Abstract

The ability to detect and identify effluent gases is a problem that has been pursued with limited success. An algorithm to do this would not only aid in the regulation of pollutants but also in treaty enforcement. Considering these applications, finding a way to remotely investigate a gaseous emission is highly desirable. This research utilizes hyperspectral imagery in the infrared region of the electromagnetic spectrum to evaluate invariant methods of detecting and identifying gases within a scene. The image is evaluated on a pixel-by-pixel basis and is also studied at the subpixel level. A library of target gas spectra is generated using a simple radiance model. This results in a more robust representation of the gas spectra which are representative of real-world observations. This library is the subspace utilized by the detection and identification algorithm. An evaluation was carried out to determine the subset of basis vectors that best span the subspace. Two basis vector selection methods are used to determine the subset of basis vectors; Singular Value Decomposition (SVD) and the Maximum Distance Method (MaxD). The Generalized Likelihood Ratio Test (GLRT) was used to determine whether the pixel is more like the target or the background. The target can be either a single species or a combination of gases, however, this study only looks for one gas at a time. Synthetically generated hyperspectral scenes in the longwave infrared (LWIR) region of the electromagnetic spectrum are used for this research. The test scenarios used in this study represented strong and weak plumes with single or multiple gas releases. In this work, strong and weak plumes refer to the release, which is on the order of tens of grams per second and tenths of grams per second, respectively. This work demonstrates the effectiveness of these invariant algorithms for the gas detection and identification problem.

Library of Congress Subject Headings

Remote sensing--Data processing; Gas detectors; Spectrum analysis; Invariants; Image processing

Publication Date

11-2-2005

Document Type

Thesis

Department, Program, or Center

School of Photographic Arts and Sciences (CIAS)

Advisor

Salvaggio, Carl - Chair

Advisor/Committee Member

Messinger, David

Advisor/Committee Member

Schott, John

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TA1637 .O46 2005

Campus

RIT – Main Campus

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