Second generation FLIR common modules

A second generation Forward Looking Infrared (FLIR) kit comprising

• a series of four modules, said modules having housings proportioned to fit within one of three geometric envelopes defined by spaces in Army vehicles that have been allotted to GEN I FLIR systems,
• the first two of said modules each having an optical axis with at least one variable far-infrared optical element along said axis, an optical input at one end of said axis for far-infrared radiation, at least one electrical input transducer coupled to each of said variable optical elements and external electrical inputs for dc and ac signals to energize the electrical transducers therein;
• the first and second of said modules having an optical output for said far-infrared radiation at the end of said axis opposite said one end;
• the third of said modules including an optical axis, an optical input at one end of that axis for far-infrared radiation, and external electrical inputs for dc and ac signals, said third module further including a dewar containing an array of mercury-cadmium-telluride far-infrared detectors with pn junctions, an input for cooling fluid circulated in said dewar and an electronic signal output connected to said detectors;
• the fourth of said modules having inputs and outputs for electronic signals only;
• and
• the respective pairs of said inputs and outputs being serially interconnected.