platypii

Chart attached with all speeds: total, groundspeed, fallrate. Plus glide and l/d. Accuracy on this track seems okay. Jump is sensitive, so can't share the data, but will see if I can find a similar one that I can. BASEline - Wingsuit Flight Computer

Fair enough, you're right that with changes in airspeed and angle of attack, the L/D will also change. I glossed over this a little, but also tried to acknowledge it when I pointed out the variation in L/D in a typical glider polar curve. The L/D will change throughout a flight, but not by very much actually. It will change by moving along the wingsuit's characteristic polar curve. The l/d won't swing between wildly between 2:1 and 5:1 like the glide ratio does. Here is a chart of the "sustained speed polar" which uses the wingsuit equations to compute "sustained" horizontal and vertical speeds. In theory this is roughly what would be measured by aerodynamic instruments like airspeed and glide angle on an aircraft. The purple line shows the sustained speeds from the same jump as above, and you can see they fall within a fairly narrow range. The green line is my attempt at ballpark estimating a wingsuit's polar curve. That's why I would expect the L/D to not vary by much throughout the flight. [inline polar.png] Big caveat: the wingsuit equations can re-orient and change the frame of reference of the measurements, but wind still throws off the results. BASEline - Wingsuit Flight Computer

It wasn't constant airspeed nor constant glide. The flight went through a few phases and angles of attack, but as much as possible, the same body configuration. The green line is groundspeed / fallrate, the purple line is L/D calculated based on wingsuit equations. Although, I guess technically it doesn't actually require yuri's "magic" kl or kd coefficients to calculate L/D. Just change coordinate system to be oriented along the velocity vector, subtract out gravity, and what remains are lift and drag forces. However the magic coefficients do lead to interesting results when it comes to modelling the effects of mass, surface area, altitude, etc. I'm still trying to wrap my head around sustained speeds. BASEline - Wingsuit Flight Computer

Maybe you missed the part where I followed up with real world experience? And also explained how one can test if experience lines up with theory? Jump from a cliff, where you nail the angle of attack, hold the same body configuration through the whole flight, and then flare for deployment. Hypothesis: once up to speed, your L/D should be roughly constant throughout the flight. Here is an example of such a flight. [inline ld.png] You can see the l/d (purple line) quickly goes up to approximately 3.0 glide ratio, improves slightly with a bit more speed (typical of glider polar curves), and stays roughly constant through the flare at the end before deployment. Contrast with the glide ratio (green line) which starts low and takes nearly 10s to reach 3:1. Then some speed is converted into glide and so it continues rising to above 5:1 glide. But the debt must be paid, and so the glide ratio drops off below 3:1 before the flare. The flare again brings the instantaneous glide above 5:1 before the canopy opens. Data supports the theory. 1 track, small sample size? Sure. But I've seen this pattern over and over again on baseline. And since it agrees with the theory, and the intuition, and the data, I'm not sure why you are so skeptical? It provides an additional, more aerodynamically interesting, measure of wingsuit flight. BASEline - Wingsuit Flight Computer

http://www.pureflyingmagic.com/Content/Knowledge/Resources/Articles/en/WingsuitEquations.pdf You don't need physical data to prove it. If you accept the underlying physical equations: F=ma and lift equation, and if there are no mistakes in the proof (I don't see any, but onus is on you to find one), then the equations are valid. That being said, I've played with them, and applied them to real world gps data, independently of yuri's software, and they appear to match observed reality. For example with wingsuit starts... using WS equations you can observe the L/D being close to 3:1 throughout the whole start arc, whereas the GPS glide ratio varies wildly and takes much longer to reach "steady state". This is what I would expect to see from a true L/D measurement. BASEline - Wingsuit Flight Computer

Poll to see where people think we are, and where we're going with wingsuit performance. Not talking about with a flare, or with a tail wind. L/D BASEline - Wingsuit Flight Computer

