What is "gated region" and "gate length" mean?

[yjiang]

I am programming a program about ultrsonic signal processing. A sentence in a reference said "To deconvolve the response of the measuring equipment from the backscatter data, a calbration spectrum (reference signal) is obtained by reflecting an ultrasonic pulse off a steel plate positioned in water at a distance corresponding to the center of the gated region." But I can not understand what's the last two words "gated region" mean. And a parameter in a formula is "gate length". I also do not know what is that in a waveform. Please gave me a help! Thanks alot!

[Alberto]

Hi,
an ustrasonic equipment generally has one or more gates.
A gate is a settable time window to define a portion of interest where you want to do the inspection.
A gate is displayed on the screen as an horizontal line and it is defined by: start point, gate width (length) and gate Y position.
From your post I understand your reference signal is the spectrum of the reflected echo when the ultrasonic probe is placed at a distance from the steel plate to have the echo in the center of a defined gate.
Let me know if this was clear enough, I've been dealing with ultrasonic inspections for more than a while,
Alberto

[yjiang]

Thank you very much for your helpful answer! I am programming on the ultrasonic backscatter coefficient measurement and is facing some problems. If you can help me something on this region? Thanks!

[Alberto]

Hi again,
I'd be glad to help you if able to.
You can detail your application and problems.
My e-mail is: altek@tin.it

Alberto