US Government As Represented by the Secretary of the Army

Kevin C Hung

Jerold R Bottiger

Arthur H Carrieri

Erik S Roese

David J Owens

Pascal I Lim

Jonathan C Schultz

Michael V Talbard

Jack Copper

A system, apparatus, and method of generating Stokes vectors, a Mueller matrix, and polarized scattering from an aerosol aggregate includes providing an incident infrared laser beam; causing the incident infrared laser beam to be polarization-modulated using variable stress/strain birefringence imposed on a ZnSe crystal; defining a Stokes vector associated with the incident infrared laser beam; scattering the incident infrared laser beam from an aggregate aerosol comprising interferents and analyte particles; producing a scattered-beam reactant Stokes vector by causing the scattered incident infrared laser beam to be polarization-modulated; generating a Mueller matrix by taking a transformation of the Stokes vector; and identifying the analyte using the Mueller matrix. The Mueller matrix may comprise M-elements that are functions of a wavelength of the infrared laser beam, backsattering orientation of the infrared laser beam, and a shape and size of the interferents and analyte particles.

Spectrophotopolarimeter sensor and artificial neural network analytics for distant chemical and biological threat detection

An optomechanical switching device, a control system, and a graphical user interface for a photopolarimetric lidar standoff detection that employs differential-absorption Mueller matrix spectroscopy. An output train of alternate continuous-wave COlaser beams [ . . . L:L. . . ] is directed onto a suspect chemical-biological (CB) aerosol plume or the land mass it contaminates (S) vis-&#xe0;-vis the OSD, with L[L] tuned on [detuned off] a resonant molecular absorption moiety of CB analyte. Both incident beams and their backscattered radiances from S are polarization-modulated synchronously so as to produce gated temporal voltage waveforms (scattergrams) recorded on a focus at the receiver end of a sensor (lidar) system. All 16 elements of the Mueller matrix (M) of S are measured via digital or analog filtration of constituent frequency components in these running scattergram data streams (phase-sensitive detection). A collective set of normalized elements {} (ratio to M) susceptible to analyte, probed on-then-off its molecular absorption band, form a unique detection domain that is scrutinized; i.e., any mapping onto this domain by incoming lidar data&#x2014;by means of a trained neural network pattern recognition system for instance&#x2014;cues a standoff detection event.

Photopolarimetric lidar dual-beam switching device and mueller matrix standoff detection system and method

Growing community of inventors

Baltimore, MD, United States of America

Kevin C Hung