Thermal mapping

[John]

Here is a thought:

Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
for the baby. Slight breeze. Clearly could tell the entire airflow
pattern in the back yard....even a little ridge lift over the glider
trailer!

Wonder if you could add a soap bubble machine to a sailplane? Turn it
on when you first hit a thermal and a trail of bubbles is created.
After one circle, just fly toward the highest bubbles and that is
where the thermal's core is.

I could see the bubbles about 200 feet away, but might could add a
color die to enhance visibility further.

Any thoughts on this?

[Stewart Kissel]

Assuming this is not a troll-

In the spring I like to use 'controlled' burns in the
forests for this. I can spot the smoke from a long
way, and by examing the plumes try and figure out the
strongest lift areas. Depending on how high above
the fires I can use the smoke smell as an olfactory
vario.

Typically these burns are done with an unstable atmosphere
to keep the smoke from sitting low in an inversion.
Once fire season gets going again I don't venture
near the conflagarations, but sometimes watch them
from afar.


At 15:24 19 April 2004, John wrote:
>Here is a thought:
>
>Was in the back yard making thousands of soap bubbles
>(Mr. Bubbles)
>for the baby. Slight breeze. Clearly could tell the
>entire airflow
>pattern in the back yard....even a little ridge lift
>over the glider
>trailer!
>
>Wonder if you could add a soap bubble machine to a
>sailplane? Turn it
>on when you first hit a thermal and a trail of bubbles
>is created.
>After one circle, just fly toward the highest bubbles
>and that is
>where the thermal's core is.
>
>I could see the bubbles about 200 feet away, but might
>could add a
>color die to enhance visibility further.
>
>Any thoughts on this?
>

[Shawn Curry]

John wrote:

> Here is a thought:
>
> Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
> for the baby. Slight breeze. Clearly could tell the entire airflow
> pattern in the back yard....even a little ridge lift over the glider
> trailer!
>
> Wonder if you could add a soap bubble machine to a sailplane? Turn it
> on when you first hit a thermal and a trail of bubbles is created.
> After one circle, just fly toward the highest bubbles and that is
> where the thermal's core is.
>
> I could see the bubbles about 200 feet away, but might could add a
> color die to enhance visibility further.
>
> Any thoughts on this?

You should install a sound system and play this guy's music.
http://www.welkshow.com/welk.html
But maybe you could integrate a bubble generator with a pilot relief
system. Its already an over-board liquid dispensing system, plus you'd
have the added benefit of discouraging leachers, at least those that are
familiar with your system.
:-)

Seriously, I'd use dust or smoke. I suspect the airspeed would shred
all but the smallest bubbles. Also, would enough bubbles persist long
enough to be seen? I do think visibility of bubbles would be the
biggest problem. Can you make bubbles with glitter in the solution? Or
dispense with the bubbles and just funnel the glitter out the vent
window. Hmm, sink rate is probably more than the glider's so it would
only work in a strong thermal. Also could clog the pitot system.


Shawn

[Bill Daniels]

"John" > wrote in message
om...
> Here is a thought:
>
> Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
> for the baby. Slight breeze. Clearly could tell the entire airflow
> pattern in the back yard....even a little ridge lift over the glider
> trailer!
>
> Wonder if you could add a soap bubble machine to a sailplane? Turn it
> on when you first hit a thermal and a trail of bubbles is created.
> After one circle, just fly toward the highest bubbles and that is
> where the thermal's core is.
>
> I could see the bubbles about 200 feet away, but might could add a
> color die to enhance visibility further.
>
> Any thoughts on this?

Sounds maybe a little silly but it's sound thinking. Way back in the 1960's
I worked for Paul McCready at a little company called Meteorology Research
in Pasadena, California. One of my projects was to develop techniques to
map boundary layer turbulence.

We had made the same observation you did that soap bubbles trace airflow
very well. The first idea was to generate a bunch of bubbles, film them
with a pair of carefully calibrated movie cameras to get 3D data and then
analyze the film to plot the individual bubble trajectories. We thought we
could do a lot of interesting science with this data. (With the Lawrence
Welk TV show the rage, you can imagine the reputation this project quickly
developed - Welk was a band leader who used soap bubbles on his set to
highlight his "champagne music")

There were several problems. First, soap bubbles don't last very long -
maybe 20-30 seconds outdoors. (It seems UV degrades the soap films.)
Second, even with dye in the soap solution, bubbles are nearly invisible.
We tried filling them with colored smoke which reduced the average bubble
lifespan to about a second.

Tackling the bubble half life problem head on, I sought the help of some
chemists at CalTech who recommended adding polyvinyl alcohol to the bubble
solution. With PVA in the solution, a solid PVA film formed as the PVA was
polymerized by UV. The PVA+soap film seemed to be pretty gas tight and the
bubbles lasted a long time, but now they were heavy and quickly sank to the
ground.

Back at the drawing board, we dreamed up a modified bubble machine that
allowed the introduction of a carefully controlled amount of helium. With
this device pouring out bubbles, we could adjust the helium needle valve
until the bubbles showed neutral buoyancy. Now the bubbles traced the
airflow streamlines perfectly, we just couldn't see them very well and the
cameras didn't see them at all. Welk wasn't impressed.

