Real Time Parallel Channel Spectrometer for 3D Cloud Profiling

OPTRA proposes the development of an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D cloud profiling. The system employs a single modulator and a novel optical configuration which projects an array of angularly dispersed IR beams, each of which exhibits comparable throughput to a single channel OP-FTIR, to an array of respective retroreflector arrays remotely located at the opposite side of the test grid. The return light from each retroreflector array is imaged onto respective detectors that record the spatially-resolved interferograms which are subsequently transformed and analyzed for molecular content via advanced multicomponent algorithms. The result is a capability to sensitively, quantitatively, and simultaneously measure the molecular absorbance and associated concentration-pathlength of an open release plume over an array of spatial regions. Use of two or more I-OP-FTIR sensors around the perimeter of the release allows for tomographic reconstruction of the concentration map of each molecular species contained in the plume. OPTRA has teamed with the University of North Carolina, Department of Public Health, who brings extensive experience in computed tomography for this type of measurement. Phase II activities include the build and test of a prototype sensor and demonstration of the tomographic reconstruction capabilities on a simulant plume