Patent ID: 11867618
Assignee: HERIOT-WATT UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 23:
24. A method of extracting, using a non-transitory computer readable medium encoded with a computer program, an effective illumination spectrum Io of a broadband IR light generated by an optical parametric oscillator in order to illuminate chemical targets arranged in an open-path measuring arrangement for the purpose of computing concentrations of each of the chemical targets,
the method comprising the steps of:
storing to the non-transitory computer readable medium spectra I of interference fringes generated by spectrally-modulated broadband IR light upon illumination of the chemical targets,
storing on the non-transitory computer readable medium library absorption spectra for at least one known concentration of each of the chemical targets, and
encoding the medium with a computer program comprising instructions stored therein for causing a computer processor to perform an algorithm which allows the effective illumination spectrum Io to be modelled as a many-point spline function and to become a free parameter when fitting the library absorption spectra for each of the chemical targets to the spectra I of interference fringes generated by spectrally-modulated broadband IR light upon illumination of the chemical targets.