Thermal mapping

"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

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

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

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

Perhaps NASA will help us with thermal locating. Quoting from a CNN article
currently at http://www.cnn.com/2004/TECH/space/0...vil/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

"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/0...vil/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

"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

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/0...vil/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 :

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...

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