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Katscan

Hello World!!

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Greetings,

I just wanted to introduce myself. I've been lurking around these forums for about half a year and just finished my AFF.

Since the skydiving community has given me so much in helping me finish my AFF, I felt that I had to try and contribute by registering and posting to this forum. Don't worry I also contributed to my dropzone by loading off 48 bottles of beer after I finished.

I have learned much from my instructors and also by reading the posts of all you experienced skydivers. I hope to learn more and be part of this great community.

Blue Skies!!!

PS: Any suggestions on gear stores in Nor Cal where I might be able to try on helmets before I buy?

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Ooh, you might be interested in some of my C++ libraries up on Github, then. The gpx2kml one is designed to take a GPX data file from the android "Mytracks" program and convert it into a KML file suitable for display on Google Earth. It has some rudimentary support to analyze a jump and detect canopy deployment. It's still pretty rough -- I find the exit point in the GPX file manually and trim the data down. Eventually I want it to pull the jumps out automatically, but I haven't got around to writing that bit yet. Always too busy jumping out of airplanes during prime weekend programming time!

I've found my Android phone is EXTREMELY unreliable as far as GPS coordinates go. One of these days I'm probably going to have to break down and buy a flysight and write a factory for its data format. Still, I've gotten some halfway decent tracks from it, which look freaking awesome on Google Earth :)
https://github.com/FlyingRhenquest?tab=repositories

I'm trying to teach myself how to set things on fire with my mind. Hey... is it hot in here?

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If there are some jumpers at your DZ that have what you are thinking about, go ahead and ask to try it on. Most don't have a problem with it - but start with questions about their helmet first. They may even offer.

Heck, I've even let a couple people jump mine if they were actually serious about it... However, they did seem like they showered that day ;)


Once the plane takes off, you're gonna have to land - Might as well jump out!!

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FlyingRhenquest

Ooh, you might be interested in some of my C++ libraries up on Github, then. The gpx2kml one is designed to take a GPX data file from the android "Mytracks" program and convert it into a KML file suitable for display on Google Earth. It has some rudimentary support to analyze a jump and detect canopy deployment. It's still pretty rough -- I find the exit point in the GPX file manually and trim the data down. Eventually I want it to pull the jumps out automatically, but I haven't got around to writing that bit yet. Always too busy jumping out of airplanes during prime weekend programming time!

I've found my Android phone is EXTREMELY unreliable as far as GPS coordinates go. One of these days I'm probably going to have to break down and buy a flysight and write a factory for its data format. Still, I've gotten some halfway decent tracks from it, which look freaking awesome on Google Earth :)
https://github.com/FlyingRhenquest?tab=repositories



WOW, that is brilliant. I only took a quick glance, but that is very cool use of the data. I personally would be too afraid to jump with my cellphone just because I'm new and PLFing 1/3 of my jumps...

The problems with reliability of the GPS I'm guessing are caused by the polling rate and general signal loss (probably not something you can control). Also moving as fast as you are when skydiving probably doesn't help... haha.

Bookmarking this to really go through it when I have time.

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TEB6363

If there are some jumpers at your DZ that have what you are thinking about, go ahead and ask to try it on. Most don't have a problem with it - but start with questions about their helmet first. They may even offer.

Heck, I've even let a couple people jump mine if they were actually serious about it... However, they did seem like they showered that day ;)



Thanks for the heads up. I've started doing this recently. Everyone has been very friendly about letting me check out their helmets and some have let me try them on! I know some people are very sensitive about hygiene though, so I'm never pushy about trying them on.

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Katscan


WOW, that is brilliant. I only took a quick glance, but that is very cool use of the data. I personally would be too afraid to jump with my cellphone just because I'm new and PLFing 1/3 of my jumps...

The problems with reliability of the GPS I'm guessing are caused by the polling rate and general signal loss (probably not something you can control). Also moving as fast as you are when skydiving probably doesn't help... haha.

Bookmarking this to really go through it when I have time.



There are a number of potential issues with GPS data really. Above a certain altitude and speed the GPS is not supposed to function (Ones that do are regulated as munitions.) However, I'm always well below the altitude and speed. I forget the exact numbers but I think it's over 30-40K and faster than 300-400 mph.

It's just the cheap GPS in the phone. There are decently high precision models you can get that would probably be accurate enough to give you decent logs for your entire jump. I'm pretty sure the Flysight would, and I'll probably end up buying one when the wingsuit comes in, anyway.

It's easy enough to add a new file format -- you just need to implement a new factory for it. Once I add another, I'll probably set up a proxy object that just forwards the file to all the real factories and forwards their coordinate notifications on to any listeners. All the rest of the code would remain the same.

I'm planning to use a similar idiom to parse jumps out of files with multiple jumps -- design a "skydive" object with interesting data in it and create a factory class to build them. That'd make it easy to isolate the strategies I want to consider to isolate the different parts of the jumps. Converting to ECEF and using a criteria of "The first point after the jump starts that's less than 10 meters from the previous point" seems to be doing a wonderful job of detecting canopy deployment.

The gpx2kml.cpp file is kind of jumbled at the moment as there's a lot of code in there I was using to explore the difficulties involved in doing something like this. Once I clean it up a bit, there should be almost nothing other than option handling in that file.
I'm trying to teach myself how to set things on fire with my mind. Hey... is it hot in here?

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