Callisto spectrum measurements in Badary (Russian Federation)

2016

Abstract. This report documents part of a planned measurement campaign in which spectrum measurements were done at different locations in the mountains in Switzerland. The results of a study in Via Mala Gorge carried out in August 2007 are presented and compared with Bleien observatory. The spectrum measured in a Gorge are expected to have reduced low frequency RFI due to refraction around the high gorge walls, and Via Mala was chosen as a test site as it is easily accessible. Measurements were carried out with a broadband omni-directional antenna connected to a Callisto spectrometer designed and built in ETH Zurich (Benz, 2004). This study indicates that the interference in the gorge is not significantly lower than otherwise in the frequency range below 1GHz (λ>30cm), thus Via Mala is not ideal for broadband spectroscopic solar radio astronomy observations. It also suggests that the reduction of interference within natural cavities in general is not very significant. Key words. ...

2012

Abstract. During a measurement campaign in May 2006 spectrum measurements were done at Humain station in Belgium. Humain is part of the ROB (Royal Observatory of Belgium) located south of Brussels, capital of Belgium. Measurements were done with a broadband logarithmic periodic antenna connected to a Callisto spectrometer designed and built by ETH Zurich, see (Benz, Monstein and Meyer, 2005). This measurement campaign shall be the technical basis to decide how to continue concerning fixed frequency measurements and also spectroscopic measurements below 1GHz. The results are presented in total overviews as well as in form of a digital zoom on the most interesting frequencies ranges. An extreme difference in polarization was detected. While horizontal polarization leads to acceptable results, vertical polarization can not be used by Callisto spectrometer because the power level is too high and therefore produces cross modulation. Key words. Callisto, spectrum, polarization, cross modu...

This report documents part of a planned measurement campaign in which spectrum measurements were done at different locations worldwide. The results of the KASI observatory site in Daejeon which was studied in October 2007 are presented. Measurements were carried out with professional broadband logarithmic periodic antenna connected to a Callisto spectrometer designed and built in ETH Zurich (Benz, 2004). This study provides the technical basis to decide whether it is possible to do spectroscopic measurements below 1GHz (λ > 30cm) in Daejeon. The results are presented, compared with Bleien observatory and displayed as digitally zoomed spectrums focusing on interesting frequency bands allocated for radio astronomy and other passive services. In terms of electromagnetic interference, Daejeon is worse than Bleien and thus not ideal for broadband spectroscopic solar radio astronomy observations. However, it is sufficient for small band width studies: to detect CME's or to measure quiet solar radio flux at dedicated frequencies. Such narrow band studies would probably be no better than is already possible in Bleien.

2016

Abstract. This report documents part of a planned measurement campaign in which spectrum measurements were done at different locations worldwide. The results of the KASI observatory site in Daejeon which was studied in October 2007 are presented. Measurements were carried out with professional broadband logarithmic periodic antenna connected to a Callisto spectrometer designed and built in ETH Zurich (Benz, 2004). This study provides the technical basis to decide whether it is possible to do spectroscopic measurements below 1GHz (λ> 30cm) in Daejeon. The results are presented, compared with Bleien observatory and displayed as digitally zoomed spectrums focusing on interesting frequency bands allocated for radio astronomy and other passive services. In terms of electromagnetic interference, Daejeon is worse than Bleien and thus not ideal for broadband spectroscopic solar radio astronomy observations. However, it is sufficient for small band width studies: to detect CME’s or to mea...

During a planned measurement campaign in April 2007 spectrum measurements were done at different locations in canton Ticino Switzerland. This report describes the results of IRSOL observatory site above Locarno. Measurements were done with different broadband logarithmic periodic antenna connected to a Callisto spectrometer designed and built by ETH Zurich . This measurement campaign shall be the technical basis to decide how to continue concerning spectroscopic measurements below 3GHz (λ > 10cm). The results are presented, compared with Bleien observatory and discussed in form of digitally zoomed spectrums in the most interesting frequency bands allocated for radio astronomy and other passive services. In terms of electromagnetic interference Locarno is worse than Bleien and thus not ideal for spectroscopic solar radio astronomy observations. But it is sufficient for single frequency observations on dedicated frequencies to determine quiet solar radio flux.

A solar radio spectrometer CALLISTO was installed in December 2011 in the Slovak Central Observatory in Hurbanovo in the frame of the ISWI (International Space Weather Initiative) program. The spectrometer registers solar radio radiation using a broadband antena in the range of frequencies from 45 to 870 MHz. This contribution presents the observing site of the instrument and the first results.

IEEE Antennas and Propagation Magazine, 2014

The Compound Astronomical Low-Cost Low-Frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) is a worldwide network of radio spectrometers designed for 24-hour solar observation. It is a collaboration among the Swiss Federal Institute of Technology Zurich and numerous local host institutes, spread out around the world. This paper presents an overview of the CALLISTO spectrometer system at the Universiti Kebangsaan Malaysia (UKM).

During a measurement campaign in May 2006 spectrum measurements were done at Humain station in Belgium. Humain is part of the ROB (Royal Observatory of Belgium) located south of Brussels, capital of Belgium. Measurements were done with a broadband logarithmic periodic antenna connected to a Callisto spectrometer designed and built by ETH Zurich, see . This measurement campaign shall be the technical basis to decide how to continue concerning fixed frequency measurements and also spectroscopic measurements below 1GHz. The results are presented in total overviews as well as in form of a digital zoom on the most interesting frequencies ranges. An extreme difference in polarization was detected. While horizontal polarization leads to acceptable results, vertical polarization can not be used by Callisto spectrometer because the power level is too high and therefore produces cross modulation.

2019 IEEE MTT-S International Microwave and RF Conference (IMARC), 2019

This paper presents a detailed description of various subsystems of CALLISTO solar radio spectrograph installed at the USO/PRL. In the front-end system, a log periodic dipole antenna (LPDA) is designed for the frequency range of 40-900 MHz. In this paper LPDA design, its modifications, and simulation results are presented. We also present some initial observations taken by CALLISTO at Udaipur.

2007

During a measurement campaign in winter 2006 spectrum measurements were done at difierent locations in India. This report describes the results at Gauribidanur radio telescope site. Measurements were done with a broadband logarithmic periodic antenna of the site connected to a Callisto spectrometer designed and built by ETH Zurich (Benz, 2004). This measurement campaign shall be the technical basis to decide how to continue concerning spectroscopic measurements below 1GHz with existing antennas and/or new ones. The results are presented, compared with Switzerland and discussed in form of digitally zoomed spectrums in the most interesting radio astronomy frequency ranges.