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 n2, l 0, and L 0. Parallel to the three-aperture data collection was a commercial scintillometer unit which reported C n2 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 n2 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.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.