Now we were delving into bubble optics. We knew that tiny glass spheres
would reflect light back to the source since that is what is used in
reflective paint on highway signs. Would bubbles do the same? Yes, but
altogether too well. The little glass spheres in reflective paint are
deliberately flawed. Our bubbles were perfect so they reflected a
searchlight beam directly back into the searchlight. If you were standing
next to the searchlight, you saw no reflections.

Now we built a camera mount with a huge beamsplitter so the cameras could
look right down the axis of the searchlight beam. Success! Our little
bubbles shown like stars tracing every little twist and turn of the airflow.

So here's the scene, high noon in downtown Pasadena with a couple of rented
Hollywood carbon arc searchlights, 35mm movie cameras and billions of
bubbles drifting around the buildings. It took several hours and the
company attorney to convince the authorities we weren't filming a movie and
didn't need a permit to do so.

We moved the project to the desert. It expanded from bubbles to Mylar
balloons, dozens of cameras and produced mountains of data. Unfortunately,
the IBM 360 punch card computer we used wasn't up to the task of analyzing
all the data. Last I heard, the data were still being re-analyzed by each
new generation of supercomputer.

So, would your idea work? I proved it would but all that heavy gear will be
pretty hard to get into a glider. Throwing out bits of toilet paper
probably works better. Hmmm, Lets see.....what would a toilet paper
dispensing machine look like...

Bill Daniels

[Bob Kibby]

This is not my idea but it sounds pretty good to me. "Doug" at Texas Soaring
Association (TSA) folds up TSA tow tickets so that they have two helicopter
blades and a body. As kids, we used to do this and throw them in the air and
watch them rotate and disappear in a thermal or rotate to the ground. When
"Doug" finds a thermal he throws a few of these folded helicopter tow
tickets out the vent window. They tend to go to the core of the thermal and
he follows them up. Don't anyone report "Doug" for excessive use of TSA tow
tickets or I will be in big trouble.

Hoping to center the thermal,
Bob Kibby "2BK"


--


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from MailFrontier, Inc. http://info.mailfrontier.com

"John" > wrote in message
om...
> Here is a thought:
>
> Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
> for the baby. Slight breeze. Clearly could tell the entire airflow
> pattern in the back yard....even a little ridge lift over the glider
> trailer!
>
> Wonder if you could add a soap bubble machine to a sailplane? Turn it
> on when you first hit a thermal and a trail of bubbles is created.
> After one circle, just fly toward the highest bubbles and that is
> where the thermal's core is.
>
> I could see the bubbles about 200 feet away, but might could add a
> color die to enhance visibility further.
>
> Any thoughts on this?

[Wallace Berry]

>
> So, would your idea work? I proved it would but all that heavy gear will be
> pretty hard to get into a glider. Throwing out bits of toilet paper
> probably works better. Hmmm, Lets see.....what would a toilet paper
> dispensing machine look like...
>
> Bill Daniels
>


Someone beat you to it. Ted Teach had a 1-26 with a toilet paper
dispensing mechanism in the turtledeck. It was a little trapdoor with a
cutting edge. Open the door and toilet paper unrolled into the
slipstream. Close the door and it severed the paper. Repeatedly opening
and closing the door supposedly dispensed tp chaff to be followed as a
thermal marker. Teach's 1-26 also had a reprofiled nose and canopy and
doors that enclosed the landing gear (retractable gear being against the
rules in 1-26 racing. Mark Connor later had this 1-26 and was undoing
all the "Teachisms" on it.


People in this sport tend to be inventive. Wierd, but inventive...

[Duane Eisenbeiss]

"Bubbles, toliet paper, and bent tow tickets seem to center thermals by
themselfs. Free flight model airplanes do a good job of centering thermals
by themself. Ever consider what might happen if we just trimed out our
sailplanes and kept our hands off of the controls?

Duane

[Eric Greenwell]

Duane Eisenbeiss wrote:

> "Bubbles, toliet paper, and bent tow tickets seem to center thermals by
> themselfs. Free flight model airplanes do a good job of centering thermals
> by themself. Ever consider what might happen if we just trimed out our
> sailplanes and kept our hands off of the controls?

How do we know they are centered? All I knew is the model was going up,
but I didn't know if it would do better in a different location.

I know just flying steady circles with the least amount of adjustment
needed to maintain attitude doesn't work well for me!

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Hank Nixon]

(John) wrote in message >...
> Here is a thought:
>
> Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
> for the baby. Slight breeze. Clearly could tell the entire airflow
> pattern in the back yard....even a little ridge lift over the glider
> trailer!
>
> Wonder if you could add a soap bubble machine to a sailplane? Turn it
> on when you first hit a thermal and a trail of bubbles is created.
> After one circle, just fly toward the highest bubbles and that is
> where the thermal's core is.
>
> I could see the bubbles about 200 feet away, but might could add a
> color die to enhance visibility further.
>
> Any thoughts on this?


This has been tried on and off for more than 50 years.
Popular markers were baloons, toilet paper, and most recently
published a bunch of years ago, newspaper.
Harry Senn found that newspaper was about what it took to be able to
see. Soaring had a very funny article on this experiment with classic
cartoon with it.
Reality- it doesn't work in the real world.
UH

[Bryan]

How about throwing dollar bills out the canopy sliding window? That would
be a more direct way of wasting money on soaring and would also attract non
fliers to the sport.


