Target identification by time constant

[Tinkerer]

With a traditional PI we measure the amplitude of the target response.
Much is to be gained by measuring also the target TC.
The best way to do this would be by digital signal processing. However, I found that a programmer needs to understand a function well in order to write good code for it. How do we describe the method of measuring the TC of a target?
We could experiment a bit with analog methods first and once we have a proper defined method, find someone who can implement it in DSP.

Opinions are welcome.

[Thomas]

Something like this?

[Tinkerer]

Something like this? [ATTACH]27920[/ATTACH]

Right, good idea.

I can think of at least 2 more ways, but thinking outside of the box there are probably several more ways. We should try every possible way to find the best.