METHOD AND DEVICE FOR QUANTIFICATION OF GASES IN PLUMES BY REMOTE SENSING

• US 20130100451A1
• Filed: 11/29/2012
• Published: 04/25/2013
• Est. Priority Date: 06/29/2009
• Status: Active Grant

• Current Assignee: Hager Environmental and Atmospheric Technologies, LLC
• Original Assignee: Hager Environmental and Atmospheric Technologies, LLC
• Inventors: Hager, J. Stewart, Yerem, Geoffrey
• Granted Patent: US 8,654,335 B2
• Time in Patent Office: Days
• US Class Current: 356/438
• CPC Class Codes: G01N 2021/1793 Remote sensing
• CPC Class Codes: G01N 2021/1795 Atmospheric mapping of gases
• CPC Class Codes: G01N 2021/399 Diode laser
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/532 with measurement of scattering and transmission

Abstract

Method and device for quantifying ingredients of a plume. In one embodiment, the method includes sweepingly directing a beam of light through the plume to a surface on which the beam of light is scattered, acquiring the scattered light scattered from the surface, and processing the acquired scattered light to determine an amount of ingredients of the plume. In one embodiment, the height of the back of the vehicle is measured as the top of the plume for calculating the total mass-per-distance of the plume. In another embodiment, by comparing the absorption spectrum of the plume and the background absorption spectrum of which no plume exists, the non-methane hydrocarbons (NMHC) of the plume emitted from a vehicle can be quantified.

Claims

1. A method for quantifying ingredients of a plume, comprising the steps of:

(a) sweepingly directing a beam of light through the plume to a surface on which the beam of light is scattered;

(b) acquiring the scattered light scattered from the surface; and

(c) processing the acquired scattered light to determine an amount of ingredients of the plume.

2. The method of claim 1, wherein the processing step comprises the step of calculating an effective width, w_i, of each sweeping light beam, wherein the effective width w_i satisfies with the relationship of:

3. The method of claim 2, wherein the thickness/of the plume is corresponding to a height of the rear of the vehicle that emits the plume.

4. The method of claim 3, wherein the total mass-per-distance of the plume satisfies with the relationship of:

5. The method of claim 1, wherein the directing step is performed with a Galvanometer.

6. The method of claim 1, wherein the acquired scattered light is processed in terms of an absorption spectrum of the plume.

7. The method of claim 6, further comprising the step of obtaining a background absorption spectrum of which no plume exists.

8. The method of claim 7, further comprising the step of comparing the absorption spectrum of the plume and the background absorption spectrum so as to quantify non-methane hydrocarbons (NMHC) of a plume.

9. A device for quantifying ingredients of a plume, comprising:

(a) a light source for emitting a beam of light through the plume to a surface on which the light is scattered;

(b) a detector for acquiring the scattered light scattered from the surface; and

(c) a processor for processing the acquired scattered light to determine an amount of ingredients of the plume.

10. The device of claim 9, wherein the processor is configured to perform the function of calculating an effective width, w_i, of each sweeping light beam, wherein the effective width w_i satisfies with the relationship of:

11. The device of claim 10, wherein the thickness/of the plume is corresponding to a height of the rear of the vehicle that emits the plume.

12. The device of claim 11, wherein the total mass-per-distance of the plume satisfies with the relationship of:

13. The device of claim 9, wherein the processor is configured to perform the function of obtaining an absorption spectrum of the plume.

14. The device of claim 13, wherein the processor is configured to perform the function of comparing the absorption spectrum of the plume and a background absorption spectrum of which no plume exists, so as to quantify non-methane hydrocarbons (NMHC) of a plume.

15. The device of claim 9, further comprising a positioning optics for sweepingly directing the beam of light through the plume to the surface on which the beam of light is scattered.

16. The device of claim 15, wherein the positioning optics comprises a Galvanometer.

17. The device of claim 9, wherein the light source comprises one or more coherent light sources.

18. The device of claim 17, wherein the light source comprises a tunable laser.