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Old September 24th 12, 06:09 AM posted to rec.aviation.soaring
Eric Greenwell[_4_]
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Default Gather local wind data

On 9/23/2012 7:43 PM, Steve Leonard wrote:
As Tony said, we can have really inacurate forecasts here. Mainly
because our closest sounding sites are either the other side of the
Marfa Dry Line, far enough upwind that even though there are no
obvious airmass boundaries, the airmass is definitely different (look
at OLC posts from Hinton, OK versus Sunflower on 7-20-2012), or far
downwind into the armpit of the soaring world (Topeka, KS). A local
sounding is really needed to know what might happen.

As for hiring an ultralight, that would probably cost at least as
much each time as a helium balloon. And remember. We are in Kansas.
The reason I was thinking of using kites is because the wind blows.
Lots. And many days, the ultralight pilot will either not be
available or willing to go. I have a couple of hundred dollars worth
of kites and high strength line. Now, I just need a small data
package to put onboard!

Those are neat loggers, but I didn't see one that measures pressure
(altitude). Without that, you have nothing. What we are really
looking for is "will it go to at least 3000?" The day's Tony
mentioned were 5000 MSL, or 3500 AGL. With a saounding to even 3000,
we would know what we would be up against.


Here's one that's not as convenient, perhaps, but does measure altitude
and temperature, plus GPS and more if you want it.

$70 logger
$38 20k altimeter sensor
$11 temperature sensor
http://www.eagletreesystems.com/MicroPower/micro.htm

The model rocket people have this kind of stuff, and a 3000 agl rocket
might be a cheap and reliable way to put the instruments up where you
want them. Retrieving in a wind would involve a chase, but they also
have locators of various types to help find it. There is likely a model
rocket society somewhere near you that could help.

Here is a rocket logger: altitude, temperature - $80

http://www.perfectflite.com/sl100.html

It has two chute deployment altitudes - small chute at the top of the
launch, bigger one near the ground, so drift is minimized.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)