METHOD FOR REMOTE SPECTRAL ANALYSIS OF GAS PLUMES

• US 20090257622A1
• Filed: 04/02/2009
• Published: 10/15/2009
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Rafael Advanced Defense Systems Limited (Government of Israel)
• Original Assignee: Rafael Advanced Defense Systems Limited (Government of Israel)
• Inventors: WOLOWELSKY, Karni, Figov, Zvi
• Granted Patent: US 8,284,986 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G01N 21/3518 Devices using gas filter correlation techniques; Devices using gas pressure modulation techniques

Abstract

A method for reducing the effects of background radiation introduced into gaseous plume spectral data obtained by an aerial imaging sensor, includes capturing spectral data of a gaseous plume with its obscured background along a first line of observation and capturing a second image of the previously obscured background along a different line of observation. The parallax shift of the plume enables the visual access needed to capture the radiometric data emanating exclusively from the background. The images are then corresponded on a pixel-by-pixel basis to produce a mapping. An image-processing algorithm is applied to the mapped images to reducing the effects of background radiation and derive information about the content of the plume.

Claims

1. A method for remote sensing of the content of a gas plume based on spectral data, the method comprising the steps of:

(a) deriving a first image taken along a first line of observation of said gas plume with its obscured background,

(b) deriving a second image taken along a second line of observation providing an un-obscured view of said background,

(c) matching said first and said second images to derive a mapping between pixels of said first image and pixels of said second image, and

(d) co-processing spectral data from said correlated images to derive information about the content of the gas plume.

2. The method of claim 1, wherein said line of observation is significantly non-parallel to a length of said gas plume.

3. The method of claim 1, wherein said aerial imaging sensor is operatively coupled with a tracking mechanism to adjust a tilt of said sensor as it advances along said line of travel thereby ensuring a continual image capture of said plume and background.

4. The method of claim 1, wherein said matching said first and second images is implemented by generating a transformed version of one of the images.

5. The method of claim 1, wherein said co-processing spectral data from said matched images is implemented by deriving pixel transmittance values and comparing them to known spectral signatures thereby obtaining a best match.