• Content

  • Joined

  • Last visited

  • Feedback


Community Reputation

12 Neutral

1 Follower


  • Container Other
  • Main Canopy Size
  • Main Canopy Other
  • Reserve Canopy Size
  • AAD
    Cypres 2

Jump Profile

  • Home DZ
  • License
  • Licensing Organization
  • Number of Jumps
  • Years in Sport
  • First Choice Discipline
    BASE Jumping
  • Second Choice Discipline
    Wing Suit Flying
  • Freefall Photographer

Ratings and Rigging

  • USPA Coach
  • Pro Rating
  • Wingsuit Instructor

Recent Profile Visitors

762 profile views
  1. The key to the biggest flares is 1) building up a lot of total speed, and 2) efficiently converting that into a flare. This is an example of a huge flare with 314ft of altitude gain: I think it's most useful to look at the speed polar: What this shows is (1) building up a huge amount of speed by diving aggressively. (2) continuing to dive but increasing the horizontal component of velocity. (3) as smoothly as possible exchange airspeed for lift. (3) begin going up. (4) maximum upward velocity 45 mph. (5) top of the flare, when vertical velocity hits zero. If you flare too hard, or if you break it up into "phases" between 2/3/4, you will lose more energy and not gain as much altitude. Also if you flare too gradually, you will bleed off speed due to drag and not gain as much altitude. It's a balance. Interestingly on this track, (2) has more total speed than (1). I actually think it should be more efficient to not go quite as vertical as that jump, and short cut the transition from 1 to 2. The main thing is to maximize total speed before the flare, but if you can do the same total speed at 1:1 glide as when vertical, then you're in a better position to start the flare.
  2. Or maybe you don't understand standard deviations. If a sky canopy opens in 500ft +/- 500ft, but a BASE canopy opens in 200ft +/- 100ft even at terminal... then no, there is virtually no difference in risk pulling at 2000ft or 500ft with a BASE rig. You might have a little more time to fix a malfunction, but the difference in risk is pretty minor in my opinion.
  3. Applied Wingsuit Equations: Reconstructed roll angle from GPS data, overlayed on terrain. @yuri_base
  4. When I said "satellites are mostly near the horizon" I meant that statistically at any given time, you are more likely to have satellites off to the side, than overhead. And If you're trying to use triangulation to measure height and vertical speed... that's going to be less accurate without satellites overhead. Geometrically it's a fact that they are more likely to be near the horizon than overhead. Here's why. If you draw a line extending out 45 degrees above the horizon, then the area of sky "above" you is much smaller than the area to the sides. I get a ratio of more than 2:1 "near the horizon" vs "above" at GPS altitudes. Picture is drawn to scale. I will say though, I expected a bigger ratio. But because GPS orbits are actually quite high, this is less of a factor than if they were in lower orbit.
  5. GPS units generally have a physics model of what is "realistic" speeds and accelerations. These are used in kalman filters to clean up noisy GPS data. It probably thinks that falling at 120mph is not realistic. Also the satellites are mostly near the horizon, so GPS is inherently less accurate on altitude than position. And finally -- check where it's mounted on your body. If its chest-mounted, you're going to be blocking its view of most of sky. Do you backfly? Cool project!
  6. He's wearing a BASE rig, so no, he doesn't need emergency handles :-)
  7. The 3-ring wikipedia article is surprisingly detailed, with a nice animation of the mechanism:
  8. Just released a new version of BASEline tonight that will scale text with the android system font size. Thanks for the feedback. Keep us posted on your project!
  9. I've done this using Google Glass and it works well. I'm the developer of BASEline Flight Computer, so it was fairly easy to port the Android app to Google Glass. You can find used Glass on ebay for around $400. As you mentioned, the advantage of a HUD is that you can see horizontal speed, vertical speed, total speed, and glide ratio all at once, and with much faster update than you could ever get with audio. I personally chose to display your speed as a "polar chart". Horizontal and vertical speeds on the axes, total speed equals the hypotenuse, and glide is shown by the slope: To get good data, pair the phone with a bluetooth GPS like the XGPS160. Let me know if I can help with anything. I would love for this to exist! But I don't expect most people to deal with google glass. If interested, the google glass version of BASEline is available on a github branch:
  10. Computing velocity from noisy position data can introduce a fair amount of error. Here is an example. Your true velocity might be constant and actually look like: But GPS will have errors that might make the position look like any of the black dots here, and you can see how much error that can introduce to the velocity if computed using distance / time: It's possible to smooth this out by adding a Kalman Filter. But a filter will introduce its own errors and create a lag time before it accurately estimates your true velocity. However, as pointed out by @crwper, GPS actually has the ability to compute position directly, not using position and distance. Instead, many GPS chips can actually use doppler shift from the satellites to directly compute velocity. The accuracy and response time is much better. It is not clear whether the GoPro uses doppler velocity to compute 2D and 3D speed, but its definitely NOT giving the individual velocity components (vN, vE, vD) which would be nice to have.
  11. Actually I find the touch screen to be one of the biggest selling points of Dekunu over the X2. I own both and I HATE using the 3 button interface on the X2. Using the touch screen is so much more intuitive, way easier to find things in the menu, easier to use while on the ride to altitude, etc. On the topic of the screens, they are very different! The Dekunu has lit up screen (like a cellphone), whereas the X2 has a passive screen (more like a watch screen). Neither is strictly better than the other... X2 might be a bit better in direct sun, but overall I find it easier to read the dekunu in most cases. Dekunu has wider viewing angle, and usually its in the shade on my chest strap while wingsuiting, so the lit up screen it more readable. Plus the LCD screen on the X2 sometimes interferes with polarized sunglasses. Overall, I like the Dekunu more, but I am excited to see how both these units get upgraded over time.
  12. Overall really happy with the site redesign. Great work! One super minor request: it seems like with the new CMS, the favicon disappeared. I like to keep my favorite sites on my bookmarks bar with just icons and no text:
  13. Cool application of WSE: Roll Angle from GPS data! Basically, by finding the angle of the Lift vector relative to flight path, you can compute the roll angle of the suit. Here's an example of pitch, roll, and yaw reconstructed from FlySight data: This shows initial steep exit from a cliff, followed by leveling out, a slight right turn, a corkscrew (!), then a long commute before deploying. Note that the visualization assume AoA = 0. Credit to Hartman for the roll angle calc, and DFR for the corkscrew line. BASEline - Wingsuit Flight Computer
  14. I'm going to preface this by saying that I'm highly skeptical of this idea, especially since you haven't even addressed how deployment would work. But... You should check out "hot wire foam cutting". There are super cheap tools available on amazon so you can do manual sculpting of foam. There are automatic hot wire cutting machines that can make them. Also some clever DIY hacks to make it cheap. High end professional hot wire cutter with overly dramatic music Very relevant DIY foam cutting of an airfoil (very long video) BASEline - Wingsuit Flight Computer
  15. Yea working on an edit now, something looked wrong. In my defense, in baseline the formulas are implemented in 3D, and I had to re-do the math today for the 2D version. BASEline - Wingsuit Flight Computer