Gather local wind data

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

Good that you are making progress, Anders! Keep us posted!

Steve