I remember people from Sandia National Labs using LIDAR to monitor pollution around Albuquerque circa 1990. Turns out this been a thing for a long time:
I think in those cases you know what the pollutant is that is in a gas that you know what it is and want to make a quantitative determination whereas the system described in that paper is supposed to make sense of some random gas.
Sandia and other labs have indeed been working on this type of MASINT collection for a long while. Their primary use case is remote characterization of effluents to determine if a given facility is being clandestinely used for things like chemical weapons production or nuclear materials enrichment.
https://ntrs.nasa.gov/citations/19720026861
and is still going on
https://iopscience.iop.org/article/10.1088/1748-9326/ab9cfd
https://idstch.com/security/lidar-technology-revolutionizing...
I think in those cases you know what the pollutant is that is in a gas that you know what it is and want to make a quantitative determination whereas the system described in that paper is supposed to make sense of some random gas.