Thank you for the article and your post, Vitalii.  It helped me to see what type of sensor they used (it was a capacitance level sensor) and a bit of the methodology they used.  Unfortunately I now realize that high-tech sensors like that, as well as others that might work like conductivity level sensors and ultrasonic sensors, are out of my project's budget.

I will likely resort to a simpler build by using fishing line and stringing small floats on them, then watching the floats as they bob up and down from the side of the tank.  If that fails, I may try using a reflective film on top of the water and rigging up a few lasers.

However, if anyone is aware of a software that could simulate the disturbance and collect the height-over-time data at select points, please don't hesitate to post.

Your idea of projection is great, Michael! I hadnt thought of that before.  I'll probably still need some reflective film on the surface of the water for that, but that should be simple to fabricate.

As for b), I dont know how putting a grid on the bottom of the tank would do any good; wouldn't that mean you'd have to view the tank from the top-down, in which case the tank would (ideally) appear still?

I'm not sure if Johnny Cash ever performed in my area in person, but I know a few months ago there was a Johnny Cash dedication concert/performance that was done at the folsom Harris Center of the Arts.

Correct, I was definitely not alive then =P

Good idea with the refraction, I hadn't thought of that either.  That would allow me to use standard lasers and not ones that measure distance, which is great money-wise.

The aim is to produce an automata similar to this video's (https://www.youtube.com/watch?v=ZqzjAmPFND8), but having the rings actually settle and represent an actual water droplet/pebble hitting water.  The video's version represents a harmonic wave, whereas I'm looking to make it actually diminish.

The idea is to measure the water surface's height over time at the location of each ring's radius, then get best-fit curve graphs from the data and get their equations.  Then, take those equations and make them wrap around a circle (a bit of fun polar math), and those would be me "cams" that would rotate via the crank arm (see attached image).  You can see that as the cam rotates, a following pin on top would raise and lower according to the equation.  Right now the Cartesian equation going around it is y=e^(-1.1x)(2)(sin10x).  I realize there are steep crevices in the "cam" that would be difficult to have the follower climb out of--I have this issue under control.

I have my build mocked up in Solidworks already, with the idealistic equations already wrapped around my "cams" (the diminishing sine waves).  The effect once I spin them looks cool, but definitely not realistic.  The goal is to get at least semi-accurate data to generate best-fit-curve equations that could then be used to make more accurate cams.

https://www.youtube.com/watch?v=ZqzjAmPFND8

As for whether or not I'm after capillary waves: I basically need to cause a disturbance in the water that is large enough that I can measure its resulting ripples/waves.  If I could manage to cause a slight disturbance (like a water drop), that would only create capillary waves, and yet still successfully measure the height of those capillary waves, that could be great.  So you're quite right, a film would alter the surface tension of the water; therefore, a film would be no good.

If the method of measuring works well, I hope to collect several batches of data--some from small disturbances, others from large ones, etc--so I could generate different sets of "cams" that can simulate different types of water motion.

And then if all methods of measuring fails, I'm left with manually tweaking my cam wave equations to try to make the rings look like water.