Downloaded 25 Jun 2012 to 203.82.87.143. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions

Z.S.Hamidi
1, 2*
, Z. Z. Abidin
2
, Z. A. Ibrahim
2
, N.N.M. Shariff
2
1
Faculty of Applied Sciences, University Teknologi MARA, UiTM S.Alam Selangor, Malaysia
2
Faculty of Science, University Malaya, Kuala Lumpur, Malaysia zetysh@salam.uitm.edu.my
Abstract.
Apart of monitoring the Sun project, the Radio Frequency Interference (RFI) surveying in the region of (1-
1200) MHz has been conducted. The main objective of this surveying is to test and qualify the potential of monitoring a continuous radio emission of Solar in Malaysia. This work is also an initiative of International Space Weather Initiative
(ISWI) project where Malaysia is one of the country that participate a e-Callisto Spectrometer network in order to study the behavior of Solar radio burst in frequency of ( 45-800) MHz region which will be install in this October. Detail results will indicate the potential of monitoring a solar in Malaysia.
Keywords: Radio Frequency Interference (RFI), radio astronomy, RFI sources
Sun, the potential and multi- frequency sources that address a variety focus: a study of short and long term magnetic evolution, the theoretical study of mechanisms of energy transfer and physical characteristics, the behavior of the corona, chromospheres and photosphere and the light scattering of the solar itself [1]. Observation of the
Sun in radio wavelength gives a lot of advantages in some aspects. It is also a very good indicator to discover new phenomena that might drastically happen especially in solar maximum cycle. In
Malaysia, the monitoring of solar in this region has just in the beginning phase. Yet, it is a good started by collaborate internationally with the International
Space of Weather Initiative Program (ISWI). In this committee, we are hosting the e-Callisto network.
There are a few countries that participate in this networking research. The main objective is to study the characteristics solar burst within this period, in the maximum cycle. As we know, monitoring of the
Sun in this phase before going to maximum peak is very important because in this period, it will showed the actual impact that caused the Sun behavior in the mid of 2012, where we are expecting the maximum cycle could be happen. A part from that, we also noticed that Sun is now in 23 rd
cycle with the longest period of cycle, almost 13 years. This is serious concern because within this period, it also showed the very minimum activities where some of the physicists worried and believed that the potential of the Sun to generate up to the very maximum activities in 2012 is very high. Therefore, it is a strong reason why do we need to study and monitor the Sun. However, before we want to monitor the
Sun, it is good to survey the radio frequency interference (RFI) should be done so that we will know the quality signal of the Sun.
As we know, one of the challenges of the next generation radio telescope for astronomy is its capacity to cope with increasing polluted of RFI [3].
For that, it is very important to identify and continuously monitor the unwanted signals which are emitted due to the massive global increase in technology application. We also are comparing the same region at different sites in Malaysia in other to determine strategic sites for solar radio astronomical purpose.
RFI profiles at frequencies from 1MHz till 1200
MHz were covered at of the following different sites:
(a) Two sites of Universiti Teknologi MARA
(3°5 ′ 00 ″ N 101°32 ′ 00 ″ E/ 3.0833333°N
101.5333333°E), indicate that the areas enhanced a minimum RFI strength. Based on the RFI profiles investigations that have been conducted by Zamri
Zainal Abidin et.al, the best sites with weak signal of
RFI is at Langkawi observatory [4]. These are followed by INSTUN, Jelebu which is the most low
International Conference on Physics and its Applications
AIP Conf. Proc. 1454, 43-46 (2012); doi: 10.1063/1.4730684
© 2012 American Institute of Physics 978-0-7354-1055-8/$30.00
43
Downloaded 25 Jun 2012 to 203.82.87.143. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions

humidity sites in Malaysia and University of Malaya.
As a part of continuity surveying the best sites, we selected another sites in last year. We extend the surveying by monitoring RFI at two areas: Faculty of
Applied Sciences and Parade Square for indoor and outdoor purpose respectively. These sites are located about 25 kilometers west of the Kuala Lumpur and the most nearest place to the National Space Agency,
Banting, Selangor, the site where we plan to setup the e-Callisto system.
Malaysia Space Centre, Banting Selangor, 400 acre land is been chosen for e-Callisto project seems there has a complete facilities that relevant enough to build up the radio astronomical sites. These are also far away from city and one of the main sites instead of Langkawi Observatory itself. It is about 25 minutes from UiTM, Shah Alam. Based on this factor, it is hope that it will be the best indicator that represents the Malaysia Space Centre as well.
The results are then will be compared with the reference of frequency allocation of International
Telecommunication (ITU) and Malaysian
Communication and Multimedia Commission
(MCMC) as well.
The measuring system is containing the copper antenna, 1.4 GHz and 2.8 GHz spectrum analyzer with 180 kHz resolution bandwidth. The RFI survey has been done in day starting from 9.00am till 17.00 pm on 21 st
and 22 nd
of August 2010. We then identify the continuity signal of frequency responses from the analyzer. The data will be transferred to computer for further analysis. Figure 1 show the RFI system connection. Detailed analysis also revealed the interference sources that caused interruption of solar signal.
FIGURE 1.
RFI system connection.
In order to carefully analyze the specific regions, we need to divide into 3 region i) 1-400 MHz (ii)
400-800 MHz and (iii) 800-1200 MHz as quantifiable boundary. We consider each potential sources of RFI with the signal more than -100.3 dBm for Faculty of Applied Sciences and Square Parade.
It is obviously showed that Padang Square is indicating the lowest RFI with average of -
100.30dBm compare Faculty of Applied Sciences, -
100.007dBm. Detailed analysis also found that 50 and 17 individual sources contribute as an interferer and mostly are telecommunication and radio navigation applications for both sites respectively.
According to the results, the unwanted signal is obviously observed from 800-1200 MHz region.
Most of this source is from the mobile telecommunication which dominant in this region.
This can be proving in Applied Sciences site (800-
1200MHz) as high as ~ 80 dBm. We also found that this site is a moderate site comparing Sekayu and
Jelebu sites.
44
Downloaded 25 Jun 2012 to 203.82.87.143. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions

T RFI Profiles at different sites
RFI Strength (dBm)
Langkawi -100.330
Parade Square (Ui iTM) -100.300
Applied Sciences Faculty -100.007
(UiTM)
Sekayu
Jelebu
-99.900
-92.10 i) 1MHz – 400MHz ( a) Applied Sciences (b) Square Parade
FIGURE 2 .
The comparison of Square.
45
Downloaded 25 Jun 2012 to 203.82.87.143. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions

Solar radio astronomy observation potentially be made specifically for this purpose: 1) solar wind
(73.00-74.60 MHz), solar burst (45-800 MHz), continuum solar radio emission (1-800 MHz) [6].
Those are the potential observation that can be monitor in radio region. Technically, Malaysia Space Centre should be less of RFI signal compare with UiTM based on the site where far away from urban.
However, in the band 800-1200MHz and 1600-
2000MHz, every practicable effort will be made to avoid the assignment of frequencies to stations in the fixed and mobile services that could interfere with radio astronomy. We can say that there is no a high unwanted signal from 1-800 MHz. This is a good indicator for solar burst monitoring purpose as well as the other astronomical object, generally.
We strongly believed that our country can potentially develop the radio astronomical research especially in solar monitoring based on the positive sign in RFI levels and the suitable weather condition.
Now is the best time for new opportunities in solar and climate research. between University Malaya and UiTM. This research has made use of Radio Astrophysics and Cosmology
Lab Facility. This project is an initiative of the
International of Space Weather Initiative (ISWI) program.
1. C. Fröhlich and J. Lean, Geophysical Research letters
25 , 4377-4380 (1998).
2. S. Misra and Christopher S. Ruf, “Comparison of pulsed sinusoid RFI detection algorithms using time and frequency subsampling”, 2008.
Communications 8 , 279-289 (2009).
4. Z. Z. Abidin, et al , NewA 14 , 579–583 (2009).
5. J. Fielding, “Amateur Radio Astronomy”, Radio Society of Great Britain, pp. 283–284, 2006.
6. MCMC manual of ‘Spectrum Plan, Malaysian
Communication and Multimedia Commission’ 2006.
Malaysia is one of the strategic countries to monitor the Sun based on the condition of the weather, and the duration of a day, almost 12 hours per day.
However, it is suggested that the antenna that will be constructed for e-Callisto system should have a higher gain and sensitivity in order to get a good data and eliminate unwanted signal of RFI. It should be noted that the cable that connected from the antenna to the spectrometer should be less than 5 meter. Our next planning in this year is to test and qualify the RFI level in Malaysia Space Centre, Sg Lang Banting, Selangor.
It is hope that the survey will continue from time to time in a consistent mode so that any polluted signal for radio astronomy purpose can be protected. It is hope that we can contribute the good data for solar burst monitoring towards the maximum cycle beginning the end of this year.
This work was partially supported by the
Excellence Fund UiTM and PPP UM P346/2010B grants. We thank the anonymous referee for helpful comments which greatly improved and clarified this work. RFI monitoring is a project of cooperation
46
Downloaded 25 Jun 2012 to 203.82.87.143. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions