Andy,
Gary was referring to the waterfall view in zero-span mode. Once in zero-span mode use the “Add Measurement” button in the upper left of the application to add a water fall plot. It shows you a very dense spectrogram plot over the duration of the time domain capture, usually overlapping FFTs by 90% or more depending on settings.
In sweep mode, it’s just a matter of clicking the “spectrogram” checkbox in the upper left as well. Same general functionality, less overlap between lines in the plot as compared to zero-span.
Speaking of which, maybe we should be a bit more consistent in our naming.
All of our waterfall/spectrogram views are “flat” 2D plots, if that is what you were referring to.
Let me know if you have more questions.