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EP-4735866-A1 - SYSTEMS AND METHODS FOR SPATIO-TEMPORAL ANALYTE MEASUREMENTS OVER A FIELD USING AN OPTICAL WEB

EP4735866A1EP 4735866 A1EP4735866 A1EP 4735866A1EP-4735866-A1

Abstract

Systems and methods are provided for measuring analytes (e.g., greenhouse gases, such as nitrous oxide) in the air over a field or other area. An optical web can be cast over the field, using a laser respectively provided from each of two or more towers disposed around an edge of the field, for the estimation of flux emissions and their spatiotemporal parameters. Each laser can be configured to provide light at a respective predetermined wavelength to one or more reflectors disposed around an edge of the field, providing a path integrated measurement, and then the light returns from the reflector to a detector that is coaligned with each respective laser. By making many such measurements, a set of linear equations can be generated, which can then be used to solve for the emission in any one grid cell of the field.

Inventors

  • ZONDLO, Mark
  • SEVOSTIANOV, Vladislav
  • GUIGUIZIAN, Paul
  • COLLINS, JOSH
  • LI, Nathan
  • TAO, LEI

Assignees

  • The Trustees of Princeton University

Dates

Publication Date
20260506
Application Date
20240627

Claims (20)

  1. 1. A system for measuring at least one analyte in air over a field, the system comprising: a first tower and a second tower each disposed at or near a perimeter of the field, wherein each of the first tower and the second tower comprises at least one mid-infrared (mid-IR) light source disposed thereon and configured to provide light at a predetermined wavelength for a particular analyte, wherein the predetermined wavelength is in a range of from 2 micrometers (pm) to 30 pm; a plurality of reflectors disposed around the perimeter of the field and configured to reflect light from the mid-IR light source of each of the first tower and the second tower; and an analyzer unit in operable communication with the at least one mid-IR light source of each tower of the at least one tower.
  2. 2. The system according to claim 1, wherein each of the first tower and the second tower further comprises a first detector disposed thereon and configured to receive signals of light reflected from the plurality of reflectors.
  3. 3. The system according to any of claims 1-2, further comprising a meteorology station in operable communication with the analyzer unit, wherein the meteorological station is configured to obtain meteorological data of the air over the field, air adjacent to the field, or both.
  4. 4. The system according to claim 3, wherein the meteorological data comprises wind speed, wind direction, air pressure, air temperature, humidity, or a combination thereof.
  5. 5. The system according to any of claims 3-4, wherein the meteorology station is disposed within or adjacent to the field.
  6. 6. The system according to any of claims 1-5, wherein each analyte of the at least one analyte is a greenhouse gas or air pollutant.
  7. 7. The system according to claim 6, wherein the at least one analyte comprises nitrous oxide (N2O), ammonia (NH3), methane (CH4), carbon dioxide (CO2), or a combination thereof.
  8. 8. The system according to any of claims 1-7, wherein the system is configured to measure the at least one analyte with a sensitivity of 100 parts per billion (ppb) or less.
  9. 9. The system according to claim 8, wherein the system is configured to measure the at least one analyte with a sensitivity of 10 ppb or less.
  10. 10. The system according to any of claims 8-9, wherein the system is configured to measure the at least one analyte with a sensitivity of 1 ppb or less.
  11. 11. The system according to any of claims 1-10, wherein the plurality of reflectors are disposed at regular intervals around the perimeter of the field.
  12. 12. The system according to any of claims 1-11, wherein the plurality of reflectors are disposed close enough to each other around the perimeter of the field the analyzer unit to generate a map of a concentration of the at least one analyte with a predetermined granularity.
  13. 13. The system according to claim 12, wherein the analyzer unit comprises software stored thereon that is configured to receive the signals of light reflected from the plurality of reflectors and convert them to data indicative of a concentration of the at least one analyte in the air.
  14. 14. The system according to claim 13, wherein the analyzer unit converts the signals via wavelength modulation spectroscopy, direct absorption spectroscopy, or both.
  15. 15. The system according to any of claims 13-14, wherein the data indicative of the concentration of the at least one analyte in the air comprises at least one of: spatial information of the concentration of the at least one analyte in the air; vertical profile information of the concentration of the at least one analyte in the air; and a flux of the concentration of the at least one analyte in the air.
  16. 16. The system according to any of claims 13-15, further comprising a display in operable communication with the analyzer unit, wherein the analyzer unit is configured to display the data indicative of the concentration of the at least one analyte in the air on the display.
  17. 17. The system according to any of claims 1-16, wherein each reflector of the plurality of reflectors is a retroreflector configured to reflect mid-IR light.
  18. 18. The system according to claim 17, wherein the retroreflector comprises a base substrate and a coating layer disposed on the base substrate.
  19. 19. The system according to claim 18, wherein the retroreflector further comprises at least one of: an adhesive layer disposed between the base substrate and the coating layer; a protective layer disposed on the coating layer.
  20. 20. The system according to claim 19, wherein the adhesive layer comprises a transition metal.

