| 摘要 |
A portable camera system ( 100 ) includes a lens ( 104 ) for forming a focused image of a survey scene ( 106 ) onto a focal plane array ( 108 ). The focal plane array ( 108 ) comprises a cooled two dimensional array of quantum well infrared photo detectors, (QWIP) having a peak spectral responsivity in the wavelength range of 10.4 to 10.8 mum. The camera includes a cooled band pass optical filter ( 110 ) having a peak spectral transmittance approximately centered at a wavelength of 10.57 mum and a full width half maximum spectral transmittance bandwidth of approximately 10.3 to 10.7 mum. The camera system ( 100 ) is usable to detect an invisible gas plume in a video image of a survey scene if the gas plume contains sulfur hexafluoride (SF<SUB>6</SUB>), ammonia, (NH<SUB>3</SUB>), Uranyl Fluoride (U<SUB>2</SUB>O<SUB>2</SUB>F<SUB>2</SUB>), or any other gas having an absorption band that that at least partially falls within the wavelength band 10.3 to 10.8 mum.
|
