Microbolometer Spectrometer: Applications and Technology

Current Thermal Infra Red (7.14 µm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. Now due to the increased performance of uncooled microbolometer arrays, the next generation of instruments can be designed without cryogenic cooling. TNO TPD has designed a spectrometer called the Micro Bolometer Spectrometer (MIBS), that is able to provide co-registered images in the 7 to 14 µm wavelength region with an acceptable NETD performance on the basis of currently available detectors. Apart from space based multispectral imaging, the concept can also be used for several other applications, for example, CO2 monitoring through the broader spectral response. The removal of the standard highpass filter of the bolometer detector allows imaging in both the 3 to 5 and 7 to 14 µm atmospheric windows at the same time in a co-registered fashion. Applications include forest fire detection, military reconnaissance and, wideband flame analysis (NOx detection in industrial ovens).