):
June 11th, 2002 Biil Dause at the Lodi, California DZ has held a tracking contest for many years. He could probably give you some figures, such as exit and pulling altitudes as well as the distance covered over the ground.
I have heard of some amazing non-suit distances being covered by jumpers with the right build and proper body position.
:o BASE359 :o
June 11th, 2002 Use a gps receiver to calculate distance traveled. Then compare it to distance fallen. that should give you a usable slope. I'm too drunk to explain how to use the GPS for this task, but your a smart guy so I'm sure you can fifure it out(Need figures like plane speed wind speed/direction, way points..etc). Takes just a little math. Also I modified a stop watch w/bite switch to measure time. Hope this points you in a somewhat usable direction.
June 11th, 2002
I have GPS data for myself, but I'm trying to get a wider range of data. I'd especially like to get data for wearing boosters versus freefly pants versus standard clothing versus ski pants.
I'm also interested in fall rate. I'm currently getting greater than 8 secs per 1000' or about 80mph vertical fall rate in a max track. I think this is about average for a reasonable track without high drag clothing.
I am interested in what the averages are and what the upper limits are as well (without extremes in high drag clothing).
June 11th, 2002 Yo !
While playing with GPS on wingsuit flights i have found out that it's surprisingly hard to get precise data - because of the wind. GPS will measure your ground speed, but what you are really interested in is the airspeed. Usually winds aloft will change in both strength and direction. Although some people think that going crosswind will give you an exact airspeed measurement, you are still adding almost half of the wind speed to your own. So the error margin is usually too big, and naturally people tend to err to their benefit ;-) Most tracking contests are going crosswind, so on an average day they are probably adding about 10mph to their true airspeed... which is a lot, when measuring L/D ratio.
I usually make a few 180 turns while flying a wingsuit and GPS to make a good average airspeed measurement, but this will be virtually impossible for a regular tracking dive, because of a limited working time.
Big cliffs offer a slightly more precise environment, but you still have to account for the acceleration phase. It is relatively short (about 6sec) for a wingsuit, but a regular track takes a bit longer to achive full speed...
So, why track without a suit ??? ;-) Seriously, the best trackers seem to push 0.9 L/D and 80mph vertical, but the vertical (and horizontal) speed depends on your weight - whlie L/D only depends on your shape.
bsbd!
Yuri.
June 11th, 2002 Yuri,
Don't you have GPS coordinates of the distance to the water from exit on Smellveggen. Douggs made it. Also the Norges are tracking like gods now. They now make it over the ledge in Karlskratind. I haven't been at the top yet but I heard that its far ! Whats the glide angle to get over that, even taking into account the acceleration altitude used.
The way I see it, god, nature, gaia, whoever, created some jumps for wingsuiters and some for trackers. Hårstadsnebba is a wingsuit jump for instance, while Kathammar is just made for tracking.
/Lukas
June 11th, 2002 I have been up on Karlskåtind. It is a big ledge :)
The wall is ~1350m (if I remember correctly) from exit to the meadow. A Norwegian female basejumper did over 30 sec and pulled far beyond the ledge and did not pull low.
I have seen people in wingsuits that pulls in the same place :)
Some of the Norwegians are monster trackers
PerFlare
Member Team Bautasten
http://www.linetwist.net
June 12th, 2002 I agree with Yuri that it is not so easy to get good and reliable data about Tracking efficiency (Hd/Vd, ratio Horizontal distance/Vertical distance) with GPS.
I have only (about) 3 skydives with GPS data logged, and surprisingly (for the time) I didn't get "stable" values for velocities (horizontal and vertical, and so as well for their ratio).
I explain better. Set in advance that I am NOT an incredibly good tracker, velocity data from GPS are very accurate, but (I discovered it later) only if the velocity itself is stable, constant, steady. When I drive my car and I drive at a fixed speed, the velocity is very stable in value and very accurate. Once (for whichever reason) you change velocity, GPS takes seconds to adjust itself to the right velocity (once I did a domestic flight and I turned my GPS on, surprisingly I got, yes, in the end the right value of aircraft velocity of about 900 km/h, but it took minutes (!!!) to get it steady, starting from 500 km/h range and slowly increasing up to its final value).
To make a long story short, data logged about my skydive tracks showed quite "dancing" numbers, even if I did quite a stable track, "dancing" numbers even in a range of track where velocity "should" have been stable.
In the end, I got my best (tracking) efficiency of 0.38, sorrounded by values as 0.35, 0.32, 0.34 etc etc. While (I guess) efficiency of tracking with wingsuit should be something around 2.0.
Anybody has got similar numbers? When I shall be back to skydive ( :-) ), I shall collect more data about efficiency of tracking.
Stay safe out there
Blue Skies and Soft Walls
BASE #689 :D
June 12th, 2002 people people talk to the tracking master fast al he can out track a rock ,douggs is sh! t next to our falling safe Al
bsbd feral
All piss intended!!!!!!!!!
:-( :-( :-( :-( :-( :-( :-(
June 12th, 2002 If you want to obtain reliable velocity information from GPS data, you'll have to take the position information (which is fairly reliable), and apply some kind of smoothing function. A window of a few seconds to either side works fine.
Michael
June 12th, 2002 Yeah, well, I bet 'ole Al tracks like a bird compared to my sorry, heavy ass. Man, I WISH I could track as well as Al :-(
Peace,
D-d0g
ddog@wrinko.com
www.wrinko.com
June 13th, 2002 >...you'll have to take the position information
> (which is fairly reliable), and apply some kind
> of smoothing function.
Michael,
How can you apply the "smoothing" function?
Is the "smoothing function" available with Oziexplorer? Oziexplorer is the software I have used so far for plotting (and collecting data) my tracks.
Still, I heard that the new version of Garmin Mapsource is capable of drawing the tri-dimensional plot of track, I haven't yet tried, though...
Stay safe out there
Blue Skies and Soft Walls
BASE #689 :D
June 13th, 2002 Sorry, the smoothing function is something I implemented in my own software. It's not currently very useful for wingsuit stuff (much more useful for seismic survey planning, if anyone out there is in the business), but I'm working on a new version right now, and when it's done I should be able to offer a free stripped-down version with some of the stuff everyone's looking for.
Michael
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