Thermal locators!

Serusly, maybe Dr. Jack can log in with his forecast of when he thinks real-time moving map cockpit displays of current thermals, or (let's not be unreasonable here) 1-hr old thermals will be available.

Or does he think there is a physical limit to this problem, beyond which we cannot go? (Like 7 A-h batteries)

Winter food for thot

How about this to help you make the best of thermals you have bumped into. Does anyone have any practical experience of this device ?
http://www.themi.de/Themi%20Centering%20Device.htm

Anyone used the Winpilot Pro Climb maximiser, does it work ?

John

At 16:54 19 November 2003, Bob Johnson wrote:

All

As I'm still trying to make Silver distance I well appreciate the desire for a thermal road map. However, mystery is part of the marvel of soaring. For certainty all one need do is fill the tanks on a power plane and go. No mystery in that. Tom Knauff reports the Themi works. See eglider.com for a review.

Regards

The first thing that needs to be established is data uplink to a glider so that _presently_ existing observations (eg satellite images) or predictions (eg updated BLIPMAPs) can be obtained, and I'm not an expert on when that will occur. (Milt Hare used to solve the updating problem by calling his glider-rated wife from the air and having her describe the latest BLIPMAP predictions to him, but I don't think that will be a common practice!). Observation of individual thermals is difficult enough for researchers (typically taking two lidar/radars) so I can't see that being feasible in my lifetime, and in any case thermals have relatively short lifetimes - what would be more practical would be observation of the general 'convective status' at specific locations, which is possible using special temperature-profile sounders (not the sounders used for upper-level wind speeds) - but at present those are few and far between (an example of such sounder output can be seen at http://www.weather.nps.navy.mil/profiler/ord_mix.gif )

Check out the thermal finder in WinPilot. WinPilot XP takes logger flights, IGC files, and produces a thermal data base. You need to have WinPilot XP for your desktop computer and WinPilot ADV or PRO for your Ipaq. I personally have six years of data for Montague and all the contest flights in the area, in my Montaque thermal data base. WinPilot can be set to limit the thermals by sun position and wind direction. The thermals can be turned on and off by assigning a button on the front of the Ipaq. Many contest flights are available for download for most US contest sites. One interesting thing is the thermals that were found by contest pilots in areas that locals very rarely fly. I believe there is also a thermal data base available for the Minden area. I will add a thermal database page for WinPilot users to my website in the next couple of days. If you have a thermal database for you area and want it placed on my web please email it to me.

Richard www.craggyaero.com

I heard about this feature of WinPilot at the SSA convention earlier this year. Amazing.

Now, it will be interesting to see the effect to the database(s) as land-use changes take place. What happens to the burned areas (California?) or timbered areas or locations that were purely agricultural and change to residential or commercial?

I don't have WinPilot, but I think it would be interesting to know what happens.

Ray Lovinggood Carrboro, North Carolina, USA

At 15:12 20 November 2003, Richard Pfiffner wrote:

The closest thing I have seen for thermal locators is WinPilot's data base for thermals. you can enter as many thermals for a site that you want to and have a read out on you PocketPC Winpilot program that shows where thermals have historically been located given a particular day, time of day and wind variables. Works pretty good, but if you have flown many years at one site you know where the thermals are anyway, if there are any thermals that is.

G. Kemp

How does such a device work? There is on the picture the indication '915 MHz' which seems to imply that it uses radio high frequency, but

In additon to the HF radio signal an acoustic pulse is sent which alters the propagation speed depending on temperature. The height to which it can reach is limited by the strength of the acoustic signal and so is not practical at higher altitudes. See

DrJack

Those are surface measurements from a normal set of surface weather sensors. The one you mention is surface wind direction, the dramatic changes being onshore/offshore sea-breeze flow since the site is located within 2 miles of the ocean.