"John" > wrote in message
om...
> Here is a thought:
>
> Was in the back yard making thousands of soap bubbles (Mr. Bubbles)
> for the baby. Slight breeze. Clearly could tell the entire airflow
> pattern in the back yard....even a little ridge lift over the glider
> trailer!
>
> Wonder if you could add a soap bubble machine to a sailplane? Turn it
> on when you first hit a thermal and a trail of bubbles is created.
> After one circle, just fly toward the highest bubbles and that is
> where the thermal's core is.
>
> I could see the bubbles about 200 feet away, but might could add a
> color die to enhance visibility further.
>
> Any thoughts on this?

[Bill Daniels]

"Wallace Berry" > wrote in message
...
>
> >
> > So, would your idea work? I proved it would but all that heavy gear
will be
> > pretty hard to get into a glider. Throwing out bits of toilet paper
> > probably works better. Hmmm, Lets see.....what would a toilet paper
> > dispensing machine look like...
> >
> > Bill Daniels
> >
>
>
> Someone beat you to it. Ted Teach had a 1-26 with a toilet paper
> dispensing mechanism in the turtledeck. It was a little trapdoor with a
> cutting edge. Open the door and toilet paper unrolled into the
> slipstream. Close the door and it severed the paper. Repeatedly opening
> and closing the door supposedly dispensed tp chaff to be followed as a
> thermal marker. Teach's 1-26 also had a reprofiled nose and canopy and
> doors that enclosed the landing gear (retractable gear being against the
> rules in 1-26 racing. Mark Connor later had this 1-26 and was undoing
> all the "Teachisms" on it.

In all seriousness, the bubble experiments produced some very good insights
in low level convective airflow. Neutrally buoyant bubbles have no
aerodynamic qualities of their own so if they are seen to move, it is
because airflow is pushing them. Bits of paper and other debris do have
some aerodynamic qualities so the data is corrupted. Up to that point there
were several studies that used smoke, but that can't be analyzed
numerically. Discrete bubbles provided a means to measure speed and
direction of airflow in 3D to high precision.

Later, larger scale experiments with Mylar balloons were even more
interesting. First pairs would be released and tracked for many miles by
radar. Eventually, large numbers of these balloons were released
simultaneously along a crosswind line in thermic conditions and watched by
radar as they traced out thermal streets.

Today, most work of this kind is done with LIDAR (Laser Radar) which can
track naturally occurring tiny aerosols of pollen and dust revealing the 3D
structure of airflow with great precision over a large area in real time.

Now, putting a LIDAR in a glider WOULD be interesting.

Bill Daniels

[Rory O'Conor]

>were several studies that used smoke, but that can't
be analyzed

I was wondering about orange smoke flares but I can
see that one might either fill the cockpit with an
impenetrable haze or knock chucks off the horizontal
stabiliser. Both would cause a greater degradation of
performance than a need to pee.

I can also see that flares attached to balloons are
difficult to push through the clear view panel. But
maybe the T21 will come in handy!

I wonder how "skywriters" make their smoke and what
the effect of thermalling with a smoke dispenser would
be like, maybe personal IMC conditions.

Thermals could be colour coded according to strength.

If the dispenser was attached to the vario, then the
smoke could be varied by colour according to lift,
making it easier to move towards the green smoke and
away from the red smoke. - with the potential to
reverse the colours if needed to confuse the unwanted.

>Today, most work of this kind is done with LIDAR
>(Laser Radar) which can track naturally occurring
> tiny aerosols of pollen and dust revealing the 3D
> structure of airflow with great precision over a
> large area in real time.

Has anyone any leads to accessible output on the
results of LIDAR?

Rory

[iPilot]

Actually for thermal marking purporses smoke would work pretty fine. But I
don't know any smoke machine which is small enough to fit to the glider and
which is controllable. For aerobatics they just fit smoking cartridges that
burn to the end after ignition, but thermal marking needs some repeatable 2
sec buffs of somke.
There's another problem with bubbles. The only reasonable place to put it is
on top of the rear fuselage. But then you spill the vertical fin with wet
bubbles and this harms your L/D.

Regards,
Kaido



"Bill Daniels" > wrote in message
news:t6ahc.33650$ru4.33232@attbi_s52...
>
> "Wallace Berry" > wrote in message
> ...
> >
> > >
> > > So, would your idea work? I proved it would but all that heavy gear
> will be
> > > pretty hard to get into a glider. Throwing out bits of toilet paper
> > > probably works better. Hmmm, Lets see.....what would a toilet paper
> > > dispensing machine look like...
> > >
> > > Bill Daniels
> > >
> >
> >
> > Someone beat you to it. Ted Teach had a 1-26 with a toilet paper
> > dispensing mechanism in the turtledeck. It was a little trapdoor with a
> > cutting edge. Open the door and toilet paper unrolled into the
> > slipstream. Close the door and it severed the paper. Repeatedly opening
> > and closing the door supposedly dispensed tp chaff to be followed as a
> > thermal marker. Teach's 1-26 also had a reprofiled nose and canopy and
> > doors that enclosed the landing gear (retractable gear being against the
> > rules in 1-26 racing. Mark Connor later had this 1-26 and was undoing
> > all the "Teachisms" on it.
>
> In all seriousness, the bubble experiments produced some very good
insights
> in low level convective airflow. Neutrally buoyant bubbles have no
> aerodynamic qualities of their own so if they are seen to move, it is
> because airflow is pushing them. Bits of paper and other debris do have
> some aerodynamic qualities so the data is corrupted. Up to that point
there
> were several studies that used smoke, but that can't be analyzed
> numerically. Discrete bubbles provided a means to measure speed and
> direction of airflow in 3D to high precision.
>
> Later, larger scale experiments with Mylar balloons were even more
> interesting. First pairs would be released and tracked for many miles by
> radar. Eventually, large numbers of these balloons were released
> simultaneously along a crosswind line in thermic conditions and watched by
> radar as they traced out thermal streets.
>
> Today, most work of this kind is done with LIDAR (Laser Radar) which can
> track naturally occurring tiny aerosols of pollen and dust revealing the
3D
> structure of airflow with great precision over a large area in real time.
>
> Now, putting a LIDAR in a glider WOULD be interesting.
>
> Bill Daniels
>

