SV9482: What does the Signal Level Indicator (SLI) do?

The Signal Level Indicator (SLI) shows the current strength of signal received, represented by three different levels of blue LEDs lighting up at the front of the aerial. A strong signal is represented by all blue LEDs lighting up; a weak signal is represented by one LED lighting up.
By moving the aerial's direction and position you can find the best reception in your room.