Remote thermal detection

[Craig Funston]

We're getting closer. A fist size LIDAR for $250 thanks to the push for self driving cars.

https://www.technologyreview.com/s/602503/fist-sized-laser-scanner-to-make-autonomous-cars-less-ugly/?utm_campaign=internal&utm_medium=homepage&utm_source=top-stories_2&set=602506

Cheers,
7Q

[Bret Hess]

Can LIDAR detect the small changes in air density due to a thermal?

[Craig Funston]

Motion of particles in the air

[Tony[_5_]]

Awesome I can't wait!!

[[email protected]]

On Friday, September 30, 2016 at 6:21:27 AM UTC-5, Tony wrote:
> Awesome I can't wait!!

Here comes the end of this world as we know it.

[WAVEGURU]

We might as well all just stop flying and start playing Condor. Maybe then we could interest our youth? It's way too hard to soar the way we do it now and making it easier will bring soaring back to the level of popularity we use to enjoy? Or maybe we should remove ourselves from the cockpit and fly remotely?

Boggs

[[email protected]]

On Thursday, September 29, 2016 at 10:50:59 PM UTC-7, Craig Funston wrote:
> Motion of particles in the air

Not saying you are wrong, but what lidar unit can detect particles in the air? And from the CEO “I can see what you’re doing with your fingers at 100 meters,� is a statement with obvious intentions to decieve and confuse. "Seeing" is not a word I would associate with lidar, particularly real time. And a 30 hz lidar unit (did they mean 30 khz on their website?) "see's" nothing. Lidar gives you dots in space and their relative relation to each other and the lidar source, then those dots need to be interpreted to give the needed information. Maybe they are doing amazing interpretation, hard to tell from the website. But a 30 hz (or even a 30 khz) lidar gives very, very few data points, particularly from a moving car. So the system is interpreting something from that data to give information of some type, but this is nothing like seeing or vision as we would typically think of it. But it sounds good.
Not to be confused, the self driving car is on it's way and will dramatically change transportation, but that's not really a lidar issue.
And, more to the point of the thread, seeing thermals would change the sport, but would it lessen the fun in any way?

[[email protected]]

On Thursday, September 29, 2016 at 10:50:59 PM UTC-7, Craig Funston wrote:
> Motion of particles in the air

Oh, there is some capability in this regard, pollution, smoke, etc. Interesting, but probably not coming to glider cockpit any time soon :)

[[email protected]]

I personally think if we could actually see what the air is doing, we would quit flying. Makes a Class 5 river run look benign.

[Dave Nadler]

On Thursday, September 29, 2016 at 7:01:38 PM UTC-4, Craig Funston wrote:
> We're getting closer. A fist size LIDAR for $250...

Craig - There are lots of small low-cost Lidar units, but they are
for relatively short-range detection of a solid. I've played with
a hockey-puck size unit in an indoor-mapping application.
But, these are nNot long-range particle motion as already demonstrated
for remote thermal detection ;-)

See ya, Dave

[Steve Koerner]

On Friday, September 30, 2016 at 7:22:36 AM UTC-7, wrote:
> On Thursday, September 29, 2016 at 10:50:59 PM UTC-7, Craig Funston wrote:
> > Motion of particles in the air
>
> Not saying you are wrong, but what lidar unit can detect particles in the air? And from the CEO “I can see what you’re doing with your fingers at 100 meters,� is a statement with obvious intentions to decieve and confuse. "Seeing" is not a word I would associate with lidar, particularly real time. And a 30 hz lidar unit (did they mean 30 khz on their website?) "see's" nothing. Lidar gives you dots in space and their relative relation to each other and the lidar source, then those dots need to be interpreted to give the needed information. Maybe they are doing amazing interpretation, hard to tell from the website. But a 30 hz (or even a 30 khz) lidar gives very, very few data points, particularly from a moving car. So the system is interpreting something from that data to give information of some type, but this is nothing like seeing or vision as we would typically think of it. But it sounds good.
> Not to be confused, the self driving car is on it's way and will dramatically change transportation, but that's not really a lidar issue.
> And, more to the point of the thread, seeing thermals would change the sport, but would it lessen the fun in any way?

I interpret that what they are meaning by 30 Hz is a scene update rate of 30 Hz. That would actually seem much faster than needed for the glider application and would therefore offer a potential for integration over time to improve energy gathering. Remember also that the glider application has no need of resolving individual bugs. We're interested in net signal over a largish volume of space which again provides an integration opportunity over az, el and r.

[Dan Marotta]

Didn't the article say something like 100 or 200 meters range? Is that
enough to go through the OODA loop effectively? How wide an area will
be scanned? The wider the area, the sooner a thermal can be detected,
but the more power required to scan the area. How much power is
required vs. how much can the ship provide? Lower power means a
narrower field of view until you're basically blundering into thermals
as on a blue day (not considering observation of ground features).

