SRS Data Examples A brief overview of some types of radio emissions observed on the Solar Radio Spectrograph

Overview w The following slides show examples of actual SRS displays observed at the Learmonth Solar Observatory, and are labelled to indicate various phenomena of interest.

Typical non-solar signals that might be seen

This type of signal is local interference

Electrical storms may occur in summer and afternoon hours

Meteors are seen as echoes from distant transmitters, often in the FM band. They may appear as dots, or short vertical lines, if several transmitters are involved.

Each day, a minute after startup, the SRS system automatically performs a self calibration, which is seen as a sequence of vertical bars.

This view shows a series of type III (fast drift) solar radio bursts. These are the most common type of radio signal produced by the Sun.

This is a view of two type II (slow drift) solar radio bursts. Type II bursts are much less common than type III bursts, and it is very rare to see two sequential intense type II’s like this.

w The next two slides illustrate the difference in background noise level that can occur between times of low and high density ionospheres. (eg solar minimum and solar maximum conditions).

This shows a very clean display, with almost no ionospherically propagated signals apparent in the lower frequencies.

This display, around solar maximum (cycle 23), shows a large mass of ionospherically propagated (HF) signals in the lower frequencies. The mass of colour around 27 MHz is from Indonesian CB traffic. We also see solar type III activity.