Description

DESCRIPTION SYSTEMS AND METHODS FOR SPATIO-TEMPORAL ANALYTE MEASUREMENTS OVER A FIELD USING AN OPTICAL WEB CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Serial No. 63/523,690, filed une 28, 2023, and U.S. Provisional Application Serial No. 63/631,904, filed April 9, 2024, the disclosures of each of which are hereby incorporated by reference in their entirety, including all figures, tables, and drawings. GOVERNMENT SUPPORT This invention was made with government support under Grant No. DE-AR0001385 awarded by the Department of Energy. The government has certain rights in the invention. BACKGROUND OF THE INVENTION In agriculture, many greenhouse gases and air pollutants are generated and can have negative impacts on the environment. Thus, limits are placed by government on the amount of emissions that a particular farm or field may produce before reporting requirements go into effect, implementation of mitigation measures, or before claims can be made on environmental sustainability. If the actual generation of a particular emitted gas is minimized or reduced, the lower environment-impact commodity can be sold in a carbon credit market, generating income for the owner of the farm or field coming in under the limit. Such practices can also be monetized in marketing through environmental sustainability claims for their products. It is therefore important to accurately measure greenhouse gas and air pollutant emissions from agricultural practices. BRIEF SUMMARY Embodiments of the subject invention provide novel and advantageous systems and methods for measuring analytes (e.g., greenhouse gases, such as nitrous oxide (N2O)) in the air over a field or other area (e.g., a field in an agricultural setting). An optical web can be cast over the field or other area, using a light source (e.g., a laser) disposed or mounted on a tower or platform overseeing the field or other area, along with meteorological data of wind velocity. With two or more towers disposed around an edge of (e.g., just outside) the field or other area, an estimation of flux emissions and their spatiotemporal parameters can be obtained. Each light source can be configured to provide light at a respective predetermined wavelength (e.g., a midinfrared (mid-IR) wavelength) to one or more reflectors (e.g., retroreflectors) disposed around an edge of (e.g., just outside) the field or other area, providing a path integrated measurement, and then the light returns from the reflector to a detector that is coaligned with each respective light source. “Grid cells” are derived from the overlapping light beams (e.g., laser beams) on the field (or other area) based on the density and/or arrangement of the reflectors. By making many such measurements, a set of linear equations can be generated, which can then be used to solve for the emission in any one grid cell of the field (or other area). This information can be coupled with meteorological data in atmospheric inversion models for the final emission (or analyte concentration) estimation. In an embodiment, a system for measuring at least one analyte in air over a field (e.g., an agricultural field) can comprise: at least two towers disposed at or near a perimeter of the field, wherein each tower of the at least two towers comprises at least one mid-infrared (mid-IR) light source (e.g., laser) disposed thereon and configured to provide light at a predetermined wavelength for a particular analyte, wherein the predetermined wavelength is in a range of from 2 micrometers (pm) to 30 pm; a plurality of reflectors disposed around the perimeter of the field and configured to reflect light from each mid-IR light source of each tower; and an analyzer unit in operable communication with the at least one mid-IR light source of each tower of the at least two towers. Each tower of the at least two towers can further comprise a detector (e.g., a mercury cadmium telluride (MCT) detector and/or an image sensor) disposed thereon and configured to receive signals of light reflected from the plurality of reflectors. The system can further comprise a meteorology station in operable communication with the analyzer unit, and the meteorological station can be configured to obtain meteorological data of the air over the field, air adjacent to the field, or both. The meteorological data can comprise, for example, wind speed, wind direction, air pressure, air temperature, humidity, or a combination thereof. The meteorology station can be disposed within or adjacent to the field. Each analyte of the at least one analyte can be, for example, a greenhouse gas (e.g., N2O, ammonia (NH3), methane (CEE), carbon dioxide (CO2), ozone (O3) or a combination thereof). The system can be configured to measure the at least one analyte with a precision resolving about 1 part in 1000 of the ambient level of each respective gas in the atmosphere away from nearby sources (i.e., background leve