Rapid remote sensing by spectrum matching technique: 2. Application in the laboratory and in lunar observations

A spectrum matching technique has been developed for rapid remote compositional sensing. The method is based on the instrumental comparison, over a selected wavelength interval, of the mid-infrared emission spectrum from the target with the reflection spectra of a series of polished plates of known composition, which are included as an integral part of the instrument. It is primarily useful when the remote sensing is carried out on a low energy target in the presence of a time variable intervening attenuator. To acquire meaningful data under these conditions, a premium is placed on rapidity of measurement. Part 1 of this paper dealt with a description and discussion of the method [Hunt, 1966]. The feasibility of the technique is demonstrated in the laboratory using two instruments—one a simple single spot measuring device and the older a more sophisticated x-y scanning instrument. The 8 to 14 micron daytime lunar emission was examined using the simpler of these two instruments, and small but consistent differences in emission have been delineated between different areas on the lunar surface, which indicate that either compositional and/or particle size differences exist.