Characterization of a thermal-infrared field radiometer

A four-band (8.2 - 9.2, 10.5 - 11.5, 11.5 - 12.5, 8 - 14 mu m), prototype, thermal-infrared radiometer with a built-in radiance reference has been fabricated by CIMEL Electronique, Paris, France, for use as a field instrument. This paper briefly describes the instrument and discusses laboratory characterization measurements and results, including spectral response, Linearity of better than 0.8%, field of view of 9.5 degrees, noise-equivalent temperature difference of 0.06 - 0.2 degrees C (depending on the filter) for temperatures of 0 to 75 degrees C, signal-to-noise ratio greater than 1100 for the broad band and greater than 400 for the other bands for temperatures between 10 and 80 degrees C, nonrepeatability of less than 0.35% after four field campaigns (less than 0.2 degrees C in terms of temperature), and absolute calibration.