I think it'll be a long time coming and, when it arrives, it will remove
all challenge from soaring thus further reducing the participants.

On 9/30/2016 9:05 AM, Steve Koerner wrote:
> On Friday, September 30, 2016 at 7:22:36 AM UTC-7, wrote:
>> On Thursday, September 29, 2016 at 10:50:59 PM UTC-7, Craig Funston wrote:
>>> Motion of particles in the air
>> Not saying you are wrong, but what lidar unit can detect particles in the air? And from the CEO “I can see what you’re doing with your fingers at 100 meters,� is a statement with obvious intentions to decieve and confuse. "Seeing" is not a word I would associate with lidar, particularly real time. And a 30 hz lidar unit (did they mean 30 khz on their website?) "see's" nothing. Lidar gives you dots in space and their relative relation to each other and the lidar source, then those dots need to be interpreted to give the needed information. Maybe they are doing amazing interpretation, hard to tell from the website. But a 30 hz (or even a 30 khz) lidar gives very, very few data points, particularly from a moving car. So the system is interpreting something from that data to give information of some type, but this is nothing like seeing or vision as we would typically think of it. But it sounds good.
>> Not to be confused, the self driving car is on it's way and will dramatically change transportation, but that's not really a lidar issue.
>> And, more to the point of the thread, seeing thermals would change the sport, but would it lessen the fun in any way?
> I interpret that what they are meaning by 30 Hz is a scene update rate of 30 Hz. That would actually seem much faster than needed for the glider application and would therefore offer a potential for integration over time to improve energy gathering. Remember also that the glider application has no need of resolving individual bugs. We're interested in net signal over a largish volume of space which again provides an integration opportunity over az, el and r.

--
Dan, 5J

[Jonathan St. Cloud]

Really, why is that? Not that this applies to you, but I have noticed that when new technology comes along so do the naysayers, GPS, Flarm, stealth Flarm, "entertainment system computers..." "This is the end of our sport"....

Having been an offshore sailor and glider pilot for many years, I can tell you that whatever you invent, it will still take a sharp mind and earned skills to guide an airplane or sailboat using just the energy in the atmosphere.

Personally, I want a Hud projected onto the canopy.


On Friday, September 30, 2016 at 6:33:01 AM UTC-7, wrote:
> On Friday, September 30, 2016 at 6:21:27 AM UTC-5, Tony wrote:
> > Awesome I can't wait!!
>
> Here comes the end of this world as we know it.

[[email protected]]

On Friday, September 30, 2016 at 12:17:59 PM UTC-7, Jonathan St. Cloud wrote:
> Personally, I want a Hud projected onto the canopy.

The view outside is too beautiful to mess it up with overlays :-) I want 3D audio and a big bright screen that covers the whole panel.

If a short range LIDAR can detect a thermal ahead, then initiating a pull up before entering the lift might prove advantageous. A bit longer range and it will be possible to make small course corrections while flying slowly in areas of lift.

5Z

[Steve Koerner]

Well, the point of my comment about the possibility of integration over time and space is that integration can accomplish a trade of resolution for increased range. So, I think there's basis for hoping the same hardware might give better range as a thermal detector. That said, bugs are pretty small and radar and lidar operate to an r^-4 law -- a tough nut to push against..

On Friday, September 30, 2016 at 9:52:33 AM UTC-7, Dan Marotta wrote:
> Didn't the article say something like 100 or 200 meters range? Is that
> enough to go through the OODA loop effectively? How wide an area will
> be scanned? The wider the area, the sooner a thermal can be detected,
> but the more power required to scan the area. How much power is
> required vs. how much can the ship provide? Lower power means a
> narrower field of view until you're basically blundering into thermals
> as on a blue day (not considering observation of ground features).
>
> I think it'll be a long time coming and, when it arrives, it will remove
> all challenge from soaring thus further reducing the participants.
>
> On 9/30/2016 9:05 AM, Steve Koerner wrote:
> > On Friday, September 30, 2016 at 7:22:36 AM UTC-7, wrote:
> >> On Thursday, September 29, 2016 at 10:50:59 PM UTC-7, Craig Funston wrote:
> >>> Motion of particles in the air
> >> Not saying you are wrong, but what lidar unit can detect particles in the air? And from the CEO “I can see what you’re doing with your fingers at 100 meters,� is a statement with obvious intentions to decieve and confuse. "Seeing" is not a word I would associate with lidar, particularly real time. And a 30 hz lidar unit (did they mean 30 khz on their website?) "see's" nothing. Lidar gives you dots in space and their relative relation to each other and the lidar source, then those dots need to be interpreted to give the needed information. Maybe they are doing amazing interpretation, hard to tell from the website. But a 30 hz (or even a 30 khz) lidar gives very, very few data points, particularly from a moving car. So the system is interpreting something from that data to give information of some type, but this is nothing like seeing or vision as we would typically think of it. But it sounds good.
> >> Not to be confused, the self driving car is on it's way and will dramatically change transportation, but that's not really a lidar issue.
> >> And, more to the point of the thread, seeing thermals would change the sport, but would it lessen the fun in any way?
> > I interpret that what they are meaning by 30 Hz is a scene update rate of 30 Hz. That would actually seem much faster than needed for the glider application and would therefore offer a potential for integration over time to improve energy gathering. Remember also that the glider application has no need of resolving individual bugs. We're interested in net signal over a largish volume of space which again provides an integration opportunity over az, el and r.
>
> --
> Dan, 5J

