audible "time-out" for BASE

[guest]

Several people have posted about how enjoyable they find jumping in/through fog. If an inexpensive gadget allows it to be done more safely, then why not? After all, many, if not most, mornings with ideal wind conditions for BASE happen to be foggy. It is almost unavoidable.

Again, the device would beep once per second during the freefall, so the user would have ongoing confirmation that it is indeed working, and the user can count along so as to anticipate deployment time. Or it could have a warning tone a couple seconds prior to the deployment tone so you could take a second to react-reach-and pull.

[Derek_The_Freak]

I had a similar idea, but I was thinking more along the lines of using the same concept of how modern AAD's work in combination with a dytter. It would basically be a "SENSATIVE" digital dytter. Once triggered (once device knows the jumper has jumped) it could be programmed to start beeping after X (user settable) seconds and/or at a certain alt (again user settable).

Like in skydiving, it would be meant to be a passive device, but like in Lees case where changing weather and fog levels impaired his perception it could make all the difference.

The problems I am having is:
1) Its useless on short/medium delay where you toss almost immediatly... But in that case accuracy counting to 3 isnt an issue. It would be best suited for medium to long delays.

2) I say it has to be "sensative" because dytters/AAD/altis use barometic pressure as a means to determine alt/rate of fall. But it isnt even close to 100 accurate. The same would be true for BASE applications, winds, turbulance, air pockets could all throw it off. So it would have to be programmed VERY wisely (a huge challenge in my opinion). It would need to use barometric pressure, and rate of descent to calc. when to alert the user. It would have to interpolate the curves (between rate of descent and barometric pressure) to determine when to alert (using the safer of the 2).

3) It would have to have an EXTREMELY accurate means of determing when the user jumped. Obviously if it doesnt work right, then it may give erraneous readings. I have a few ideas of how to do this...

3) The user. thats where the resposibility lies...

So what do you all think. Derek

Ohh yeah constructive critisicm is gladly accepted. Practice safe whatever ;-) Derek :-)

[guest]

I intentionally veered away from a pressure-based system due to all that complexity and the need for acurracy within 100 feet or so. I don't think a pressure based system could do it. Also consider that a pro-dytter re-zeroes itself periodically every few minutes on the ground to compensate for weather changes. Your system would have to be manually zeroed on the ground and then would rely on the weather NOT changing by a +/- 100 foot (equivalent) in the hour it takes to climb the tower.

A timer-based system should be somewhat repeatable given the fact that the acceleration of gravity is controlling for the fist several seconds when all the aerials are going on (if applicable). Once drag becomes controlling, variability is introduced since the jumper may be tracking or wingsuiting it, or falling in a boxman. The user would have to determine what delay (in seconds) is appropriate to their planned fall rate, and adjust from tabulated time vs. distance tables, as needed.

[Derek_The_Freak]

just an idea. I think it is viable, but would have to be approached very wisely. if you really want to get accurate, you could use accelerometers. ;) they use them to guide long distance missles (without outside guidance) over ranges of 1000s of miles while being very accurate. How big is a a couple of 3ring laser gyros anyways. hehehe
J/k
Derek

[crwper]

Laser gyros sell for tens or hundreds of thousands of dollars -- they are precision instruments. You can get piezo gyros for less than a hundred bucks US, and they're fairly accurate, but they can't handle sudden changes in attitude.

Inertial navigation systems, with 3 gyros and 3 accelerometers that would be appropriate for the BASE environment, sell for about $10,000 US, and are rather bulky.

But maybe you don't really need a gyro if you just use 3 accelerometers and a bit of intelligence in your measurement.

You'll want to find a cheap way to distinguish between acceleration due to gravity, and acceleration due to the launch, other than gyros probably.

Woodpile had an interesting idea -- triggering the device when the acceleration drops below a certain threshold. The acceleration shouldn't drop until after your launch, so you can start integrating then.

If the user is accelerating horizontally (ie tracking), I believe the device will think it's falling slower than it really is (because it will measure an acceleration which it assumes is caused by air resistance), which could be a problem.

I think if you're going to use a gadget of some sort, maybe you should use a simple one -- maybe a simple timer like Woodpile suggests. The idea is relatively foolproof, at least as far as the accuracy of the device, which leaves all the dumb-ass mistakes up to the user.

Michael

[460]

yeah i think accelerometers are the way to go instead of mercury switches. I just found some inexpensive ones that are very small with an accuracy of +- 0.001g. I think I'll order some and build something that accomplishes the intended goal of timing alert after exit. -Chris

[guest]

If anyone ends up making this device,please post it on the board.I would be a test jumper for it.

[Derek_The_Freak]

I know, i was being 1/3d ass, 1/3d sarcastic, and 1/3d half serious.

Sorry - long day. I know accelerometers are expensive. ;) and big.

I think the timer is a good idea tho, I just like the added feature of actual alt sensing. I think it is soemthing that needs lots of thought, lots of testing, more planning, etc. Derek

[crispy]

>How about a fog layer coupled with changing
>weather conditions associated with Skypunk's
>accident? What good is depth perception going
>to do you under those circumstances?

I'll defer to my good judgement in that case and go shag my girlfriend earlier rather than later.

[guest]

COUNT Seconds? you gotta be fu(king kidding....

[pringles]

I think this could be a good idea. What if this device was just some sort of timer that would beep once every second... Or what ever the user would set it to. You could just press a button on it when you are ready and maybe it could even give you your count down three two one c-ya. At that point you would jump and it would start its beep every sec. Or like with the new cell phones, it could be voice activated. You could program it to your count down and then it would start. I think that it would just need to be a simple idea. None of this barometric pressure crap. Just make it simple.

Just my 2 cents
Matt
bsbd

[jupija]

i have a device something like that my self (home made) that after i turn the switch on when i m ready to jump it starts counting seconds (like: 3,2,1 jump 1-16 sec.), but i didnt test it jet. I just monted it on my back hand. My question - if anyone is using such a equipment what is whit the noise from the wind when u start to gain some speed - can u still hear anything?

why dive if u can skydive:D

[Tokemon]

yeah, accuracy down to 100 or so feet. maybe I should be using my skydsiving altiimeter when I climb my 225 footer to see if the needle moves. what will an altimeter that reads within 100 feet so for me? When I'm at top, I would set it for 100 feet. then, when it zero, at 100 feet, it means I better hae thrown the pilot chute. BETTER HAVE THROWN IT.
audible altimeter. heh, I got one of those too. works great at perrine. jump, and wait til you hear wind. then pitch. it yields some pretty fun, scary looking openings.
that, and I like to use lights on towers. I usually pull by third light. allowing one light to open. unless tower is only two lights. see above afformentioned.
non-irregardlessly thereto jump whatever kind of gadgets use please. I'm still trying to figure out a way to spark one in freefall. with a 6-8 second delay, I should get one hit at least. heh eheh hee hehe heh eh eh eheh eh eh cough cough!!
later,
Thomas :-) :-) :-) :-) :-) :-) :-) :-) :-)

[Tokemon]

so, I just got an idea about flames in freefall. If I pull one or two slow somewhat tucked front flips, I may be able to create a nice burble inside!!!!
heh heh heh
Thomas :-) :-) :-) :-) :-) :-) :-) :-)

[guest]

Do we really need electronic stuff for BASE ?

Ask AirTec for a laser-distance-to-ground-GPS-assisted-Cypres with 5 different alti warnings......

base chicken