Current Situation of Radio Frequency Interference (RFI) Profile at Outdoor and Indoor Sites of Faculty of Applied Sciences, UITM, Malaysia

This Radio Frequency Interference (RFI) study is currently one of a main sub-research in radio astronomy in Malaysia. The main objective of this monitoring is to test and qualify the potential of radio astronomical sources that can be observed in Malaysia generally. Analysis process focuses at indoor and outdoor of Faculty of Applied Sciences, UITM Shah ALAM, Malaysia (latitude: 03°06.534’N, longitude: 101°50.396’E). There are three mobile network communications that operate at the upper band frequency of 1800MHz, which are Maxis (1805-1830 MHz), Celcom (1830-1855 MHz) and Digi (1855-1880 MHz) for GSM/LTE network. We observed that both sites having the highest and second highest peak at the same frequency of 420 MHz and 1835 MHz with the same source, which were due to mobile application followed by the lowest peak due to radio navigation satellite. We verified that the source of RFI of 1835 MHz at the Faculty of Applied Sciences may come from Celcom mobile telecommunication network signal because there is transmitter on top of two Celcom towers. This observation must be continuously done to ensure that RFI level does not increase drastically and to ensure that allocation spectrum band that was reserved for radio astronomy activities was always protected.