No phone mirroring on google glass. It runs a weird variant of android 4.4 that google forked just for glass. I was able to make BASEline run on it, but it was definitely annoying. BASEline - Wingsuit Flight Computer

Yuri, I'm totally with you on taking a more scientific approach to wingsuiting, but your approach is probably not helping your cause. Anyway, what are your concrete suggestions to WS manufacturers? If you had a factory for a day what would you build? Proper aerodynamic instrumentation would be great, because GPS is useless when comparing between different skydives. But does it offer anything over flying next to someone? My understanding is that WS manufacturers do iterative development by flying next to people they fly with all the time, and see what effects are of suit changes. By flying relative to another person, the wind effects are irrelevant, and you can see if you can edge ahead of them, or out float them. Based on your models, do you think we should be working more on increasing lift (surface area)? Or more work on decreasing drag? How do the wingsuit equations help inform which changes to try? BASEline - Wingsuit Flight Computer

Disagree. Performance comps are all about the setup dive and energy management (aka- long slow flare). Also really hard to say with any certainty the effect of the winds. Based on all the data I've seen, and I've seen a lot, I think wingsuits are BARELY above 3:1 L/D. BASEline - Wingsuit Flight Computer

Google Glass on ebay is around $400 used. Not "cheap" but skydivers happily pay same price for an N3. Glass fits well under a G3 and runs android. [inline glass.jpg] BASEline - Wingsuit Flight Computer

It feels like manufacturers have been working harder on reducing drag than increasing lift. New ram air inlet designs are reducing drag while maintaining internal pressure. The swallow tail suit from Tony is a super interesting example of reducing drag... Most of the lift on any wing comes from the leading edge, so why not eliminate draggy tail? Other than... A lot of good work on refining the balance of the suits to make them easier/safer to fly. The relative location of the center of lift vs center of gravity can have a huge affect on the aerodynamic stability of a suit. Rbaseg has some interesting experimental suits that extend the wing past the hands. Seems like that's the only way to really increase lift substantially. [inline fliktail.jpg] [inline batsuit.jpg] BASEline - Wingsuit Flight Computer

Ahem... https://baseline.ws Also honorable mention to https://www.facebook.com/IcarusAngelo/ That being said, I completely agree your other points... wingsuit design and technology has SO much more potential. It's sad that we haven't even gotten 4:1 yet. BASEline - Wingsuit Flight Computer

Phone GPS is not great. It's almost always 1hz which is not ideal. But the bigger problem with phone-based GPS is where do you mount it? Anywhere in a pocket has a blocked view of the sky, and usually loses signal. I am the author of BASEline Flight Computer app and I highly recommend using a bluetooth GPS unit mounted on your helmet. This sends the GPS signal wirelessly to your phone. XGPS160 is the best I've found. The app has a way nicer interface than FlySight. You can change audible modes (speed, glide, etc) in the field. The app detects landing and uploads to the cloud automatically, so you don't need to mess with downloading your tracks later. PS- The XGPS160 is cheaper than FlySight on amazon [inline xgps160.jpg] [inline protec.jpg] BASEline - Wingsuit Flight Computer

Super cool project! For a heads up display, Google Glass works pretty well if you can broadcast the data over bluetooth. If you're interested in collaborating, it looks like you are well qualified to do the hardware side of things, I'd be happy to help out with the software side. I've basically already built the interface, but with only GPS data. Would LOVE to also have access to IAS. [inline glass.jpg] BASEline - Wingsuit Flight Computer

How about something like this? A paraglider that flaps like a bird: [inline paraglider2sm.gif] Human energy output is still a problem, but I think this would be closer. BASEline - Wingsuit Flight Computer

Then why aren't we seeing much carnage? Maybe the analogy doesn't hold. BASEline - Wingsuit Flight Computer

Have you considered the cost savings with using Hydrogen instead of Helium? Cheaper gas, more lift, smaller balloon needed. No smoking allowed though. BASEline - Wingsuit Flight Computer

