Polarimeter with multiple independent tunable channels and method for material and object classification and recognition

A sensor for classifying or recognizing a target within a field-of-view using multiple independent channels comprising:

• a source of controlled electromagnetic radiation positioned in a path with a detector and the field-of-view positioned there between;
• a first scanning element positioned to direct a beam from the source of controlled electromagnetic radiation serially among a first set of independent modulators located on a set of independent arms;
• the first set of independent modulators, wherein each member of the first set of independent modulators defines an independent channel, configured to modulate a state of the beam among a set of independent states;
• a second scanning element;
• an assembly of reflectors located on each independent arm configured to redirect the beam on each independent arm to the second scanning element that redirects the beam from each independent arm to a common path that is pointed at the field-of-view;
• an electromagnetic-radiation receiver positioned to direct electromagnetic radiation reflected from or transmitted by objects within the field-of-view to a second modulator independent of the first set of independent modulators;
• the detector, positioned to receive the electromagnetic radiation from the second modulator, wherein the detector produces a set of signals that are synchronized with the channels formed by the first set of independent modulators and the second modulator;
• and
• a processor connected with a memory, wherein the processor is configured to execute a classification algorithm stored in the memory by applying a user-adjustable threshold to the set of detector signals to assign a class label to the set of detector signals, wherein the classification algorithm specifies a function of the threshold in terms of the set of channels formed by the first set of independent modulators and the second modulator wherein the first scanning element is a scanner mirror attached to a first mechanical scanner that comprises a rotation axis and wherein the assembly of reflectors is an assembly of mirrors and wherein the scanner mirror is a flat mirror parallel to the rotation axis and the second scanning element is a wedge mirror mounted on the first mechanical scanner at an angle to the flat mirror.

A polarimeter for classifying or recognizing a target within a field-of-view using multiple independent polarization channels comprising:

• a source of controlled electromagnetic radiation positioned in a path with a detector and the field-of-view positioned there between;
• a first scanning element positioned to direct a beam from the source of controlled electromagnetic radiation serially among a first set of independent polarization modulators located on a set of independent arms;
• the first set of independent polarization modulators, wherein each member of the first set of independent polarization modulators defines an independent polarization channel, configured to modulate a polarization state of the beam among a set of independent polarization states;
• a second scanning element;
• an assembly of reflectors located on each independent arm configured to redirect the beam on each independent arm to the second scanning element that redirects the beam from each independent arm to a common path that is pointed at the field-of-view;
• an electromagnetic-radiation receiver positioned to direct electromagnetic radiation reflected from or transmitted by objects within the field-of-view to a second polarization modulator independent of the first set of polarization modulators;
• the detector, positioned to receive the electromagnetic radiation from the second polarization modulator, wherein the detector produces a set of signals that are synchronized with the channels formed by the first set of polarization modulators and the second polarization modulator;
• and
• a processor connected with a memory, wherein the processor is configured to execute a classification algorithm stored in the memory by applying a user-adjustable threshold to the set of detector signals to assign a class label to the set of detector signals, wherein the classification algorithm specifies a function of the threshold in terms of the set of channels formed by the first set of polarization modulators and the second polarization modulator.