  A six-night optical turbulence monitoring campaign has been carried at Cerro
Paranal observatory in February and March, 2023 to facilitate the development
and characterisation of two novel atmospheric site monitoring instruments - the
ring-image next generation scintillation sensor (RINGSS) and 24-hour Shack
Hartmann image motion monitor (24hSHIMM) in the context of providing optical
turbulence monitoring support for upcoming 20-40m telescopes. Alongside these
two instruments, the well-characterised Stereo-SCIDAR and 2016-MASS-DIMM were
operated throughout the campaign to provide data for comparison. All
instruments obtain estimates of optical turbulence profiles through statistical
analysis of intensity and wavefront angle-of-arrival fluctuations from
observations of stars. Contemporaneous measurements of the integrated
turbulence parameters are compared and the ratios, bias, unbiased root mean
square error and correlation of results from each instrument assessed. Strong
agreement was observed in measurements of seeing, free atmosphere seeing and
coherence time. Less correlation is seen for isoplanatic angle, although the
median values agree well. Median turbulence parameters are further compared
against long-term monitoring data from Paranal instruments. Profiles from the
three small-telescope instruments are compared with the 100-layer profile from
the stereo-SCIDAR. It is found that the RINGSS and SHIMM offer improved
accuracy in characterisation of the vertical optical turbulence profile over
the MASS-DIMM. Finally, the first results of continuous optical turbulence
monitoring at Paranal are presented which show a strong diurnal variation and
predictable trend in the seeing. A value of 2.65" is found for the median
daytime seeing.