[Ralph Jones]

On Mon, 19 Apr 2004 16:39:49 GMT, "Bill Daniels" >
wrote:

[snip]
>So, would your idea work? I proved it would but all that heavy gear will be
>pretty hard to get into a glider. Throwing out bits of toilet paper
>probably works better. Hmmm, Lets see.....what would a toilet paper
>dispensing machine look like...

A building with a sign saying "Ziff-Davis"?

rj

[Mike Koerner]

Perhaps NASA will help us with thermal locating. Quoting from a CNN article
currently at http://www.cnn.com/2004/TECH/space/04/20/dust.devil/index.html
:
Dust particles in a devil become electrified because they rub against one
another. It's like shuffling your feet across the carpet, the researchers
explained. But they figured the positive and negative particles would be
evenly mixed in a dust devil, keeping the overall electrical charge in
balance.

Instead, it turns out smaller particles tend to gain negative charge, and
the wind carries them higher.

Heavier, positive particles remain nearer the surface. The separation of
charges creates a giant battery. And because the particles are in motion, a
magnetic field is generated by the moving electrical charges, the
researchers explained.

They don't yet know for sure what to expect on Mars.

If dust on the red planet comes in a variety of sizes and compositions, as
expected, then dust devils there ought to be similarly electrified, the
scientists said. NASA could equip a future Mars landing craft with an
instrument to detect a dust devil's electric and magnetic fields.

Mike Koerner

"iPilot" > wrote in message
...
> Actually for thermal marking purporses smoke would work pretty fine. But I
> don't know any smoke machine which is small enough to fit to the glider
and
> which is controllable. For aerobatics they just fit smoking cartridges
that
> burn to the end after ignition, but thermal marking needs some repeatable
2
> sec buffs of somke.
> There's another problem with bubbles. The only reasonable place to put it
is
> on top of the rear fuselage. But then you spill the vertical fin with wet
> bubbles and this harms your L/D.
>
> Regards,
> Kaido
>
>
>
> "Bill Daniels" > wrote in message
> news:t6ahc.33650$ru4.33232@attbi_s52...
> >
> > "Wallace Berry" > wrote in message
> > ...
> > >
> > > >
> > > > So, would your idea work? I proved it would but all that heavy gear
> > will be
> > > > pretty hard to get into a glider. Throwing out bits of toilet paper
> > > > probably works better. Hmmm, Lets see.....what would a toilet paper
> > > > dispensing machine look like...
> > > >
> > > > Bill Daniels
> > > >
> > >
> > >
> > > Someone beat you to it. Ted Teach had a 1-26 with a toilet paper
> > > dispensing mechanism in the turtledeck. It was a little trapdoor with
a
> > > cutting edge. Open the door and toilet paper unrolled into the
> > > slipstream. Close the door and it severed the paper. Repeatedly
opening
> > > and closing the door supposedly dispensed tp chaff to be followed as a
> > > thermal marker. Teach's 1-26 also had a reprofiled nose and canopy and
> > > doors that enclosed the landing gear (retractable gear being against
the
> > > rules in 1-26 racing. Mark Connor later had this 1-26 and was undoing
> > > all the "Teachisms" on it.
> >
> > In all seriousness, the bubble experiments produced some very good
> insights
> > in low level convective airflow. Neutrally buoyant bubbles have no
> > aerodynamic qualities of their own so if they are seen to move, it is
> > because airflow is pushing them. Bits of paper and other debris do have
> > some aerodynamic qualities so the data is corrupted. Up to that point
> there
> > were several studies that used smoke, but that can't be analyzed
> > numerically. Discrete bubbles provided a means to measure speed and
> > direction of airflow in 3D to high precision.
> >
> > Later, larger scale experiments with Mylar balloons were even more
> > interesting. First pairs would be released and tracked for many miles
by
> > radar. Eventually, large numbers of these balloons were released
> > simultaneously along a crosswind line in thermic conditions and watched
by
> > radar as they traced out thermal streets.
> >
> > Today, most work of this kind is done with LIDAR (Laser Radar) which can

> > track naturally occurring tiny aerosols of pollen and dust revealing the
> 3D
> > structure of airflow with great precision over a large area in real
time.
> >
> > Now, putting a LIDAR in a glider WOULD be interesting.
> >
> > Bill Daniels
> >
>
>

[Hank Nixon]

"Mike Koerner" > wrote in message news:<AZohc.25214$Yf6.24446@fed1read07>...
> Perhaps NASA will help us with thermal locating. Quoting from a CNN article
> currently at http://www.cnn.com/2004/TECH/space/04/20/dust.devil/index.html
> :
> Dust particles in a devil become electrified because they rub against one
> another. It's like shuffling your feet across the carpet, the researchers
> explained. But they figured the positive and negative particles would be
> evenly mixed in a dust devil, keeping the overall electrical charge in
> balance.
>
> Instead, it turns out smaller particles tend to gain negative charge, and
> the wind carries them higher.
>
> Heavier, positive particles remain nearer the surface. The separation of
> charges creates a giant battery. And because the particles are in motion, a
> magnetic field is generated by the moving electrical charges, the
> researchers explained.
>
> They don't yet know for sure what to expect on Mars.

