physicsman

Yup, your right.

I see. He does have a decent simulator. Another interesting thing that I'd like to look at in simulation is the fact that while a freeflyer will reach terminal quicker they will also have a shorter forward throw since the reduction of vertical drag usually means they are presenting a larger portion of their body, on average, to the relative winds and should come to rest relative to them quicker then a belly flier.

http://flic.kr/p/bBLy8m I have a fully functional skydiving code written up in MATLAB. It would be a bit time consuming but if it would help elucidate matters I can create some simple movies that show what happens to separation for any given arrangement of conditions. I think the main problem stems from the fact that most jumpers intuit skydiving by imagining the path during free-fall. The free-fall path is always misleading because you can change its shape by altering your frame of reference and it only tells you about one skydiver. The important picture that is reference frame invariant and harder to grasp is the time evolution of the line connecting any pair of skydivers. This picture gives you all of the relevant safety information and it doesn't change with respect to your vantage point.

Great post. I've been trying to explain this as well. With some difficulty at my local DZ

Anybody have a chance to try these models yet? Is the data rate above 1Hz?