The CALLISTO Solar
Radio Observatory is established in the Arthur C Clarke Institute (ACCIMT),
Colombo, Sri Lanka. The location of the CALLISTO system is 6o 47’
37’’ N, 79o 53’ 53’’ E at an
altitude of 40 m and the time zone is +5.30 from UT. The log-periodic antenna was
completely designed by the ACCIMT and constructed locally. Design constant (t) 0.822
and the relative spacing (s) 0.149 give 7 dBi theoretical gain for the log – periodic antenna and
it covers the frequency range of 45 – 600 MHz with 18 dipoles. The theoretical
impedance of the antenna 58.3 Ω is well agreed with the impedance measured in
the entire frequency range. The total height of the antenna is 5.38 m and the
longest dipole is 3.33 m. The linear polarized antenna is pointing to zenith
and the dipoles directed to north-south direction.
The
pre-amplifier is made by ACCIMT using MAR-8ASM Monolithic surface mount
amplifier which gives 31.5 dB gain at 100 MHz.
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| The
members of astronomy division. From left; Saraj Gunasekara, Janaka Adassuriya, Kamal Perera, Indika Medagangoda. |
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| 1st ligth, a type III burst. X-axis is local time |
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| Rather crowded spectrum, nevertheless solar observations are still possible. |
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