The Climate in West Peninsular Malaysia: Rain Attenuation Depth during Northeast Monsoon

Abstract

The atmospheric condition is a crucial element during the propagation of a signal from a satellite to the earth. The troposphere layer containing the precipitation is affected more and deteriorates the signal from 20 dB (Ku Band) to 80 dB (Ka-Band). Therefore, the study on rainfall patterns throughout the years is important to get the industry players to dictate the appropriate attenuation margin accordingly because of the current climate change. This paper highlighted the rainfall analysis at the Puncak Niaga, Putrajaya, and Taman Desa Kundang, Rawang, of West Peninsular Malaysia in the year of 2014 to 2018. The lowest rainfall volume was occurred in February, with the accumulation of 386.8 mm in Putrajaya, and 395.2 in Rawang for five consecutive years. The wettest month was in Northeast Monsoon, which was in November. The accumulation of rainfall in Rawang shows the highest amount than in Putrajaya. The highest rain intensities were in November 2014, which amounted to 145 mm/h, and the average five years rain intensities at Rawang amounted to 84 mm/h for 0.01% of outage time were used as input to ITU-R P.618-13 rain attenuation prediction model. The result suggested different values, wherein 46.19 dB and 33.88 dB respectively. Therefore, a trade-off between quality of signal could be concluded in this experiment wherein the month of Northeast Monsoon would experience more outage time if the averaged five years rain intensity-induced attenuation margin would be used. A trade-off between user satisfaction and operational cost will be left to the satellite operators to consider.