Determination of Radio Environmental Level in Hydrogen (HI) Band Spectrum by using Kurtosis Analysis

Abstract

The Radio Frequency Interference (RFI) nowadays becomes the serious problem and crucial issue in the radio astronomy observation. It absolutely interferes the radio astronomical lines observation in such influencing the data in radio image become worse and take part reduces the signal power level strength. In this study, the analysis has been done to investigate the radio environment level in a wide band (0-9000 MHz) and hydrogen (HI) band (1300-1500MHz) especially. The observation time is 4 hours in one-minute interval at selected sites namely KUSZA Observatory (KO), Langkawi National Observatory (LNO) and East Coast Environmental Research Institute (ESERI). The radio environment level was measured using spectrum analyser at each site.  In analysis part, the kurtosis method is applied and the highest average of kurtosis values indicates the lowest of radio environment level at these sites. From obtained result, the highest average of kurtosis value in wideband obtained at ‘LNO’ which 20.33. While, the highest in average of kurtosis value in specific band was found at ‘KO’ with value of 6.06.  After further analysis and included with kurtosis value, we conclude the best site of low radio environment level in HI band spectrum was found at ‘KO’ and wide band at ‘LNO’. This preliminary study is important to identify the radio environment level in radio astronomical specific band such as HI band.