How can I analyze the waveform in the picture and determine that it is a second pulse signal?

I understand that a second pulse is a pulse signal with a frequency of 1Hz and a period of 1 second, which is difficult to observe on an ordinary oscilloscope because the period is too long, unless the pulse width is adjusted to a very narrow range, such as 0.1~0.2 seconds, and the oscilloscope's scanning time is adjusted to the longest possible range, which should allow you to see one burst pulse per second.