A Comparison between Line-Averaged Observation of Cn2 from Scintillation of a CO2 Laser Beam and Time-Averaged in situ Observations

Abstract

The refractive-index structure parameter Cn2 was measured from scintillation of a CO2 laser beam over a 5.9 km path at 40 m height and compared to in situ observations of Cn2 at the optical receiver location. A reasonable agreement is found, but 10 min averaged in situ Cn2 data have larger variability than optical Cn2 data due to scattered clouds and limited averaging time of the in situ measurements. The likely role of convective plumes in the difference in variability is discussed.