Famous modeler Maynard Hill studied varying electric charge related to
thermals about 25 or 30 years ago. As I recall he found that there was
a horizontal differential related to thermals.
So- he built a device to sense this and steer the model into the
thermal- so cool!
Then he tested it- When turned on it would not turn aircraft into the
thermal and in fact kept the wings absolutely level. Darn!
Why? It turns out that the vertical voltage potential around the
earth is far stronger than the horizontal one due to thermals.
The good news- He invented the electrostatic wing leveler.
UH
>
> If dust on the red planet comes in a variety of sizes and compositions, as
> expected, then dust devils there ought to be similarly electrified, the
> scientists said. NASA could equip a future Mars landing craft with an
> instrument to detect a dust devil's electric and magnetic fields.
>
> Mike Koerner
>
> "iPilot" > wrote in message
> ...
> > Actually for thermal marking purporses smoke would work pretty fine. But I
> > don't know any smoke machine which is small enough to fit to the glider
> and
> > which is controllable. For aerobatics they just fit smoking cartridges
> that
> > burn to the end after ignition, but thermal marking needs some repeatable
> 2
> > sec buffs of somke.
> > There's another problem with bubbles. The only reasonable place to put it
> is
> > on top of the rear fuselage. But then you spill the vertical fin with wet
> > bubbles and this harms your L/D.
> >
> > Regards,
> > Kaido
> >
> >
> >
> > "Bill Daniels" > wrote in message
> > news:t6ahc.33650$ru4.33232@attbi_s52...
> > >
> > > "Wallace Berry" > wrote in message
> > > ...
> > > >
> > > > >
> > > > > So, would your idea work? I proved it would but all that heavy gear
> will be
> > > > > pretty hard to get into a glider. Throwing out bits of toilet paper
> > > > > probably works better. Hmmm, Lets see.....what would a toilet paper
> > > > > dispensing machine look like...
> > > > >
> > > > > Bill Daniels
> > > > >
> > > >
> > > >
> > > > Someone beat you to it. Ted Teach had a 1-26 with a toilet paper
> > > > dispensing mechanism in the turtledeck. It was a little trapdoor with
> a
> > > > cutting edge. Open the door and toilet paper unrolled into the
> > > > slipstream. Close the door and it severed the paper. Repeatedly
> opening
> > > > and closing the door supposedly dispensed tp chaff to be followed as a
> > > > thermal marker. Teach's 1-26 also had a reprofiled nose and canopy and
> > > > doors that enclosed the landing gear (retractable gear being against
> the
> > > > rules in 1-26 racing. Mark Connor later had this 1-26 and was undoing
> > > > all the "Teachisms" on it.
> > >
> > > In all seriousness, the bubble experiments produced some very good
> insights
> > > in low level convective airflow. Neutrally buoyant bubbles have no
> > > aerodynamic qualities of their own so if they are seen to move, it is
> > > because airflow is pushing them. Bits of paper and other debris do have
> > > some aerodynamic qualities so the data is corrupted. Up to that point
> there
> > > were several studies that used smoke, but that can't be analyzed
> > > numerically. Discrete bubbles provided a means to measure speed and
> > > direction of airflow in 3D to high precision.
> > >
> > > Later, larger scale experiments with Mylar balloons were even more
> > > interesting. First pairs would be released and tracked for many miles
> by
> > > radar. Eventually, large numbers of these balloons were released
> > > simultaneously along a crosswind line in thermic conditions and watched
> by
> > > radar as they traced out thermal streets.
> > >
> > > Today, most work of this kind is done with LIDAR (Laser Radar) which can
>
> > > track naturally occurring tiny aerosols of pollen and dust revealing the
> 3D
> > > structure of airflow with great precision over a large area in real
> time.
> > >
> > > Now, putting a LIDAR in a glider WOULD be interesting.
> > >
> > > Bill Daniels
> > >
> >
> >

[Bill Daniels]

"Hank Nixon" > wrote in message > Famous modeler
Maynard Hill studied varying electric charge related to
> thermals about 25 or 30 years ago. As I recall he found that there was
> a horizontal differential related to thermals.
> So- he built a device to sense this and steer the model into the
> thermal- so cool!
> Then he tested it- When turned on it would not turn aircraft into the
> thermal and in fact kept the wings absolutely level. Darn!
> Why? It turns out that the vertical voltage potential around the
> earth is far stronger than the horizontal one due to thermals.
> The good news- He invented the electrostatic wing leveler.
> UH

It's fascinating that after decades of looking at thermals with the entire
electromagnetic spectrum, sampling the chemistry, listening to the sounds
and using every known sensing technology, the one consistent characteristic
is that they are updrafts! The effect of air motion on a glider is still
the only way they can be detected reliably.

