I am trying to understand the theory of operation of a time domain reflectometer (TDR).
TDR is a time domain instrument with measurement the impedance versus the distance. If with a VNA one can measure s-parameters, then with TDR one measures impedance.
Why would TDR be called S-parameters measurement method?
Ok, if I know the impedances, then I can create matrix U= Z I, where Z and I are matrices. But How I can use TDR for S-parameter measurement?
I have found the some slides (enter link description here)
pictures from this pdf: