Ozone is the most important minor constituent of the upper atmosphere. It plays a very important role in the chemistry and photochemistry of the stratosphere. For this reason, a large number of studies have been performed on this molecule. In particular, pure rotational and vibrational-rotational spectra have been recorded with several techniques (1).
P. De Natale,
"Tunable far infrared spectroscopy of 16O3 ozone", Proc. SPIE 1576, 16th International Conference on Infrared and Millimeter Waves, 15760J (1 October 1991); doi: 10.1117/12.2297732; https://doi.org/10.1117/12.2297732