises the step of monitoring magnitude of each of said plurality of partitioned beams.
- 6. A method according to claim 1 wherein a plurality of related substances of interest are spectrally absorbed more at said first wavelength band than at said second wavelength band.
- 7. A method according to claim 6 wherein said plurality of related substances are hydrocarbons.
- 8. A method according to claim 1 wherein said first polarized components are vertically polarized and said second polarized components are horizontally polarized.
- 9. A method according to claim 1 wherein said step of monitoring is harmonically synchronized to a frequency at which said time series alternates between said first polarized components and said second polarized components.
CLAIM OF BENEFIT OF PROVISIONAL APPLICATION
[0001] This application is a divisional patent application of commonly owned, co-pending patent application Ser. No. 09/290,954, filed Apr. 13, 1999.
[0002] Pursuant to 35 U.S.C. Section 119, the benefit of priority from provisional application 60/082,355, with a filing date of Apr. 20, 1998, is claimed for this non-provisional application.
ORIGIN OF THE INVENTION
[0003] The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60082355 |
Apr 1998 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09290954 |
Apr 1999 |
US |
Child |
09437616 |
Nov 1999 |
US |