This is the report generated from Keysight ADS. I can see the reflections from the vias and layer change (impedance swing) but I couldn't figure out the impedance of the actual traces. Also, why are they using 5ns as time base?
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The graphs are directly showing the apparent impedance from the launch point (see vertical axis unit), relative to time since pulse launch.
Given the propagation speed, you can convert time into distance travelled (to reflection point and back for simple reflections).
In vacuum, 1ns ~ 30cm. Propagation on PCB depends of setup, but 0.6c is common, making 1ns ~ 20cm there and back.
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\$\begingroup\$ length added by vias? but more likely cables? I assume there is cabling between the keysight and the PCB and t=0 is the time the pulse left the instrument not when it reached the pcb \$\endgroup\$– MichaelCommented Aug 14 at 4:04