Abstract: A spectral imaging system configured to obtain spectral measurements in a plurality of spectral regions is described herein. The spectral imaging system comprises at least one optical detecting unit having a spectral response corresponding to a plurality of absorption peaks of a target chemical species. In an embodiment, the optical detecting unit may comprise an optical detector array, and one or more optical filters configured to selectively pass light in a spectral range, wherein a convolution of the responsivity of the optical detector array and the transmission spectrum of the one or more optical filters has a first peak in mid-wave infrared spectral region between 3-4 microns corresponding to a first absorption peak of methane and a second peak in a long-wave infrared spectral region between 6-8 microns corresponding to a second absorption peak of methane.

Abstract: A laminated transparent digitizer sensor assembly comprises a first transparent layer patterned on one surface with a first array of conductors and an array of conductive elements electrically isolated from the first array of conductors; and a second transparent layer patterned on one surface with a second array of conductors; wherein the first and second layers are laminated with non-conducting transparent laminating material, such that the patterned surfaces face each others and wherein conductive material is provided between the conductive elements and conductors of the second array of conductors.