Gather local wind data

On Friday, September 14, 2012 9:29:31 AM UTC-4, Tony wrote:
On Friday, September 14, 2012 8:12:25 AM UTC-5, 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 he http://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



Temp and dew point readings would be most important. what is the approximate cost for each unit? I could definitely see this being used during contests to get a local real life sounding instead of depending on computer model forecasts. If cheap enough it potentially could be used for every weekend club operations too.

I agree. A higher release altitude is needed -- minimum 2km for US East Coast
or Europe; as much as 6000m in the West where only airspace is the limit.
In the EDT time zone (UTC -4) the weather service data isn't available until
9am, which isn't long before the usual pilot meeting. Weather briefers
are stuck using model data based on measurements taken 10 hours earlier,
and checking at the last minute a measurement taken 100s of km away.
I don't know much about balloon parameters so I can't say exactly what this
will do to the sonde capabilities needed.

I could see this as being useful for wave camp, in which case a 7000m altitude
would be needed, plus a long slant range because the wind velocities would be
higher (100km/hr is typical for a wave day). However, that's an extreme case.
For wave flights we like to launch early in the day before convection starts,
so, again, we depend on stale measurements taken a long ways away.

-- Matt

Thank you for your comments!

I have used Windsond up to 2.5km altitude. The current solution can do higher but I haven't checked exactly how high. I understand you want as high as possible but at some point the increased technical demands starts affecting the price of a sounding. If there's much interest in this I'll look more into it and give a better answer.

I'm aiming for a price point under $150 per unit. The exchange rate is unfavorable for USD at the moment.

My biggest interest is in temperature versus altitude in the first 1KM to 1..5KM above the surface. This will let you know where the cap that might kill the day exists. I had started a project for this some years ago, and since the wind usually blows here in Kansas, I was looking to use a couple of kites to lift the package. It would always stay within the confines of the airport, and would have much lower recurring cost than a helium balloon. I would be intereted in a package that gets temperature and altitude either logged on board, or transmitted to a PC on the ground. And at $150 or so, I am very interested.

Steve Leonard

On 9/20/2012 9:25 AM, Steve Leonard wrote:
My biggest interest is in temperature versus altitude in the first
1KM to 1.5KM above the surface. This will let you know where the cap
that might kill the day exists. I had started a project for this
some years ago, and since the wind usually blows here in Kansas, I
was looking to use a couple of kites to lift the package. It would
always stay within the confines of the airport, and would have much
lower recurring cost than a helium balloon. I would be intereted in
a package that gets temperature and altitude either logged on board,
or transmitted to a PC on the ground. And at $150 or so, I am very
interested.

Have you found the NWS lapse rate forecasts inadequate?

http://rucsoundings.noaa.gov/

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

On Thursday, September 20, 2012 7:35:02 PM UTC-5, Eric Greenwell wrote:
On 9/20/2012 9:25 AM, Steve Leonard wrote: My biggest interest is in temperature versus altitude in the first 1KM to 1.5KM above the surface. This will let you know where the cap that might kill the day exists. I had started a project for this some years ago, and since the wind usually blows here in Kansas, I was looking to use a couple of kites to lift the package. It would always stay within the confines of the airport, and would have much lower recurring cost than a helium balloon. I would be intereted in a package that gets temperature and altitude either logged on board, or transmitted to a PC on the ground. And at $150 or so, I am very interested. Have you found the NWS lapse rate forecasts inadequate? http://rucsoundings.noaa.gov/ -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)

Usually the soundings there are pretty good but we've also gone through spells where we had inversions that the models just weren't catching. Sometimes this has gone on for weeks, like for 2 or 3 weeks last June when the models were all predicting great soaring when in fact there was a hard inversion at about 5000 MSL and it totally sucked.

I think there is some real benefit to having actual measured real life data instead of a computer model. At 150 per unit, especially if you can reliably retrieve the transmitter, I think it would be worth it.

On 9/21/2012 2:22 PM, Tony wrote:
On Thursday, September 20, 2012 7:35:02 PM UTC-5, Eric Greenwell
Have you found the NWS lapse rate forecasts
inadequate? http://rucsoundings.noaa.gov/ -- Eric Greenwell -
Washington State, USA (change ".netto" to ".us" to email me)

Usually the soundings there are pretty good but we've also gone
through spells where we had inversions that the models just weren't
catching. Sometimes this has gone on for weeks, like for 2 or 3 weeks
last June when the models were all predicting great soaring when in
fact there was a hard inversion at about 5000 MSL and it totally
sucked.

I think there is some real benefit to having actual measured real
life data instead of a computer model. At 150 per unit, especially if
you can reliably retrieve the transmitter, I think it would be worth
it.

Maybe you could talk an ultralight pilot into doing it for the gas
money. They like to fly in the morning anyway, and having a mission
would delight the ones I know. There are $60-$100 USB temperature and
humidity recorders that could easily carried (a few oz.), downloaded to
a PC after landing, then the file emailed to you.

Here are some examples:

http://www.thermoworks.com/products/...b_loggers.html

The trick is selecting one with a proper response time to get an OK
lapse rate. The one I have is about a minute - too slow for a climbing
aircraft measurement - but I saw one of 20 seconds (probably OK for a
500fpm climb rate). That would give a decent lapse rate.

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

On Friday, September 21, 2012 6:11:53 PM UTC-4, Eric Greenwell wrote:
There are $60-$100 USB temperature and

humidity recorders that could easily carried (a few oz.), downloaded to

a PC after landing, then the file emailed to you.



Here are some examples:



http://www.thermoworks.com/products/...b_loggers.html



The trick is selecting one with a proper response time to get an OK

lapse rate. The one I have is about a minute - too slow for a climbing

aircraft measurement - but I saw one of 20 seconds (probably OK for a

500fpm climb rate). That would give a decent lapse rate.



--

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

email me)

Interesting. Aside from the morning sounding, it would be very interesting to gather data for after-the-fact comparison of model forecast sounding vs.. actual. These don't look perfect (the accuracy is a little coarser than I'd like), but I could see fixing one of these under the wing of our club Grob and doing some interesting studies. My suspicion is that many of the misses where we are (NJ/PA area) have less to do with the basic atmospheric lapse rate and more to do with getting the surface dewpoints and amount of surface heating wrong, but this would be a good way to test that out.

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.

I sense the technology is available now, but maybe just not for a mass market. Hoping Andres is still watching this thread.

Steve