PLATO observatory science comes under three categories, see the links to the individual instruments for more details:
The CSTAR and Gattini instruments have taken (and are continuing to take) a large number of wide-field optical images of the sky in various astronomical filters to study transient and variable objects.
PreHEAT, FTS, Snodar, HRCAM, Nigel and the PLATO webcameras are primarily designed to make measurements that will inform a decision on placing future astronomical telescopes at Dome A. PreHEAT and FTS measure the sky opacity in the sub-mm spectral region, Snodar helps us understand the Earth's atmospheric turbulence between 8 and 200 metres above the ice, and HRCAM and the PLATO webcameras will give statistics on cloud cover. In addition, CSTAR, Nigel, and Gattini will provide valuable information on the photometric conditions at Dome A and the sky brightness in a number of wavelength bands.
Snodar produces data on the atmospheric conditions in the boundary layer that is of interest to geophysical scientists. Nigel provides data on aurorae and night sky emission line strengths, and water vapour absorption. HRCAM produces all-sky images of aurora every ~15 minutes throughout the year. PreHEAT and FTS measure the precipitable water vapour in the atmosphere.