Real time solar observations in Metsähovi Radio Observatory
Metsähovi Radio Observatory observes Sun in real time with two different
instruments: a 1.8-metre dish at 11.2 GHz and two Callisto radio
spectrometers at 50-890 MHz. These instrument are mainly focused to observe
solar radio bursts. In addition solar radio maps are made on daily basis
with a 14-metre dish at 37 GHz.
On below is shown current radiation intensity of the Sun at 11.2 GHz from
the sunrise. Spikes above the normal level (4-5 V) indicates solar radio
bursts, respectively spikes below the normal level are due to the bad
weather conditions (rain or snowing etc.). The emission at 11.2 GHz comes
from the low corona. The spike at 09:00 or 10:00 UT is due to a daily
calibration.
On below is shown current radiation intensity of the Sun at two different
Callisto frequencies (221 and 353 MHz) from the sunrise. The emission at
meter wavelenghts comes from the high corona. The lower frequencies are not
so sensitivity for the weather conditions, but they are more vulnerable for
RFI (Radio Frequency Interference). Thus there is more variability in
observed signals. Clear spikes above background indicates the solar
flares, and even more reliable if they match at 11.2 GHz spikes.
Solar radio emission has for instance a direct impact to HF radio
communications. It can cause attenuation to radio signals due to
absorption and, in the worst situation even radio blackouts are possible.
The current absorption situation is presented in map below More on this
can be found:
http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.
Credit: SPACE WEATHER PREDICTION CENTER, NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION