Comparison of near-surface bulk and scintillation C2n measurements during EOPACE

During the Electro-Optical Propagation Assessment in a Coastal Environment (EOPACE) experiment of May-June 1998, IR scintillation measurements were obtained along a 7 km path over San Diego Bay. Simultaneous meteorological measurement were obtained from a buoy located at the midpoint of the transmission path. Bulk estimates of the refractive index structure parameter, Cn2 were computed from the buoy data and compared with scintillation-derived Cn2 values. The bulk Cn2 estimates agreed well with the scintillation measurements in unstable conditions. The agreement between the two methods was poor for near-neutral and stable conditions. In particular, when the air-sea temperature difference has small positive values the bulk model predicts the vertical refractive index gradient approaches zero, resulting in rapid decrease in bulk Cn2 estimates. These predicted decreases in Cn2 were not observed in the path-averaged scintillation measurements.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.