The pulse is filled with zeros in the blue marked area.
Areas of our impulse can be quickly erased to analyze the remaining part.
We see a reflection in our measurement after 3ms. We put the left marker exactly in front of the reflection, zoom out, put the right marker at the very end and fill with silence. (see below in the time domain graph where the curve becomes red between 0.064 and 0.066)
You get a kind of rectangular windowing around our impulse as it was classically used in other traditional programs. It can be used to analyze the high frequency range in order to observe the reflection-free direct sound without smoothing, but it loses the information in the low frequency range.
In contrast to this, there is the “ Frequency dependent window ” function which adapts dynamically to the required resolution.