Measurements of tropospheric scintillation on millimetre-wave satellite link

Abstract

Tropospheric scintillation statistics in the millimetre-wave band have been obtained in Madrid, using the ITALSAT satellite beacon at 50 GHz. Few studies have been conducted previously at this band. The UCL radiosonde-based method predicts fairly well the mean variance and the distribution of amplitude in the summer months, when scintillations are stronger. The ITU-R prediction model, based on surface meteorological parameters, performs worse.

Tropospheric Scintillation With Concurrent Rain Attenuation at 50 GHz in Madrid

“…The increment of intensity is not quite significant for attenuations up to 2-3 dB, as part of the measured scintillation is actually due to turbulence inside the clouds, with no precipitation. In fact, the mean intensity value in the 1-2-dB interval, 0.145 dB, is very close to the mean value of dry scintillation, 0.139 dB [10]. The change of slope around 10-12 dB may indicate the increasing effect of system noise on the measurements.…”

“…The experiment consisted in measuring the 50-GHz beacon of the ITALSAT satellite for one year [9]. The main results concerning dry scintillation were published in [10].…”

Comparison of the refractive index structure constant prediction using radiosonde data to in-situ thermosonde measurements

“…Atmospheric turbulence can significantly affect the received field amplitude by degrading the signal-to-noise ratio. On the other hand, measurement of the refractive-index fluctuation intensity can provide information on the local state of the atmosphere itself, which is of great interests to atmospheric physics research [1][2][3][4][5][6][12][13][14][15][16]. Atmospheric scintillation is caused by small-scale fluctuations of the refractive index due to the turbulence.…”

“…Scintillation yields random fades and enhancements of the received signal, which could impair the availability of low-margin systems particularly at low-elevation angles, interfering with tracking systems and fade mitigation techniques. Scintillation has to be considered in the design and planning of satellite communications systems at frequencies above 10 GHz [13][14][15].…”