Effect of antenna size on OTS signal scintillations and their seasonal dependence

Scintillation measurements of the OTS BO beacon signal obtained with an 8.5-m Cassegrain and a 3-m front-fed antenna connected to 20-Hz-bandwidth receivers at the Leeheim experimental station of the Deutsche Bundespost are reported for the period June 1982-March 1983. Signals were recorded for 5 min every 2h, every 72-96 msec, whenever the 3-m output exceeded 0.8 dB peak-to-peak for a 9-sec interval, and on an averaged basis otherwise. Signal variances below 0.003 dB sq and those due to rain are excluded in the statistical evaluation of the results. Monthly cumulative distributions are compiled, and it is shown that the stronger fluctuations occur in the summer months. The equiprobability ratios of the concurrently measured signal variances are calculated, presented in a table, and used to estimate the turbulent-layer altitude. The latter is found to correlate fairly well with ground water-vapor density and grount temperature (monthly averages).