I am absolutely blown away by this thread. I was working on TDR via VNA, but had not started to write any code. Just looking at the mathematics very closely. Particularly because of the manner in which the problem is treated in Dunsmore's book, which has a strong "Professionals at work, don't try this yourself." tone.
Clearly the basic work is done, so I am changing direction and will focus on crafting test cases. I spent much of my career in the oil industry finding and fixing bugs in 2.5 million lines of seismic processing codes. The oil industry seismic community was doing DSP almost 20 years before EE started doing it. We could make money with a 125 Hz Nyquist. Digital processing was *much* easier than doing it on analog data. So Geophysical Services Incorporated, the parent company of Texas Instruments, threw huge sums of money at TI to figure out how to make the data acquisition equipment. Eventually TI sold GSI which later shut down for lack of revenue during one of the downturns.
The resolution for TDR work is a function of the maximum frequency and the phase resolution. I don't yet know if we can wedge an FFT into flash or not. I've got a prime factor FFT algorithm which is probably 2 dozen lines of FORTRAN, so it might be possible. But at $35 delivered from China, writing TDR only FW would make it a *very* useful tool worth having for even occasional use.
I've got some chores to do and you're all running *very* fast. I'll try not to fall too far behind, but it's likely to take me a while to catch up. Kirkby talking me into getting one of these when we were chatting on the phone and Dave was right. Wow! It is a tour de force of T&M design.
Have Fun!
Reg
