Big cliff height measurment????

[guest]

thanks for your concern,the whole thing isnt as gun ho and spur of the moment as I have have made out,when I ask a question I ask it as if I know nothing on the subject,that way you get a broader response and you get to reconfirm your own knowledge.
I understand the base communities concern and I am not going to lie and say this trip will not be dangerous,and possibly someone could die because of relatavly stepping into the unknown but this expedition has been two years in planning,using nothing but the best gear and the top climbers in the world.The people involved have a heavy training schedule for the year and the end result is basically edited by the people involved(one of whom is a film maker)
Additional to this,the main people involved have taken out insurance policies so that if there is a death the film will never see the light of day and the people who have put up the big bucks will get there money back.
This isnt a sunday afternoon sitting at the pub and saying `lets do this
Dont be concerned and please dont compare me to Rooney.
Thanks for the feedback though.
Simon Golding
Ps What height is this cliff your talking about and have you used a suit off it,would like to hear any info you have.

[guest]

>Dont be concerned and please dont compare
>me to Rooney.

We wouldn't dream of comparing you to Jason Rooney. Rooney had more experience than you and from what we've seen he had far more natural ability and talent as well.

If somebody had the same number of skydives as you have BASE jumps and they wanted to do a high altitude skydive would you recommend or encourage it?

Perhaps you should concentrate on advancing your BASE jump skills and numbers before attempting anything difficult. I'd recommend at least 500 BASE jumps off around 100 different objects as a good start.

Ego desire for fame limited experience = high chance of fatality.
Add high altitude and a minor gear problem to the equation and death is pretty likely.

Just because Glen lived through BASE climb with his 11 BASE jumps doesn't mean you will survive a similar experience.

Please don't let your desire for fame and recognition distract you from realistically evaluating your current skill level.

[guest]

2 things that I really hate(politics and bitching)especially in such a free minded sport full of very open minded people willing to push barriers and explore their own capabilities.Fortunatly you are the minority.
I am at a loss at where this attack has come from and why,what have I possibly done to you to warrant this?Have I jumped with you,did I crack onto your mother,What?Do you know how many objects I have jumped(I didn`t think so).
I have basically spent my whole adult life in the air,went solo in helicopters from 7 hours(is that enough) and went on within 6 months and flew commercially.Started skydiving and became an instructor within 1 year,Is that enough time,did I have enough jumps,you should tell me!Alot of people would say no until they found out the facts ,My students seem to be happy.
I was taught to BASE 3 years ago by someone who didn`t have hundreds,but did a brilliant job.
One thing I never do ,even now after thousands of
jumps is to think I am above people and stop listening to advice and stop learning,and that is exactly what I was trying to do with a technical question of how to measure a wall on a giant cliff.Should I know this after Blue Mountains?harbour bridge?Norway?
How often have you had to do this?Are you the person that should be doing this?Who is the world expert on jumping in thin air,It sounds like you!
As for ego and desire for fame,these are tall calls from someone who I do not know,If I had a large ego,I wouldn`t be asking for advice on the board and from friends involved in BASE.As for desire for fame,I am meerly doing as I want,something most people strive for.
You sound like you have a few hundred Base jumps but sadly you have a clouded mind,You sound as if you dont make a mistake,you sound almost perfect.
How do you evaluate someone on their ability?I have seen people with 200 jumps kick the arse of others with 1000,but they may not be able to spot.
Also I think the current world altitude record holder,Kittinger had 30 skydives when he jumped from 103000ft,mabye you should give him a call and tell him he is a fool?
I really do not know where you are coming from with this attack,I have no grevances with any jumpers.If you were generally concerned you would email me direct instead of public slandering,it is sad to see such bitching on a great information sharing board,there is alot of people here who have a lot of knowledge to share,you do not sound like one of them.
I am here for information,not to hear that I cannot base jump,I desire to be famous,have a big ego and I should not chase dreams.
BITCH SLAP YOURSELF because your a bitch!
Regards
SIMON GOLDING(Yes thats my real name)

[guest]

It seems like Concerned and others are concerned! It sounds strange that in a so big expedition there is no people able to answer all the questions you ask on the baseboard.

However, you do what you want and I assume you know what you are doing.

Just a few words to answer to your altitude problem (I'll compare sea level and 20000ft altitude behaviour):

- Air density is about half its value at sea level (typically 0.53)
- Terminal velocity will be multiplied by 1.39
- The time (to reach 97% of the terminal velocity) will be multiplied by 1.37
- The height (to reach 97% of the terminal velocity) will be multiplied by 1.94

Your will have the same feeling and control at terminal velocity but as it takes a longer time to reach this speed, a given time after the exit will provide you less control.

