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5. CONCLUSIONSA method to determine the refractive index structure constant, Cn2, from highresolution radiosonde data has been developed. A full validation of this method was not possible to carry out due to the lack of other datasets, e.g. radar measurements. However, the results obtained present the values and behaviour similar and within the range of those observed by other authors. The statistical behaviour of Cn2 also shows the expected lognormality further confirming the general correctness of the approach. The distributions of turbulent layer thickness are as well within the range of those observed for the outer scale turbulence providing further reassurance on the taken approach. Statistical results were obtained for 4 sites at different latitudes as well as an exponential fit to the median for applications where simplified models for Cn2 suffice. These statistical results show the expected physical impact of the boundary layer, orographic features and local climate. 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Table 1: Technical specifications of the Vaisala RS80 radiosonde. Table 2: Radiosonde stations Figure 1: Block diagram of methodology Figure 2: C_{n}^{2} for a single radiosonde launch (Camborne 1^{st} January 2002 at 0600 UTC). Data points at 10^{21} represent stable layers while scattered data points show C_{n}^{2} for turbulent layers Figure 3: Histogram of C_{n}^{2} at a height of 6000 meters. Data covers 4 years (19941996, 2002) of 4 daily radiosonde launches in Camborne. Figure 4: Mean of log C_{n}^{2} and 10, 50 and 90 percentiles as a function of height derived from the cumulative distribution of C_{n}^{2} for Camborne (data comprising 4 years of 4 daily launches). Figure 5: The probability of turbulence as a function of height for Camborne (data for 4 years of 4 daily launches). Figure 6: Percentiles derived from the probability distribution of C_{n}^{2} conditioned to having turbulence at Camborne (data for 4 years of 4 daily launches). Figure 7: Percentiles as a function of height for the thickness of the turbulent layer. The percentiles refer only to turbulent samples. Figure 8: Mean of log C_{n}^{2} and 10, 50 and 90 percentiles as a function of height derived from the cumulative distribution of C_{n}^{2} for Lerwick. Figure 9: Mean of log C_{n}^{2} and 10, 50 and 90 percentiles as a function of height derived from the cumulative distribution of C_{n}^{2} for Gibraltar. Figure 10: Mean of log C_{n}^{2} and 10, 50 and 90 percentiles as a function of height derived from the cumulative distribution of C_{n}^{2} for St. Helena.
