Hyperspectral Chemometric Algorithms for Remote Detection of Hazardous Gases

Opto-Knowledge Systems, Inc., (OKSI), of Manhattan Beach, CA, was awarded a Phase I SBIR contract by the Air Force Armstrong Laboratory. The program, titled "Hyperspectral Analysis Techniques for Remote Sensing Imaging Spectroscopy," focuses on the development of chemometric algorithms for the remote detection of hazardous air pollutants, chemical warfare agents, and illicit drug manufacturing by-products. The algorithms are developed to analyze hyperspectral signatures acquired by the Thermal Infrared Imaging Spectrometer (TIRIS). OKSI is currently testing a prototype version of the TIRIS which operates in the 7.5 to 14.0 µm spectral range, has 64 spectral, and 20 spatial bands. The TIRIS, an airborne sensor operating in a pushbroom mode, was assembled by OKSI under an ARPA contract in collaboration with NASA/JPL.

Under the Air Force program, OKSI is developing two computer models. One solves the "forward" problem, i.e., predicting the sensor signal under specified environmental parameters. The second, addresses the "inverse" problem, under which the unknown compounds are identified, given the sensor's measurements. A "smeared line" model is used in the algorithms to model spectral signature of compounds of interest. Spectra of compounds included in the model's database were obtained from the EPA's spectral library of Hazardous Air Pollutants (HAPs), and were de-resolved to match the spectral resolution of TIRIS. The model uses the NPIC library for terrain background spectra.

Acquired by an airborne imaging spectrometer, and using GPS, the TIRIS spectral imagery can be directly tied to Geographical Information Systems (GIS), for accurate geolocation. This may be extremely important for emergency response, plume tracking, and battle field management.

Some of the activities mentioned here can be found in the "Hyperspectrum" newsletter, published by OKSI.

Nahum Gat, Ph.D., President
Opto-Knowledge Systems, Inc. (OKSI)
19805 Hamilton Avenue

Torrance, CA 90502
Phone: 310/756-0520, Fax 310/756-0511

To send mail: info @ oksi.com