Using a wingsuit depends on what you want. You will still gain regarding time, speed, and height but differently than at sea level:
- The benefit regarding time (for a given height) is about 25% less than at sea level.
- The benefit regarding speed is about 20% greater than at sea level.
- The benefit regarding height (for a given speed) is about 20% greater than at sea level.

On an aerodynamic point of view, the similarity of the openning yields a greater time and height (same proportions than previous). The deceleration will be the same. But on a "mechanical" point of view, a greater opening time leads to a fuzzy opening. The vertical speed during landing depends on the aerodynamical characteristics of your canopy but will surely be greater.

If you want, I can provide you "formula's" if you or one of your guys is able to use it.

[guest]

Yes it does seem some people are concerned,but then again it seems people are concerned about alot of things other people are doing on this board!
No doubt there will be people with alot of knowledge on this trip,but unfortunatly they are not sitting around with me in my lounge rooom every night,they are in all corners of the globe ,we meet up for some high altitude training in a couple of months,it all goes back to trying to get as much info as possible.
Your information is excellent,I am not very mathimatically minded but I am willing to learn more.I would really like to hear of these formulas and also learn how these effects change as you go higher to say 25000ft.
On a final note for everyone reading,nobody here is perfect,we are all learning.I see things happen with more experienced and less experienced people than me go wrong and right,and I think to myself that I would have done things differently,but I dont judge them for it and certainly do not try and publically humiliate them for it.At least they are having a go.Give people respect and dont treat them like children.
Thanks again for all information supplied.
Simon

[guest]

You speak too much guy. Don't waste your time to justify yourself, ask your question and concentrate on what you need. Forget all other stuff. I don't care if you're able or not for the job. You do what you want. It's you to decide. Read only answers that give you objective informations to help you to decide. The BaseBoard is full of boring polemical messages.

Just a few equations:
The dynamic equation is a non linear differential equation:
dv/dt=-k.v**2 g
with
k=(r.S.cz)/(2.m)
**="power of"
r=volumic mass of air
S=aerodynamic surface
cz=vertical aerodynamic coefficient
m=mass
g=gravity acceleration

The solution of this equation is (velocity):
v(t)=sqrt(g/k).tanh(sqrt(k.g).t)
with
sqrt="square root"
tanh="hyperbolic tangent"

Terminal velocity: V=sqrt(g/k)

The integration is (altitude):
z(t)=1/k.ln(exp(1 sqrt(k.g).t)**2)/2)-sqrt(g/k).t
ln="logarithm"
exp="exponential"

r=:
- 1.225kg/m3 at sea level
- 1.057kg/m3 at 5000ft
- 0.653kg/m3 at 20000ft
- 0.551kg/m3 at 25000ft

g=9.81m/s2

The product S.cx is between 0.4->0.6, and can be greater with a wingsuit. S increase proportionally to the wing surface. cz variation depends on the wing shape but obviously slightly increase (ask the manufacturers!).

That's all for the scope of the BaseBoard.

If you need more details/informations, the BaseBoard is not the right place nor the right media. I'll email you if you request it.

[guest]

I made a mistake in the z(t) formula (text editor is not the right tool for formula writing). The altitude formula is:
z(t)=1/k.ln((1 (exp(sqrt(k.g).t))**2)/2)-sqrt(g/k).t

If you take k=0.00378 (approximately) (unit is 1/m), this formula gives the same results you can find in the Tools section of the BaseBoard.

[guest]

people like you piss off the realist's of this beautiful planet- stop bitching like a bitch-you probably are!!!!!!!!!!
simon's experience is not the question so ##### off and get yourself a gun, be shaw and put a bullet in it dickhead and have the balls to put a name to your #####
simon jump the cliff and look in free fall, it works for me!!!!!!!!!!
doesn't matter mate if your going to hit something you deploy your ???????????????????????
go hard and take chances, it's that how the sport began!!!!!!!!!!!!!!!!!!!!!!

[web]

i think i can do it with a 12-channel GPS, 100m clear 6mm teflon hose, a bottle or two of red wine, a rock and string, and a marine sextant to measure the angle between horizontal and line-of-sight to the exit point. know the Lat/Long of exit and observation points, and the rest is just geometry. anyone care to help develop this? i need someone to hold the other end of the hose.