This paper discusses a program for remote sensing of air pollutants called "Multispectral Observation of Pollutants System (MOPS)." The broad objective of the program is to photograph "invisible" gaseous pollutants by combining ultraviolet imaging in several spectral bands with portable data processing equipment. Electronic cameras using solid state imaging arrays of large dynamic range will permit very low contrast images to be electronically ratioed and contrast enhanced, thus bringing out pollutant images which are below the contrast threshold of film. Such photographs will allow synoptic coverage of geographic areas providing source, sink, and flow data on pollutants, and will provide reconnaissance and pointing information for other remote sensors. The principle gases to be mapped by MOPS will be ozone (03), sulfur dioxide (SO2) ) and nitrogen dioxide (NO2).
"Imaging Air Pollutants In The Near Ultraviolet", Proc. SPIE 0091, Methods for Atmospheric Radiometry, (27 December 1976); doi: 10.1117/12.955080; https://doi.org/10.1117/12.955080