Will ask a slightly different question: Will you learn more by doing solos on a small suit, or flying with people in a big suit? At many dropzones I've been to, that's the choice. I feel like I've learned WAY more since upgrading to the Freak because I can jump with other people who are better than me, more often. I get more out of each jump than I did doing mostly solos on my Swift. Another question: what is the downside to going bigger? Yes, there is more material to manage, and there is more risk of things like a flat spin, or deployment issues. But if you have enough experience on a small suit to fly out of instability, then I don't really see any down side to using a bigger suit. Really, the point of even wearing a wingsuit is to increase our flight performance envelope. Bigger suits increase that by more. So once it is safe to do so, why WOULDN'T you want to upsize? BASEline - Wingsuit Flight Computer

GPS is generally more accurate horizontally than vertically. This is because, for the most part, the satellites are not directly above, they are more off on the horizon, and so it is harder to get accurate vertical position. However, the FlySight actually has an advantage when it comes to fall rate: it can use doppler shift to measure velocity, which can be far more accurate than trying to compute velocity from position. That being said, I've studied a lot about barometric altitude vs GPS altitude, and looked at a LOT of data. When GPS has a good lock, and comes from a high sample rate, it is usually better. But sometimes it goes wildly off the charts, or fails to update altitude information for a period of time. Barometric altitude has much more variation, and oscillation, based on local pressure differences. But the magnitude of the error is much smaller than the errors you can get from GPS. If I were setting up for a swoop, I'd feel much more confident going on barometric altitude than GPS. For analysis on the ground, if the data looks clean, I would stick with the GPS data. BASEline - Wingsuit Flight Computer

Precision... having the walls helps as a point of reference. Repetition... how fast you learn something is strongly correlated with how rapidly you can perform the task, debrief, and go back and do it again. Consistency... there is no wind or other random air currents, so it's much easier to objectively evaluate your performance. For training... you could have them steadily increase the airspeed in the tunnel, and you need to learn to fly faster to keep up. Weather... not everyone lives in SoCal Look at how much progression in freeflying is thanks to tunnels. I'm hopeful that there will be a similar benefit from wingsuit tunnels. BASEline - Wingsuit Flight Computer

Video: https://www.facebook.com/926016670864446/videos/929883083811138/ Website: https://flywingsuit.se/en/the-plant-lt1-future/ Exciting times we're living in! BASEline - Wingsuit Flight Computer

Shameless self promotion: BASEline Flight Computer BASEline is an android app I made primarily aimed at improving wingsuit flight performance. It can: 1) Record sensor data from your phone including GPS, altimeter, and accellerometer data to a CSV file. The data can be analyzed later on https://base-line.ws/ 2) Provide real time flight data by speaking your glide ratio, horizontal or vertical speed. 3) Display your position, altitude and speed to give you real-time visual flight data. Getting good data is tough with a cellphone though. If you are going to use a phone instead of a flysight I strongly recommend using an external bluetooth GPS unit. See here for more details. BASEline - Wingsuit Flight Computer

Wow. Squirrel wouldn't give you free money AND wouldn't let you cut the line!? It can be hard to believe how entitled some people are. BASEline - Wingsuit Flight Computer

It depends what your goal is: flocking vs terrain flying. If you are just trying to flock with other skydivers, then you will not be flying at maximum performance, and so as long as you can match speed and glide with your fellow jumpers it doesn't matter too much how. Others might be able to give tips on body position that might help with stability or precision, but whatever works for you is fine. If you're planning to terrain fly, speed is by far your biggest asset, and flying with your arms swept back is slower than diving with your whole upper body. Keep your wings mostly level and angle down at the hips / shoulders / neck. "Strong Arm Technique" Video: https://www.facebook.com/scottybobws/posts/10154237601399474 Discussion: http://www.basejumper.com/cgi-bin/forum/gforum.cgi?post=2987558#2987558 BASEline - Wingsuit Flight Computer