LIDAR might open a tiny window for remote sensing. I have thought of a low
power, short range LIDAR that would sweep left and right of a line angled
down 45 degrees from the horizontal. It would look for bubbles rising from
below out to 100 meters or so to the front and left or right of the glider.
This would be enough to have a major impact on the probability of
encountering lift.

It would also be a great help in centering the best lift as it swept the sky
to the outside of the thermalling turn looking for stronger cores.

At the moment, I know of no way the weight and power consumption would allow
a LIDAR to fit in a glider.

Bill Daniels

[Martin Gregorie]

On 21 Apr 2004 06:04:12 -0700, (Hank Nixon)
wrote:

>"Mike Koerner" > wrote in message news:<AZohc.25214$Yf6.24446@fed1read07>...
>> Perhaps NASA will help us with thermal locating. Quoting from a CNN article
>> currently at http://www.cnn.com/2004/TECH/space/04/20/dust.devil/index.html
>> :
>> Dust particles in a devil become electrified because they rub against one
>> another. It's like shuffling your feet across the carpet, the researchers
>> explained. But they figured the positive and negative particles would be
>> evenly mixed in a dust devil, keeping the overall electrical charge in
>> balance.
>>
>> Instead, it turns out smaller particles tend to gain negative charge, and
>> the wind carries them higher.
>>
>> Heavier, positive particles remain nearer the surface. The separation of
>> charges creates a giant battery. And because the particles are in motion, a
>> magnetic field is generated by the moving electrical charges, the
>> researchers explained.
>>
>> They don't yet know for sure what to expect on Mars.
>
>Famous modeler Maynard Hill studied varying electric charge related to
>thermals about 25 or 30 years ago. As I recall he found that there was
>a horizontal differential related to thermals.
>So- he built a device to sense this and steer the model into the
>thermal- so cool!
>Then he tested it- When turned on it would not turn aircraft into the
>thermal and in fact kept the wings absolutely level. Darn!
>Why? It turns out that the vertical voltage potential around the
>earth is far stronger than the horizontal one due to thermals.
>The good news- He invented the electrostatic wing leveler.

Was that before or after he was involved in millimetric radar or LIDAR
at Langley? I don't know which - I don't recall the model magazine
story saying which was being tested.

Anyway, they saw strange woolly blobs and Maynard proved they were
thermals by putting an RC glider up and using two-radio from the radar
room to steer it into the blobs. I believe they discovered that the
radar was seeing dust and insects in the thermal column rather than
density gradients etc.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Bruce Greeff]

Rory O'Conor wrote:

>>were several studies that used smoke, but that can't
>
> be analyzed
>
> I was wondering about orange smoke flares but I can
> see that one might either fill the cockpit with an
> impenetrable haze or knock chucks off the horizontal
> stabiliser. Both would cause a greater degradation of
> performance than a need to pee.
>
> I can also see that flares attached to balloons are
> difficult to push through the clear view panel. But
> maybe the T21 will come in handy!
>
> I wonder how "skywriters" make their smoke and what
> the effect of thermalling with a smoke dispenser would
> be like, maybe personal IMC conditions.
>
> Thermals could be colour coded according to strength.
>
> If the dispenser was attached to the vario, then the
> smoke could be varied by colour according to lift,
> making it easier to move towards the green smoke and
> away from the red smoke. - with the potential to
> reverse the colours if needed to confuse the unwanted.
>
>
>>Today, most work of this kind is done with LIDAR
>>(Laser Radar) which can track naturally occurring
>>tiny aerosols of pollen and dust revealing the 3D
>>structure of airflow with great precision over a
>>large area in real time.
>
>
> Has anyone any leads to accessible output on the
> results of LIDAR?
>
> Rory
>
>
>
I thought the Northern soaring season had started already...

[Arnie]

I maybe mistaken, but I think there is something on the competition rules
that forbids the use of tools to "see" thermals ahead of the glider at a
distance of more than a wingspan or so...

So it could be good for centering thermals maybe, like the Themi, but
probably not more than that.

"Bill Daniels" > wrote in message
news:2Tuhc.171468$gA5.1991465@attbi_s03...
>
> "Hank Nixon" > wrote in message > Famous modeler
> Maynard Hill studied varying electric charge related to
> > thermals about 25 or 30 years ago. As I recall he found that there was
> > a horizontal differential related to thermals.
> > So- he built a device to sense this and steer the model into the
> > thermal- so cool!
> > Then he tested it- When turned on it would not turn aircraft into the
> > thermal and in fact kept the wings absolutely level. Darn!
> > Why? It turns out that the vertical voltage potential around the
> > earth is far stronger than the horizontal one due to thermals.
> > The good news- He invented the electrostatic wing leveler.
> > UH
>
> It's fascinating that after decades of looking at thermals with the entire
> electromagnetic spectrum, sampling the chemistry, listening to the sounds
> and using every known sensing technology, the one consistent
characteristic
> is that they are updrafts! The effect of air motion on a glider is still
> the only way they can be detected reliably.
>
> LIDAR might open a tiny window for remote sensing. I have thought of a
low
> power, short range LIDAR that would sweep left and right of a line angled
> down 45 degrees from the horizontal. It would look for bubbles rising
from
> below out to 100 meters or so to the front and left or right of the
glider.
> This would be enough to have a major impact on the probability of
> encountering lift.
>
> It would also be a great help in centering the best lift as it swept the
sky
> to the outside of the thermalling turn looking for stronger cores.
>
> At the moment, I know of no way the weight and power consumption would
allow
> a LIDAR to fit in a glider.
>
> Bill Daniels
>

[iPilot]

If anyone has free funds to play around with tinyfogger
http://www.tinyfogger.com/us/tiny-fogger.html I'd be interested in hearing about the results later
on. Funds needed are in range of $1200.

