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G.N. Rajasekhara Girish Kumar Beeharry Mauritius Radio Telescope. The CALLISTO spectrograph in Mauritius. Outline. · First Antenna · Back end · Commissioning · First flare · Subsequent flares · Observations from other CALLISTOs · Future work. The First Antenna.
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G.N. Rajasekhara Girish Kumar Beeharry Mauritius Radio Telescope The CALLISTO spectrograph in Mauritius
Outline • · First Antenna • · Back end • · Commissioning • · First flare • · Subsequent flares • · Observations from other CALLISTOs • · Future work
The First Antenna Broad band logarithmic periodic antenna at MRT site. The antenna was built out of standard aluminum profiles in the local workshop. Frequency range goes from 20 MHz up to 860 MHz in fixed vertical position Vertical tubes on both sides are made of PVC to mechanically support long, heavy dipoles..
The Back End The CALLISTO spectrometer is on the left side of the table (below ‘Toblerone Chocolate bar), power supplies just behind and monitor with keyboard and PC on the right.,
Commissioning (27.04,2009) X-axis shows time expressed in UT, Y-axis frequency in MHz and Z-axis denotes the stored digital value of the ADC(without any calibration). The frequency resolution is ~ 4 MHz and time resolution is 250 msec (4 sweeps Per second). Data is stored in 15 min FITS files
Quiet Sun: with background (08-10-2009) 45 MHz 860MHz 15 minute time interval (UT)
Quiet Sun: background subtracted (08-10-2009) 45 MHz 860MHz 15 minute time interval (UT)
Active sun having sunspots: with background (24-09-2009) 45 MHz 860MHz 15 minute time interval (UT)
Active sun having sunspots: with background subtraction (24-09-2009) 45 MHz 860MHz 15 minute time interval (UT)
Zoom in Active sun having sunspots: with bkgrnd subtraction (24-09-2009) 45 MHz 860MHz 15 minute time interval (UT)
“First light” flarZoom in Active sun having sunspots: with bkgrnd s092009)e ( 2009) Mauritius 45 MHz 860MHz 15 minute time interval (UT)
“First light”close up May 1st 2009 Mauritius 45 MHz 860MHz 15 minute time interval (UT)
Solar flare (6th May 2009)Mauritius 45 MHz 860MHz 15 minute time interval (UT)
Solar flare (8th May 2009) Mauritius 45 MHz 860MHz 15 minute time interval (UT)
Zoom in Solar flare (8th May 2009) Mauritius 45 MHz 860MHz 15 minute time interval (UT)
Solar flare (8th May 2009) other stations Bleien Humain
Solar flare (8th May 2009) other stations Kasi Mauritius
Solar flare (8th May 2009) other stations Ooty lin pol1: Lightning flash at 08:09:01.5 UT Ooty lin pol 2:Lightning flash at 08:09:04 UT
Zoom in Solar flare (24th Sep 2009) Mauritius 45 MHz 860MHz 15 minute time interval (UT)
Future Work Antenna array: improved gain & sky coverage Calibration Timing experiments - Software development Excellent first instrument for radio astronomy: Interested?