Map of current distribution of Callisto instruments in July 2016
Red triangles: locations provide data, orange star: locations do not provide data yet/anymore
Statistics: more than 121 instruments in more than 67 locations with users from more than 129 countriesCallisto stands for: Compound Astronomical Low cost Low frequency Instrument for Spectroscopy and Transportable Observatory
Type II burst (Ooty)
The CALLISTO spectrometer is a programmable heterodyne
built in the framework of IHY2007 and ISWI by former Radio and Plasma
Physics Group (PI Christian
Monstein) at ETH Zurich, Switzerland. The main applications are
observation of solar radio bursts and rfi-monitoring for astronomical
science, education and outreach. The instrument natively operates between
45 and 870 MHz using a modern,
commercially available broadband cable-TV tuner CD1316 having a
frequency resolution of 62.5 KHz. The data obtained from CALLISTO are
FIT-files with up to 400 frequencies per sweep. The data are
transferred via a RS-232 cable to a computer and saved locally. Time
resolution is 0.25 sec at 200 channels per spectrum
pixels per second). The integration time is 1 msec and the radiometric
is about 300 KHz. The overall dynamic range is larger than
For convenient data handling several IDL- and Python-routines were
Many CALLISTO instruments have already been deployed, including: 5 spectrometers in India (2 in Ooty, 1 in Gauribidanur, 1 in Pune, 1 in Ahmedabad), one in Badary near Irkutsk, Russian Federation, two in South Korea, three in Australia (Perth, Melbourne and Heathcote), two in Hawaii, two in Mexico, one in Costa Rica, two in Brazil, three in Mauritius, 5 in Ireland, one in Czech Republic, two in Mongolia, four in Germany, two in Alaska, two in Kazakhstan, one in Cairo, one in Nairobi, one in Sri Lanka, three in Trieste, one in Hurbanovo/Slovakia, two in Belgium, two in Finland, 8 in Switzerland, one in Sardinia, 4 in Spain, 5 in Malaysia, 3 in Indonesia, one in Scotland/UK one in Roztoky/Slovakia, one in Peru, one in Rwanda, one in Pakistan, 2 in Denmark, one in Japan, one in South Africa, two in Greenland, two in Austria and one in Uruguay. Through the IHY/UNBSSI and ISWI instrument deployment program, CALLISTO is able to continuously observe the solar radio spectrum for 24h per day through all the year. All Callisto spectrometers together form the e-Callisto network. Callisto in addition is dedicated to do radio-monitoring within its frequency range with 13'200 channels per spectrum. The frequency range can be expanded to any range by switching-in a heterodyne up- or a down-converter.
Instrument deployment including education and training of observers was financially supported by SNF, SSAA, NASA, Institute for Astronomy and North-South Center of ETH Zurich and a few private sponsors.
Data access is free for everybody but we would appreciate credit to the Institute for Astronomy, ETH Zurich, and FHNW Windisch, Switzerland.
For papers containing data of the e-Callisto network, I -as the instrument PI- expect to play the role of a co-author as recommended
by ISWI, UN-office for outer space affairs in Vienna.
Adress for co-authorship here: Monstein
RFI-map, derived from FIT-files. Color is proportional to the skewness of a 2-dimensional FIT-file. Data present the 200 best channels out of 13'200 possible channels of the frequency range of Callisto. This plot is kind of optimistic case in terms of rfi.
Skewness, derived from FIT-files which is a selection of the best 200 channels out of 13'200 possible channels.
RFI-map, derived from spectral overview. Color is proportional to (mean-rfi - quiet Sun flux), so it's a measure for minimum antenna gain to observe quiet Sun at current rfi-level. Spectral overview takes into account all possible 13'200 channels in the whole spectrum of Callisto.
Y-axis shows the average minimum antenna gain which is required to observe the quiet Sun at local mean level of rfi.