Laboratory exercise for the radiometry student

Abstract

The U.S. Air and Space Forces require optical expertise among their personnel. The Air Force Institute of Technology offers a graduate optics curriculum, which includes a three-course sequence to educate students in the optical concepts of radiometry and radiometric instrumentation. We find radiometry is often a deceptively difficult concept for students to master. To address this, we have developed an experiment in our optics-laboratory coursework to help them gain this mastery. A Fourier-transform infrared spectrometer (FTS) is used to collect spectral data from an unknown sample. FTS calibration and data collection are discussed here, as are the two specific samples used, one with specular reflectance properties, the other with diffuse. The analysis methodology used on the data is also discussed. This is a good radiometry exercise to reveal to the student what can be learned about an unknown material’s optical properties in a remote-sensing scenario and is the basis upon which the limiting simplifications of this initial experiment may be generalized to address more difficult, but more realistic, remote-sensing analyses.