Measuring Wave Propagation speed

Hello All,

I am a research student who is constantly looking for ways to get better at ImageJ. I have been looking at small combustion phenomena, and I personally want to study the flame waves created by these experiments! Specifically, I want to measure the propagation speed of the flame front. There are usually 3 kinds of waves.

  1. Fuzzy boundary, very slow, horizontal wave
  2. Fuzzy boundary, decent speed, wave expands outward circularly
  3. Clear boundary, fast, wave expands outward circularly

My goal is to find a decently accurate/repeatable method to measure the speed of these three waves individually and in a timely manner (as I want to do this for many many cases)
A macro with some/minimal user input would be Ideal, but any process that does not require me to get x,y locations frame by frame would help.

Some of my current ideas

  1. Threshold the wave, find it’s centriod x,y and do this frame by frame to see it’s movement over time. Maybe a macro that would automatically do next slide after I click on the waves location.
  2. Draw a line along the path the wave follows, and see how far up the line it gets each frame. (not sure how to macro this one)

My current technique takes too long:

Thanks for any and all input.
Sincerely,
Vasko :slight_smile:

Hi,

you can do manual tracking in TrackMate for example: https://imagej.net/Manual_tracking_with_TrackMate

Thank you! I overlooked this in the past. I was curious if there was a plugin designed specifically for waves but this will have to do.

-Vasko

Maybe you could do this analysis: https://imagej.net/Helmholtz_Analysis
if you generate a zprojection or with a kymograph?

But take care with the time sampling… insufficient sampling leads to aliasing. https://en.wikipedia.org/wiki/Nyquist–Shannon_sampling_theorem