[iPilot]

There's a cheaper alternative too: Smoke spray

http://www.maplin.co.uk/products/module.asp?CartID=040422155302790&moduleno=20746



"iPilot" > wrote in message ...
> If anyone has free funds to play around with tinyfogger
> http://www.tinyfogger.com/us/tiny-fogger.html I'd be interested in hearing about the results later
> on. Funds needed are in range of $1200.
>
>
>
>

[Jeff Alu]

If you want to see some Dust Devils in actions, check out my short
movie of dust devils at El Mirage Dry Lake in Southern Cal:

http://www.animalu.com/pics/dd1.htm

I've only glided once. Anyone ever flown through a dust devil?

Jeff
http://www.animalu.com/pics/photos.htm

[Rudy Allemann]

"Duane Eisenbeiss" > wrote in message news:<3Q1hc.31080$yD1.92394@attbi_s54>...
> "Bubbles, toliet paper, and bent tow tickets seem to center thermals by
> themselfs. Free flight model airplanes do a good job of centering thermals
> by themself. Ever consider what might happen if we just trimed out our
> sailplanes and kept our hands off of the controls?
>
> Duane

Dick Schreder also suggested the idea back in the 60's. He used
Kleenex and I have tried it myself several times. The mechanics are
easy. Open the side window and with your free hand pull out a Kleenex
from the box (pop-up type), hold the sheet near the window and let go.
Out it goes and do another. In one circle in a thermal you can drop
ten or more. The sheets are fairly visible. You then continue flying
the circle and observe any sheets that are higher than you are. steer
toward them. In normal soaring it isn't much better than using the
vario but I used to think that when desparately low it might be a
useful last chance.

Rudy Allemann

[Mark James Boyd]

In article >, iPilot > wrote:
>There's a cheaper alternative too: Smoke spray

How about dry ice? A big hunk right behind the canopy? :P

--

------------+
Mark Boyd
Avenal, California, USA

[Tim Ward]

"Mark James Boyd" > wrote in message
news:408891f8$1@darkstar...
> In article >, iPilot >
wrote:
> >There's a cheaper alternative too: Smoke spray
>
> How about dry ice? A big hunk right behind the canopy? :P
>
> --
>
> ------------+
> Mark Boyd
> Avenal, California, USA

I'm pretty sure you're kidding, but somehow filling a very small cockpit
with carbon dioxide just seems like a really poor idea.

Tim Ward

[iPilot]

Pretty good shots on your gallery. Kudos. Devil movie is also pretty "shaky". Good work.


"Jeff Alu" > wrote in message
...
> If you want to see some Dust Devils in actions, check out my short
> movie of dust devils at El Mirage Dry Lake in Southern Cal:
>
> http://www.animalu.com/pics/dd1.htm
>
> I've only glided once. Anyone ever flown through a dust devil?
>
> Jeff
> http://www.animalu.com/pics/photos.htm

[Jeff Alu]

Thanks, glad you like. I would love to see some of those Dust Devils from
above!

Jeff

"iPilot" > wrote in message
...
> Pretty good shots on your gallery. Kudos. Devil movie is also pretty
"shaky". Good work.
>
>
> "Jeff Alu" > wrote in message
> ...
> > If you want to see some Dust Devils in actions, check out my short
> > movie of dust devils at El Mirage Dry Lake in Southern Cal:
> >
> > http://www.animalu.com/pics/dd1.htm
> >
> > I've only glided once. Anyone ever flown through a dust devil?
> >
> > Jeff
> > http://www.animalu.com/pics/photos.htm
>
>

[Norbas]

i´ve an old (70+) friend that used to launch small pieces of toilet paper or
even yellow pages from phone books, cut to pieces. It seems pretty effective
to him. Perhaps a good old habit from the 50's...

norbas
(lak12)

[Eric Greenwell]

Norbas wrote:
> i´ve an old (70+) friend that used to launch small pieces of toilet paper or
> even yellow pages from phone books, cut to pieces. It seems pretty effective
> to him. Perhaps a good old habit from the 50's...

I'm thinking it's not useful to have markers showing the lift where
you've already been - you know what's there, so why mark it? How about
something that disperses the markers over an area about two or three
times the size of a circle, so you can see what the lift is in places
you haven't flown through?

A toilet paper roll with a large firecracker in it, and a spring loaded
ejector would do the trick, but I sure wouldn't want to be in the
cockpit if the firecracker exploded before the roll was ejected!

I know! A trained flock of small soaring birds that you release when
desperate. They spread out over the area, circling when they find lift.
Once you start climbing, they return to the glider and crawl back
inside, ready for the next time you need their assistance.

Or, always team fly with 5 or 6 friends (buy them identical gliders if
you have to). Someone will find lift.

