www.ka72.com/ was updated last night to add a few new things.

1) Improved Alpha calculations and spike detection. Some results that were marginal before are now being calculated more accurately. (Details below for the boffins.)
2) Results page now indicates whether results are trackpoints or doppler
3) Beta integration with GPSTC, post your results straight from ka72.com (this will eventually be a members-only function, but during the beta period it will be available for everyone to use. I'll post back here in the future with plenty of notice if I'm taking the functionality off the public site.)
4) Extended lists of recognised firmware revisions

Please let me know if you find any issues with the site (dylan@ka72.com), or anomolies with calculations. Thanks to everyone who sent me bad/unusual files recently to test with! Now working on location auto-recognition.

Technical Details:
Previously, ka72.com used linear acceleration to filter out spikes. If you went from travelling at 20kts to 70kts and back to 20kts again, it was fairly certain that there was a spike, and it was filtered out. However, many spikes involve sharp changes in direction, not necessarily changes in speed, so linear acceleration is useless in filtering out these spikes. Due to this, sometimes bad measures were being reported by ka72, especially on Alphas and 5x10.

With this release of the ka72 engine, calculations of acceleration take the direction of travel into account. This means that if your track corners sharply, faster than should be humanly possible, then it will be filtered out as a spike.

Obviously there was a risk that this filtering would be too great, and accidentally filter out actual really sharp turns. Some of the past months' work has involved fine-tuning the parameters and running thousands of automated tests to ensure that this isn't the case. I think the site is very well tuned now, but if you can throw in a file that you know has a known good gybe, and ka72 filters it out, or vice versa, please let me know and I'll revisit the tuning.

Thanks everyone, looking forward to Burrum!

Dylan.

A big round of thanks to Dylan for setting up KA72.com and developing the software. We use it in the US for the HAM Challenge and it guarantees everyone uses the same software for consistent results. Can't wait for the location auto-recognition, it will make a great system even better.

Many thanks for all you hard work Dylan.

Great work Dylan - well beyond my level of understanding but looking forward to the auto upload to GPSTC.

See you in a couple weeks at Burrum.....don't forget to wear your cowboy suit so people who haven't yet met can recognise you.

PS - you should try to get an alpha track from Jaques van de Hout (JP / NP +46knot Club Netherlands) to test. I think he has a 29knot alpha.

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sausage said...
don't forget to wear your cowboy suit so people who haven't yet met can recognise you.

Hmm. Remembering the last time I wore a cowboy suit, you probably don't want to see that. (That was an interesting night...[}:)])

Thankfully most of the windsurfers who were there are now kitesurfers or ballroom dancers, so out of the loop one way or another. Now I just have to locate and destroy the final few photos.

Dylan.

Just used the updated site.
KA72.com is now even better and easier to use.
The direct link to post on the GPSTC is very convenient.

Great work Dylan.

I recently bought a GT-31 and trying to do alll the download tech stuff.[}:)][}:)][}:)][}:)][}:)][}:)]

I am not really up with the Talk or computer terminology that goes with it.!!!!![}:)][}:)][}:)]

DYLAN!!!
i will obviously need to talk to you as you seem to be the only person instructions I can follow mostly - spare some time for me at Burrum Heads PLEASE !!!!!

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goldcoastmoz said...

I recently bought a GT-31 and trying to do alll the download tech stuff.[}:)][}:)][}:)][}:)][}:)][}:)]

I am not really up with the Talk or computer terminology that goes with it.!!!!![}:)][}:)][}:)]

DYLAN!!!
i will obviously need to talk to you as you seem to be the only person instructions I can follow mostly - spare some time for me at Burrum Heads PLEASE !!!!!

Moz,
I told you to bring it in on Saturday. Thinking you'll go faster if Dylan sets it up, hey.

Never got a chance to come down Saturday !!!!

But as you said - Dylan is the best!!!

(Dylan posting via Kellie's account.)

KA72 HQ will be Whispering Palms (about 50m from Burrum Sands, on the corner of Burrum Pde and Torbonlea St.)

I'll be there from Thursday, and I encourage everyone to drop by at least to check that your Navi is set up right before the event.



Also taking the Wii for rainy-day play and after-hours relaxation.