Overlap in subsequent passes

[Fan Ellis]

Hello,

Is there any way to change the step for Pass 2-4 in FFT window deformation PIV analysis?

Thank you.

Kind regards,

Ellis

[William Thielicke]

Hi, overlap is fixed to 50% because that made programming for me quite a bit easier.

[Phil Kreth]

I'm pulling up an old thread here, but I'm curious if it would be possible to have control over the overlap / step size of the subsequent passes. I'd even be fine with replicating the overlap percentage from the first pass through the subsequent passes. I've looked into what I might need to modify to get either of those things to work, and I can see how the hard-coding choice of 50% definitely made it easier lol. 

Thanks,

Phil

[Abdul Samad Saleem]

Hi All!

Can you give some comments on the choice of Interrogation Area (IA). 

The concept of IA > (4 * particle displacement) is for Pass 1, Pass 2 or 3?

Thanks,

Abdul Samad

[William]

Hi, this rule is for pass one. Another rule says that there should be 5-8bpartucles per interrogation area. But it is a trade-off between noise and resolution. The latest beta can assess the measurement uncertainty, this might be helpful:

https://github.com/Shrediquette/PIVlab/archive/refs/heads/main.zip