Analysis of low elevation slant path scintillation

The analysis of a scintillation database recorded at British Telecom's Goonhilly Satellite Earth Station between February 1988 and August 1990 is described. The signal frequency is 11.198 GHz and the slant path elevation angle is 3.3 degrees . The objective of this analysis is to determine if the CCIR 1990 scintillation model is applicable at a 3.3 degrees elevation angle. The database is pre-processed to yield clear sky (or dry) and degraded sky (or wet) subsets. Algorithms to calculate the predicted and measured scintillation standard deviations and CDF (cumulative distribution function) of fades are developed. The CCIR scintillation model is found to overpredict the average-year monthly standard deviation of the clear sky data. A new reference standard deviation is then derived using the clear sky data. The modified model fits the clear sky data well, but underpredicts the degraded sky scintillation. When data contaminated by multipath propagation is removed only a small improvement in the agreement between measured and predicted standard deviation is observed.<
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