scholarly journals Radio Frequency Interference Measurements for a Radio Astronomy Observatory Site in Indonesia

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 51
Author(s):  
Peberlin Parulian Sitompul ◽  
Timbul Manik ◽  
Mario Batubara ◽  
Bambang Suhandi

We report on the measurements of radio frequency interference (RFI) at Mount Timau, Kupang, Indonesia, which is intended to host a future radio astronomy observatory. These measurements were taken twice in October 2020 and December 2020 to obtain the RFI environment, at frequencies between 70 and 7000 MHz. Due to the limitations of the measurement data, the results presented in this paper are based on peak detection rather than statistical analysis. Based on the measurement results, the frequency interval between 70–88 MHz and 120–150 MHz is relatively quiet, and the frequency range of 150–300 MHz is relatively clear. The frequency interval of 300 to 800 MHz is relatively quiet, except at the frequency of 600 MHz. The frequency range of 800–1400 MHz is also relatively quiet. The predominant terrestrial services in this band are at 840 MHz, with an amplitude around 32 dB, and 916 MHz, with an amplitude around 12 dB, and the global system for mobile (GSM) signals around 954 MHz have an amplitude around 20 dB above the noise floor. The frequency range of 1400–7000 MHz is also relatively quiet. In this band frequency, we can see RFI at 2145 and 2407 MHz, emitted by local Wi-Fi, and at 2683 MHz, with amplitudes of 18, 40 and 15 dB, respectively, from the noise level. We conclude that, for this period, the frequency band allocated for astronomy can possibly be used for radio telescope development.

Author(s):  
S. J. Tingay ◽  
M. Sokolowski ◽  
R. Wayth ◽  
D. Ung

Abstract We present the first survey of radio frequency interference (RFI) at the future site of the low frequency Square Kilometre Array (SKA), the Murchison Radio-astronomy Observatory (MRO), that both temporally and spatially resolves the RFI. The survey is conducted in a 1 MHz frequency range within the FM band, designed to encompass the closest and strongest FM transmitters to the MRO (located in Geraldton, approximately 300 km distant). Conducted over approximately three days using the second iteration of the Engineering Development Array in an all-sky imaging mode, we find a range of RFI signals. We are able to categorise the signals into: those received directly from the transmitters, from their horizon locations; reflections from aircraft (occupying approximately 13% of the observation duration); reflections from objects in Earth orbit; and reflections from meteor ionisation trails. In total, we analyse 33 994 images at 7.92 s time resolution in both polarisations with angular resolution of approximately 3.5 $^{\circ}$ , detecting approximately forty thousand RFI events. This detailed breakdown of RFI in the MRO environment will enable future detailed analyses of the likely impacts of RFI on key science at low radio frequencies with the SKA.


1997 ◽  
Vol 161 ◽  
pp. 661-666
Author(s):  
Peter R. Backus ◽  
Sam LaRoque ◽  
Jill C. Tarter ◽  
John Dreher ◽  
Kent Cullers ◽  
...  

AbstractFrom February through early June, 1995, Project Phoenix conducted SETI observations of 209 stars over the frequency range from 1195 to 3005 MHz. A byproduct of this search is a unique data set suitable for studying the Radio Frequency Interference (RFI) environment at the Parkes 64-m telescope in New South Wales, Australia. RFI is an increasing problem for SETI and other radio astronomy observations conducted outside of the «protected» frequency bands. The data analyzed for this paper were «mean baseline» spectra in Left and Right Circular Polarization (LCP, RCP), integrated for either 138 or 276 s, covering a 10 MHz bandwidth with 15,552 channels at a resolution of 643 Hz. Channels were identified as contaminated by RFI when the power in the channel exceeded the mean noise by 3%. The «spectral occupancy», the fraction of time RFI was seen, was determined for each channel. The RFI occupancy for LCP and RCP are distinctly different. Approximately 100 MHz of the spectrum was too heavily contaminated for SETI observations.


2011 ◽  
Vol 33 (1) ◽  
pp. 1-26 ◽  
Author(s):  
İbrahim Küçük ◽  
İpek Üler ◽  
Şükriye Öz ◽  
Sedat Onay ◽  
Ali Rıza Özdemir ◽  
...  

1991 ◽  
Vol 112 ◽  
pp. 190-193
Author(s):  
G. Swarup ◽  
T.L. Venkatasubramani

ABSTRACTA Giant Meterwave Radio Telescope (GMRT) is being set up at Khodad about 80 km north of Pune in India for operation in the frequency range of about 30 to 1500 MHz. It is to be completed by 1992 and is being designed to investigate many outstanding problems in the fields of galactic and extragalactic astronomy. We present here measurements of man-made radio frequency interference (RFI) conducted at the GMRT site in 1985 and 1988. It is seen that highly sensitive radio astronomy observations can still be made at selected bands in the above frequency range because of the relatively low level of RFI in India. However, this advantage may not remain for more than a decade or two.


1968 ◽  
Vol 21 (1) ◽  
pp. 87 ◽  
Author(s):  
RF Haynes ◽  
PA Hamilton

Recent observations of 31 radio sources in the frequency range 40-130 MHz obtained at the Australian National Radio Astronomy Observatory, Parkes, N.S.W., are reported in this paper. The results obtained show that some useful information about source emission mechanisms may be deduced


2013 Africon ◽  
2013 ◽  
Author(s):  
Domingos Barbosa ◽  
Miguel Bergano ◽  
Valerio A. R. M. Ribeiro ◽  
Anita Loots ◽  
Venkatasubramani L. Thondikulam ◽  
...  

2012 ◽  
Vol 8 (S291) ◽  
pp. 208-208
Author(s):  
Augustine Chukwude

AbstractWe investigate the spin-down behaviour of a sample of 25 radio pulsars on decadal timescales (~ 18 years) using a continuous timing data obtained over a period of at Hartebeesthoek Radio Astronomy Observatory (HartRAO). Particular attention is placed on achieving a better time resolution of both the short-term and long-term changes in pulsar spin-down using local phase-coherent measurements of the spin-down rates (). We demonstrate that the spin-down of radio pulsars is generally complicated by a superposition of processes that may or may not be related. Specifically, our results show that (i) for 7 pulsars, the observed spin-down variation is largely stochastic, characterized by random and sustained jumps in of varying amplitudes, (ii) for 9 objects, the spin-down evolution shows dominant monotonic variations in superimposed on short-term stochastic jumps in the parameter, and (iii) for the remaining 9 pulsars, the long-term spin-down evolution is non-monotonic, dominated by some systematic excursion in the measured spin-down rates.


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