Gorgo said...
Yeah. I just past my mate. If I am looking down on his kite then I am fricking high!

The other fun way to gauge height is to do a long, high jump ... then watch all the windsurfers riding under your arc. My best is a three windsurfer jump.

Gorgo - how many times do i have to tell you,
Looking down at your mates kite while in its backpak doesnt count lol
And a running jump over 3 poley boards in the setup area - arc or no arc... means back to Re-hab ha ha

Hmmm I happen to have a fully robotic tracking Total Station, Leica TS15, which will follow a target automatically. It locks onto the target and follows same and can automatically record data including heights, every second or so. Normally we use "survey" targets but it will measure to reflective tape. Our normal survey prism targets cost $100's therefore not willing to possibly sacrifice them.
Lambie, come on over for a test jump.

Cool.

Mark _australia said..

Completely separate from your kite at the apex of your jump, and freefall to the water.
Time it with a stopwatch

9.8m/s/s

There u have it.

Ah, the old 9.8m/s/s... that takes me back to my physics lessons... Thanks for trip down memory lane!

SaltySinus said..

Mark _australia said..

Completely separate from your kite at the apex of your jump, and freefall to the water.
Time it with a stopwatch

9.8m/s/s

There u have it.

Ah, the old 9.8m/s/s... that takes me back to my physics lessons... Thanks for trip down memory lane!

Joking aside, the scary part is that many expensive products use this "free fall" method in an attempt to give jump height. Using this method is literally impossible to give consistent heights, and is there is an off axis G (spin, etc) then the system will never "see" the jump. Also, if you take a look at the Xensr kite tests from my earlier post, you'll notice that the single shot jump, the rider kite loops on the descent to keep from splattering on the water - this is seen as a "landing" by systems like ***** and ********* but Xensr "sees" the whole jump as is.

We track the jump through our sensor fusion - we're taking input from five different sensors at over 400 samples per second to accurately track the actual 3D path of the rider (or wherever its mounted) and we identify jump events in realtime. As soon as you land, we know your height. It doesn't matter if its a flat surface jump in kiting, a drop in skiing or a tabletop jump in mountain bike. You can spin, flip, etc. as hard as you like (we track that as well) and we'll always see your jump. ;-)

nugs said..

Sounds like a winner. Question though.... what type of sensors does it use? Do they work in the dark and more importantly are they accurate in the dark or poor lighting?

I have an idea. Build this type of technology into a camera silimar to GoPro. Better yet, add GPS for linear tracking aswell.

Imagine a GoPro that can also map out your tricks in 3D on computer and track your geographical movements.

The XensrCase uses accel, gyros, magnetometer, GPS, barometric (though this is NOT used for jump heights) all mixed together to give our smooth 3D TruMotion tracking data. Works just fine in the dark, jumping out of an aircraft, mountain biking, skiing, base jumping, etc. ;-)

The problem with GoPro's/POV cams is that camera location usually is NOT the desired place for data collection for boardsports.

You can export your data into your POV of offboard video like we did in the demo videos, but the actual product results are better than the test graphics you saw there.

LostDog said..


All sounds and looks cool... now to get a heart rate monitor attached to see how much one's HR goes up vs height of jump.

If you are using a BT4.0 heart rate monitor, we support that in the app, so yes - you can monitor your heart rate during your
sessions as well as the other data. ;-)

So when do you expect these to be available, and how much?

Hey that looks like a fun little gadjet - this is how they measure Height...

Quote: How are jump heights measured and how precise is it?

The XensrCase is looking at your motion 400 times every second. It?s examining your G loading (acceleration) in all 3 axis, your angles (gyro), keeping track of where the Earth is (GPS + magnetometer) and watching the air pressure. All of this data is used to determine your precise 3D location, and also watch for jump events.

Many assume that Xensr?s TruMotion? technology uses the altimeter for jump heights ? this is incorrect.

Xensr computes your jumps based on movement data ? for water sports, the XensrCase is sealed against water in an airtight case, thus preventing any reliable air pressure changes to be measured rendering the altimeter useless. The 3D measurement from TruMotion? gives jump height data to less than one inch of precision. Sometimes it?s as precise at 3mm and averages around 1cm of precision. At worst, it?s 1 inch of precision, so that?s what we use for our precision claim.

Having read the above - Does the Xensr have 'Official' approval as a speed / height recording device for World competition...

What is the warranty on it and what is it Impact rated at for obvious mega jump crashes ???

We all know the "Shadow box" was a 'Pre order failure' with software problems and months late for delivery - Once bitten twice shy in Australia !!!!