Gather local wind data

On 9/24/2012 6:25 AM, Steve Leonard wrote:
On Monday, September 24, 2012 12:10:39 AM UTC-5, Eric Greenwell
wrote:

Here is a rocket logger: altitude, temperature - $80
http://www.perfectflite.com/sl100.html

May have to get one of those. But again rockets are not the way to
go for recurring cost. As I recall from talking with one of our
local rocket guys, they are $30 and up per shot. Don't mind a few
more bucks to get started, but hate recurring costs.

Thanks for the searching, Eric. If I get one, I will let you know
how the kite flying and data collecting goes. That one might have
issues, as the launch, climb, and recovery of the kite will likely be
more than 9 minutes. Reeling in 7000 feet of like takes a bit of
time!

Maybe use the old kite flyers trick of sending the instrument pack up
the string in a little pod with a sail, once the kite is at altitude.
Or, reverse it: have the pod slide down the string from the kite after
it's up, and have even quicker access to the data.

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

On Monday, September 24, 2012 12:00:59 PM UTC-5, Eric Greenwell wrote:

Maybe use the old kite flyers trick of sending the instrument pack up the string in a little pod with a sail, once the kite is at altitude. Or, reverse it: have the pod slide down the string from the kite after it's up, and have even quicker access to the data.

-- Eric Greenwell

Well, the package would have to be on the second kite in my system. It seems that one kite on 1000 feet of string got to about 800 feet based on the altimeter watch that was used in initial testing. Adding another 1000 feet of string only got about 400 feet more altitude. Bigger kite needed. But, what to do with the smaller one, since the money was invested? Tie it to the main line on a 100 or so foot tether, and let it help in lifting the line. So, I won't have a 7000 foot long, clear shot up the line. I did learn some interesting dynamics of an intermediate, line lifting kite, though.

Interested in seeing the dynamic of a powered winch to reel the line in. Will have the effect of increased wind speed for the kites, so they should climb a little higher. First attempts were with people grabbing the line and walking it towards the reel (yes, the first 200 feet or so of the line was only 4-6 feet off the ground when we had, I believe, 3000 feet of line). I have seen what this line put on a Home Depot Extension cord reel does over time. I now have a big mess of kite string, as it contracted and split the ends off of the reel!

Steve

On Mon, 24 Sep 2012 10:53:55 -0700, Steve Leonard wrote:

Interested in seeing the dynamic of a powered winch to reel the line in.
Will have the effect of increased wind speed for the kites, so they
should climb a little higher. First attempts were with people grabbing
the line and walking it towards the reel (yes, the first 200 feet or so
of the line was only 4-6 feet off the ground when we had, I believe,
3000 feet of line). I have seen what this line put on a Home Depot
Extension cord reel does over time. I now have a big mess of kite
string, as it contracted and split the ends off of the reel!

Talking to these guys may give some pointers to what can be done:
http://www.kiterecord.org/kiterecord/

They've had a single kite up to 10,466 ft, but it was a big one: 16 m^2

I also remember hearing that US meterologists got the top kite in a
string to 25,000 ft in the late 1930s, but can't find a reference to
quote.

I'd say that a rocket instrument package would be a good starting point
because its light: put it under a fairly large Rogallo-type kite and fly
it on light, low drag line (Spectra or Kevlar?) and you should get the
height you want. Light and low drag and large are all important since the
kit's lift must support the weight of the whole rig as well as offsetting
the drag of line and kite. Some sort of winch would be good too, even if
its only a geared (multiplier) sea-fishing reel.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |