Zety Sharizat Hamidi

Indication of Radio Frequency Interference (RFI) sources for solar burst monitoring in Malaysia

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.

Designing and Constructing Log Periodic Dipole Antenna to Monitor Solar Radio Burst: e-Callisto Space Weather

A Log Periodic Dipole Antenna (LPDA) for solar burst monitor in the range of (45 -870) MHz applications is presented. In this paper, we make an effort in designing a portable LPDA that suitable with the criteria, specification and practical enough although is the boom length size of the antenna is 5.45 meter. We choose value of 0.14 spacing factor τ= 0.8 as a directivity of antenna. This LPDA is constructed by using two (2) rod aluminums type with nineteenth (19) elements of different sizes. Some of suggestions on improving this design are also presented.

Radio frequency interference affecting type III solar burst observations

The solar burst extinguish from the Sun’s corona atmosphere and it dynamical structure of the magnetic field in radio wavelength are studied. Observation of solar radio burst with Compact Astronomical Low cost Low frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) from ETH, Zurich in frequency range of 45 until 870 MHz. Observation done at Pusat Angkasa Negara, Banting, Selangor and successfully detected the solar burst type III on 9th March 2012 from 4:22:00 UT until 4:28:00 UT. The solar burst emission is associated with M6.3 solar flare which occurred at sunspot AR1429 at 03:58UT were observed by NOAA. Frequency ranges chosen as the best ranges for solar monitoring in Malaysia is 150 MHz until 400 MHz. The highest signal amplitude within this frequency ranges is 1.7619 dB at 153.188 MHz (Government Use) have potential to influence the detection of solar radio burst type III within 20 until 400 MHz.

Observations of coronal mass ejections (CMEs) at low frequency radio region on 15th April 2012

We have carried out a case study on Coronal Mass Ejections (CMEs) as a massive burst of solar wind and magnetic fields rising above the solar corona. During 15th April 2012, solar filament eruption was accompanied by intense CMEs. This explosion of CMEs observed by the Solar Dynamics Observatory with sunspot AR1458 is crackling with C–class solar flares. Solar flare type B3 and C2 were observed beginning 2241 UT and 0142 UT in the active region AR1458. In the present work, we focus in the range of the low frequency region from 150 MHz to 400 MHz. At preliminary stage, starting from 12.00 UT till 1.00 UT there is a strong signal which indicates a formation of burst. Type II burst originated from solar corona can be observed in the range of 150 MHz to 230 MHz. Instead of type II, a moving type IV and continuum type III burst can be detected at 150 MHz and lasting for 1 hours. This event is considered as second largest CMEs been detected since five (5) years. We can then conclude that currently, the Sun is i...

Dynamical structure of solar radio burst type III as evidence of energy of solar flares

Observations of low frequency solar type III radio bursts associated with the ejection of plasma oscillations localized disturbance is due to excitation atoms in the plasma frequency incoherent radiations play a dominant role at the meter and decimeter wavelengths. Here, we report the results of the dynamical structure of solar flare type III that occurred on 9th March 2012 at National Space Centre, Sg Lang, Selangor, Malaysia by using the CALLISTO system. These bursts are associated with solar flare type M6 which suddenly ejected in the active region AR 1429 starting at 03:32 UT and ending at 05:00 UT with the peak at 04:12 UT. The observation showed an initial strong burst occurred due to strong signal at the beginning of the phase. We also found that both solar burst and flares tend to be a numerous on the same day and probability of chance coincidence is high. It is clearly seen that an impulsive lace burst was detected at 4:24 UT and it is more plausible that the energies are confined to the top of t...