Or, do what I do: carry lift in the glider, and when you need some, turn
it on. It's a mature technology, available today from your glider
dealer. OK, maybe not available TODAY, but he'll be glad to order it for
you, and within a year, you'll have it. Or, buy a used one, and get it a
lot sooner.
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Martin Gregorie]

On Sun, 25 Apr 2004 08:00:04 -0700, Eric Greenwell
> wrote:

>I know! A trained flock of small soaring birds that you release when
>desperate. They spread out over the area, circling when they find lift.
>Once you start climbing, they return to the glider and crawl back
>inside, ready for the next time you need their assistance.
>
A month or so ago there was a nice piece on BBC Radio 4 about a hang
glider pilot who had a hen harrier that was trained to fly with him
and even to sit on a perch on his glider. He said that when lift was
strong he'd launch and gain height before letting his raptor fly with
him, but in weak, dodgy conditions the bird was flown first. He'd
launch and join her once she'd found a thermal.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Eric Greenwell]

Martin Gregorie wrote:
> On Sun, 25 Apr 2004 08:00:04 -0700, Eric Greenwell
> > wrote:
>
>
>>I know! A trained flock of small soaring birds that you release when
>>desperate. They spread out over the area, circling when they find lift.
>>Once you start climbing, they return to the glider and crawl back
>>inside, ready for the next time you need their assistance.
>>
>
> A month or so ago there was a nice piece on BBC Radio 4 about a hang
> glider pilot who had a hen harrier that was trained to fly with him
> and even to sit on a perch on his glider. He said that when lift was
> strong he'd launch and gain height before letting his raptor fly with
> him, but in weak, dodgy conditions the bird was flown first. He'd
> launch and join her once she'd found a thermal.

That sounds better than the flock of small birds: one smart bird would
be easier to handle. Of course, you'd want one with sufficient top speed
to catch the glider and crawl back inside. Maybe a motorglider with the
motor removed, so there would be hatch on the fuselage for the bird to
travel in.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[ADP]

In the spring and summer around lake Tahoe, there are flocks of American
White Pelicans that soar in groups of 4 to 6 or more.
They are particularly visible around Truckee, CA. I have joined them in
their soaring endeavors and managed to stay with them
for a while. I only wish that I could turn as well as they were able to.
We are talking here of soaring flocks of pelicans at and above 7000 ft.
Don't know why they do it but perhaps just for fun. They may be Jonathan
Livingston Seagull's distant relatives!
Looking for pelicans may be a new thermal indicator.

Allan




"Eric Greenwell" > wrote in message
...
> Martin Gregorie wrote:
>> On Sun, 25 Apr 2004 08:00:04 -0700, Eric Greenwell
>> > wrote:
>>
>>
>>>I know! A trained flock of small soaring birds that you release when
>>>desperate. They spread out over the area, circling when they find lift.
>>>Once you start climbing, they return to the glider and crawl back inside,
>>>ready for the next time you need their assistance.

[Mike Lindsay]

In article >, Martin Gregorie
> writes
>On Sun, 25 Apr 2004 08:00:04 -0700, Eric Greenwell
> wrote:
>
>>I know! A trained flock of small soaring birds that you release when
>>desperate. They spread out over the area, circling when they find lift.
>>Once you start climbing, they return to the glider and crawl back
>>inside, ready for the next time you need their assistance.
>>
>A month or so ago there was a nice piece on BBC Radio 4 about a hang
>glider pilot who had a hen harrier that was trained to fly with him
>and even to sit on a perch on his glider. He said that when lift was
>strong he'd launch and gain height before letting his raptor fly with
>him, but in weak, dodgy conditions the bird was flown first. He'd
>launch and join her once she'd found a thermal.
>
In the biography of Hanna Reich there was a story that the
German team who took some gliders to S America in 1937 used to join the
local vultures in thermals.
They decided it would be a good idea to take some home to
Germany so they could leach on to them there. But when the ship got to
Bremen, the vultures had got so fat and heavy they couldn't get
airborne.
--
Mike Lindsay

[Michael]

> > Has anyone any leads to accessible output on the
> > results of LIDAR?
> >
> > Rory
> >
> >
> >
> I thought the Northern soaring season had started already...


Hi Folks,

As one instructor down under in OZ explained cristal clear,
when the sun is shining, we would have 400 degrees (F or C)
on the ground if there wouldn't be any efficient convection.

Hence, whenever you feel a comfortable temperature outdoors
on a sunny day, there are plenty of thermals out there carrying
the heat away. Just fly straight on your course and you will
hit them.....

Cheers
Michael

[F.L. Whiteley]

"ADP" > wrote in message
...
> In the spring and summer around lake Tahoe, there are flocks of American
> White Pelicans that soar in groups of 4 to 6 or more.
> They are particularly visible around Truckee, CA. I have joined them in
> their soaring endeavors and managed to stay with them
> for a while. I only wish that I could turn as well as they were able to.
> We are talking here of soaring flocks of pelicans at and above 7000 ft.
> Don't know why they do it but perhaps just for fun. They may be Jonathan
> Livingston Seagull's distant relatives!
> Looking for pelicans may be a new thermal indicator.
>
> Allan
>
We also have these in Colorado and Wyoming. They are very large and visible
at a substantial distance.

Hawks are a bit more prevalent though.

Frank Whiteley