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)

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!

Steve

Steve,

Would XCSkies work for your needs? I see, looking at the map for
Hutchinson, that you should be getting lift up to 2,000' AGL right now!


"Steve Leonard" wrote in message
...
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!

Steve

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 11:48:37 AM UTC-5, Dan Marotta wrote:
Steve, Would XCSkies work for your needs? I see, looking at the map for Hutchinson, that you should be getting lift up to 2,000' AGL right now! "Steve Leonard" wrote in message ... 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! Steve

xcskies is still a model based forecast. when the model is broken it doesn't matter if dr. jack or xcskies is interpreting the data it still will be wrong.

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 |

On Monday, September 24, 2012 1:02:02 PM UTC-4, Tony wrote:
On Monday, September 24, 2012 11:48:37 AM UTC-5, Dan Marotta wrote:


xcskies is still a model based forecast. when the model is broken it doesn't matter if dr. jack or xcskies is interpreting the data it still will be wrong.

Yeah, but...

It seems to me that the models are more often wrong about the parts of the forecast that wouldn't be "fixed" by a local sounding.

There are obviously times (e.g. exact timing of a frontal passage) which can make a difference between a soarable day at the local airport and playing golf, but in such cases a morning sounding wouldn't matter. Similarly, we can have a perfectly good boundary layer in place but a pesky short-wave aloft produces a alto-cu layer just where we didn't need it, killing our heating. Again, that one wouldn't be caught by the local sounding. Same for advection of some slightly drier air that takes our day for 3/8 Cu to blue.

I'd be curious if Dan Gudgel or Walt Rogers would weigh in on this one. Maybe I'll just ask :-)

P3

I once toyed with an idea of putting a temp/rh/pressure logger on a RC
plane with an autopilot. It would climb on its own, gather data, come
back to the launch site and fly in circles until an operator turns on
a radio and guides it to a landing.

I decided against it because of legal issues. While I do not know all
the relevant laws, I am pretty sure that an amateur-built UAV flying
close to an airway (that's where my club is located) would be frowned
upon.

I am sure that unmanned balloons and rockets are subject to their own
regulations.

On the other hand, building a sensor package to be carried by an
ultralight or a kite would be relatively easy.

Bart


On Sep 14, 6:12*am, Anders Petersson wrote:
Hi
I have developed a system "Windsond" to gather local wind data at different altitudes in an easy way. This is done by launching a 60 liter helium balloon with electronics that transmits back sensor data as it ascends. On the ground, a laptop receives the data and displays diagrams of wind speed, direction and temperature.

The idea is not new, and weather balloons are indeed launched daily all over the world. The novel thing is the light weight and low cost, for a system adapted for altitudes up to 3000m. We use this for hot air balloons where we also recover the electronics again with a success rate around 80%.
More information and pictures hehttp://kiwiembedded.com/windsond/

From discussing with a glider pilot, it seems this could be interesting for your sport as well. But you also want humidity readings, right? I'm interested in your comments and what potential you see. Looking forward to hear from you either here or on email .

Thanks for your time,
/Anders Petersson
*Embedded systems designer

Hi again
I'm sorry I disappeared from the discussion. I thought I would get email notifications of new replies.

The technical solution has become more mature since September. It now supports humidity measurements. Radio range is much improved and testing will hopefully confirm support for altitudes of 7-9 km.
The weight is optimized to the point where 30 liters of helium should suffice. This makes a sounding very cheap as long as the electronics is recovered. We're looking into offering a variant for one-time use but haven't determined what pricing is possible yet.

As for alternatives, I don't see how a kite could measure winds and altitude is limited indeed. Results from a rocket would be inaccurate due to high vertical speed. In both cases, the payload can detach at peak altitude and take measurements while falling to the ground. That would mean the electronics still has to be retrieved some distance away.
A helium balloon is cheap but these other solutions would also work with Windsond. Approximate GPS coordinates of landing site together with loudspeaker, radio beacon and flashes of light makes it easy to recover.

We're now working to estimate the market to motivate production. In parallel, I'm doing development and testing. Your comments are valuable!

Regards
/Anders Petersson