Evaluation of signal to noise ratio (SNR) of log periodic dipole antenna (LPDA)

Logarithmic periodic dipole antenna (LPDA) was constructed for monitoring Sun in the range of (45 -870) MHz to precisely match the solar monitoring requirements. In our work, we choose rod aluminiums type as a conductor with nineteenth (19) elements of different sizes. Beside established construction techniques, several test setups have done to make sure that we possibly obtain a good data. The performance testing has been done at National Space Agency (PAN), Sg. Lang, Banting Selangor by connecting to the CALLISTO spectrometer. In this case, we choose input impedance, R0 = 50 ohm for this LPDA antenna. We also select element factor (τ) and spacing factor (σ) give in the subtended angle of 3.43 degrees. As a result, a bandwidth ratio (B = 870 MHz /45MHz) of 19.33 gives a bandwidth as 2.14. The power flux density of the burst is 4.53841 × 10-21 W/m2Hz. From the evaluation, we found that the signal to noise ratio is 3.9 dB. Although there are still needs to be improved, this construction of LPDA is considered successful and suitable for to observe the Sun activities at low frequencies.

Effect of light pollution on night sky limiting magnitude and sky quality in selected areas in Malaysia

We investigate the effect of light pollution as the important considerations that limits the quality of the sky brightness for the astronomical purpose. Selected sites that covered: Klang, Selangor, Merlimau Melaka, Ipoh, Perak ad Kuala Lipis, Pahang, Malaysia have been chosen in order to investigate the visual estimation magnitude for observing visible stars. The results also based on Bortle scale theory provides glimpses of potential quality of night sky quality that is currently lost in most urban area in Malaysia. From the results, Kuala Lipis, Pahang is the best candidate site for astronomical purpose with the range of magnitude from 20.3 till 21.5 magnitudes per arc second. Some recommendation for a better solution will also be discussed.

An Automated System for Signal Detection of Solar Radio Burst Type II Due to Coronal Mass Ejections Phenomena

This paper presents the signal detection by automated system for an event related to solar phenomena. Here, a system of Compound Astronomical Low-Cost Low-Frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) for detecting, interpreting and observing automatically radio signal obtained from solar activity is been used. The system observes and collects radio signal for every day via internet and stored in a central data and it is a worldwide network of radio spectrometer where has been installed in various locations all over the world. An event detects by the CALLISTO on 2nd November 2014 in Blein, Switzerland shows the present of solar radio burst type II due to Coronal Mass Ejections (CMEs). The Log Periodic Dipole Antenna (LPDA) was connected to the CALLISTO system software to collect the signal of solar activity. LPDA monitors solar radio flux in due to solar radio burst type II phenomena. It standardized the frequency range for CALLISTO networking to operate well. CALLISTO system has already proven to be a precious new tool for monitoring solar activity and for space weather research.

The significance of e-CALLISTO system and construction of log periodic dipole antenna (LPDA) and CALLISTO system for solar radio burst study

The solar radio burst data by using the e-CALLISTO (Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy in Transportable Observatory) network is presented. This project is an alternative to support new country that interested in solar astrophysics. Until now, there are 45 sites used the same system over the world. In this system, we are monitor the solar activity in the range of (45- 870 MHz) using a Log Periodic Dipole Antenna (LPDA). The International Space Weather Initiative (ISWI) program was conducting this project in order to observe the solar activities within 24 hours per day and a portable LPDA were designed which suitable with the criteria with boom length size of the antenna. The rod has gain about 7.01 dB and has 19 elements which made up by two (2) aluminums rods. The rod aluminum are built in order to signify different frequencies. The gain of the antenna is very important for preamplifier to amplify the signal of the sun. There are some suggestions on improving design also presented.

The international cooperation of solar radio burst project using e-callisto system network

The CALLISTO (Compound Low Cost-Low Frequency for Transportable Observatories) system is one of the most outstanding project under ISWI with there are more than 80 instruments in more than 43 locations with users from more than 116 countries. In this paper, we will highlight the concept of CALLISTO, distributing the observational sites all over the world and how this system is become as one of the efficient solutions to achieve the 24 hours radio observation. This innovative project is to monitor the Sun at the radio frequency range, which is very important to understand the solar flare and Coronal Mass Ejections correspond to different aspects of the same magnetic energy release. Malaysia also occupies an important role in the CALLISTO due to the 12 hours monitoring of solar activities throughout the year. Since 2007, the e-CALLISTO system has already proven to be a valuable new tool for monitoring solar activity and for space weather research.