Effect of diurnal variations of rainfall in satellite systems at Ku and Ka Band in Singapore

Hourly rainfall rate data recorded in Singapore over 30 years are processed for analysis. The results obtained from the analysis of diurnal variations of rainfall rate and rain attenuation are presented in this paper. The diurnal cycle of monthly rainfall frequency is presented. From the results, it can be concluded that for the different seasons in Singapore, there are significant variations in diurnal cycles. Afternoon showers are highly frequent throughout the year, especially during the Northeast monsoon season. Early morning rainfall is observed during the pre-monsoons and the Southwest monsoon seasons due to the “Sumatra”. Since earth-space communication systems working in the Ku and Ka bands are severely affected by rainfall, this paper presents the effects of rain attenuation for different seasons in the year for tropical countries such as Singapore. Analysis of the diurnal variation of rain attenuation shows that the hour with the highest rain attenuation in a season might not be the hour with the most frequent rainfall.