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

US8164742B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Arthur H. Carrieri · Edgewood, US
• Erik S. Roese · Baltimore, US
• David Owens · Boynton Beach, US
• Jonathan Schultz · Guilford, US
• Michael V. Talbard · Rosedale, US
• Pascal Lim · Baltimore, US
• Kevin Hung · Baltimore, US
• Jerold R. Bottiger · Aberdeen, US

Key dates

• Filing date: Jul 18, 2007
• Grant date: Apr 24, 2012
• Expiry date: Feb 21, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S17/88
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

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 CO2 laser beams [ . . . L1:L2 . . . ] is directed onto a suspect chemical-biological (CB) aerosol plume or the land mass it contaminates (S) vis-à-vis the OSD, with L1 [L2] 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 (Mij) 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 {ΔMi,j} (ratio to M11) 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—by means of a trained…