I think you meant to say “second term” instead of “second factor”. No problem, I’m not a math person either. It would be nice to be able to use the average velocity, but the distance from the path of the bullet to where the recorder is located is important (the off-line distance).
Yes, that’s the simple formula of Tdiff = d/Vc - d/Va, where Va = avg. velocity
That works well when the recorder is not standing off from the path of the bullet. I needed to apply the snick-boom measurements to the Source 2 and Source 6 recorders. So, that’s why the more complex formula was necessary. And for Shot 10, I used the formula with the Podium mic because the report was overwhelmed by the snick (at approximately the t+13 ms point).
Why would you assume “average velocity is 94% of muzzle velocity”? Is this a well established general fact? I tried googling it but didn’t come up with anything. Wouldn’t that factor of 0.94 decrease as the distance from the shooter increased?