Measuring Optical Turbulence Parameters With a Three-Aperture Receiver

摘要

Intensity fluctuations from a 532nm CW laser source were collected over an outdoor 1km path, 2m above the ground, with three different receiving apertures. The scintillation index was found for each receiving aperture and recently developed theory for all regimes of optical turbulence was used to infer three atmospheric parameters, C_n~2, l_0, and L_0. Parallel to the three-aperture data collection was a commercial scintillometer unit which reported C_n~2 and crosswind speed. There was also a weather station positioned at the receiver side which provided point measurements for temperature and wind speed. The C_n~2 measurement obtained from the commercial scintillometer was used to infer l_0, L_0, and the scintillation index. Those values were then compared to the inferred atmospheric parameters from the experimental data. Finally, the optimal aperture sizes for data collection with the three-aperture receiver were determined.