@DarkStar Any chance you can call him out on saying the beam isn't diverging and then comparing a hit on the board (c5) and a hit on the retro reflective patch (c16)? (Page 6, just before his response to you)

Check my post

#126 I think I addressed the beam spread pretty clearly with this:

I also called him out about C5 and C11 which are hits on the

**same spot **on the boat but they give two different heights - that is pretty busted (which Boxer noted also).

I knew the data was bad but hadn't realized just how completely fraudulent their data was (at least in the sense of it being unjustifiably wrong, not necessarily knowingly and on purpose but with negligent disregard for care in measurement at the very least) How can you measure the height to the same few spots on the boat and not realize you are giving two different values for it?

I'm trying to build a montage of reflection spots showing how they are exactly the same few spots on the boat but they give ever increasing heights for those same spots.

I'm also working on a revised spreadsheet which accounts for beam spread (and maybe refraction if it seems necessary). One challenge I'm facing is that the beam spread is clearly non-linear so a simple 'divergence' measure doesn't work. You can see this very clearly in the above series -- estimate beam size and calculate divergence angle from that and you get different values at every measurement point. So I need to redo that with much more care and capture my measurements so I can model the laser beam spread better. By C2 I estimated about .24mrad but by C5 I was getting 0.7 mrad. I'm using a 100mm starting aperture (~4 inches) if anyone else wants to try.

What I want to show is that the observed beam spread from C2-C11 is sufficient to account for the remainder of the reflective hits on the camera lens/reflector on jacket/chrome support bar.

So basically filling out this Excel and fitting a curve to the divergence data...

WARNING THIS IS WORK IN PROGRESS, NOT FINAL DATA (for example - the measured, beam widths are needed and then fitted to a curve before the final data is meaningful in any way).

The first three rows are useless because they were still moving the laser angle so I've blotted them out as a reminder.

Let me know what you think about this approach (and if someone wants to try to estimate the beam widths that would be awesome, to get a cross-check -- I know that a rough estimate is all we can do).

I'm also working on fine-tuning the beam width calculation.