How programmable delay line will increase the resoultion

[abhivani1411]

Fortsetzung der Diskussion von TDR (Time-domain reflectometer) concept. On the right track?:

@dc42

Then I was going to use a programmable delay line to provide about 0 to 45ns delay to the outgoing pulse in 5ns steps, thereby increasing the resolution to 5ns, which is about 0.5m of cable length

Hello ,
Could you please tell me if we use programmable delay line, it will increase the time delay in ns, but we need to decrease the time in order to increase the resolution. I am aware that an Arduino won't be able to count that quickly.
Thank you

[Idahowalker]

If you use more delay time then the delay time will increase. The Uno can give 4/5uS (micro) resolution. The ESP32 can do 12.5nS resolution.

[abhivani1411]

Yes I know that, but did you get my point? In that thread if you see it is written that delaying the time will increase the resoultion. That I didn't understand.
Thanks

[Idahowalker]

For my pulse induction metal detector delaying the sample time removes unwanted noise such as the earth's magnetic field, which increases resolution. Of course, delaying the signal sample time for too long decreases resolution.