[HGXC[_4_]]

On Thursday, September 29, 2016 at 7:01:38 PM UTC-4, Craig Funston wrote:
> We're getting closer. A fist size LIDAR for $250 thanks to the push for self driving cars.
>
> https://www.technologyreview.com/s/602503/fist-sized-laser-scanner-to-make-autonomous-cars-less-ugly/?utm_campaign=internal&utm_medium=homepage&utm_source=top-stories_2&set=602506
>
> Cheers,
> 7Q

Back in the 80's hang gliding pilots had the "Thermal Snooper" Didn't take off (pun intended).

Dennis DC

[David Hirst]

On Saturday, October 1, 2016 at 6:23:06 PM UTC+13, Steve Koerner wrote:
> That said, bugs are pretty small and radar and lidar operate to an r^-4 law -- a tough nut to push against.

Yup. There's the problem. If you can scan the laser around, then the detection side is 'only' an r^-2 challenge but even so.. We already have lasers which are powerful enough but the big issue is detecting enough light from dust/bugs set against a bright background at a big enough distance (1-2km) and in a short enough time (100ms) to be useful. The people using LIDAR to map air currents around wind turbines use big-aperture (30 - 40cm) reflecting telescopes to capture enough incoming light. Wing pod, anyone?

Then imagine if every glider had them and imagine the cross-talk issues from all those lasers frantically scanning. Having said that, the vehicle lidar could be set up quite easily to detect big objects in a themal, like gliders circling within 1-2km and it could then give a warning on a HUD... oh, wait...

DH
TX

[firsys]

On Thursday, September 29, 2016 at 7:01:38 PM UTC-4, Craig Funston wrote:
> We're getting closer. A fist size LIDAR for $250 thanks to the push for self driving cars.
>
> https://www.technologyreview.com/s/602503/fist-sized-laser-scanner-to-make-autonomous-cars-less-ugly/?utm_campaign=internal&utm_medium=homepage&utm_source=top-stories_2&set=602506
>
> Cheers,
> 7Q

Boggs says " it is too hard to soar"!!!
Come on every ( well nearly)glider pilot can stay up all day,
on normal thermal soaring day, that is a day with enough convective
depth and not ever development.

I digress; In the 70s , I experimented with electric field detection
using nose and tail probes. Other researchers were doing this (eg Markson). I was able to observe a horizontal field across
a weak thermally created airmass boundary, by crossing and recrossing the otherwise invisible division. For XC soaring this is useless,because the problem of subtracting the large vertical atmospheric field from the weak horizontal field was close to impossible with 1970s technology.
These days there is enormous computing power and memory for calculations and 2D displays. Sensors for the vertical and horizontal fields, plus bank angle, could allow data accumulation allowing the wing tip sensors to show a display of horizontal fields( thermals are
usually positively charged). This could be a useful indication
for interthermal path selection.


John Firth an old no longer bold PIK 20E pilot.

[Mike the Strike]

I've seen enough soaring birds make a beeline for a thermal 1/4 mile away from them that I have to believe there is something visible, at least in some cases. Perhaps a creative optical solution might work if we find the right wavelength and polarization?

I also spent many happy years playing with the electric fields around clouds and sadly think they will be too chaotic around turbulent thermals to be any use.

Mike

[Jonathan St. Cloud]

A FLIR unit might offer a visual indication from much larger distance?

On Sunday, October 2, 2016 at 7:46:12 AM UTC-7, Mike the Strike wrote:
> I've seen enough soaring birds make a beeline for a thermal 1/4 mile away from them that I have to believe there is something visible, at least in some cases. Perhaps a creative optical solution might work if we find the right wavelength and polarization?
>
> I also spent many happy years playing with the electric fields around clouds and sadly think they will be too chaotic around turbulent thermals to be any use.
>
> Mike

[David Hirst]

On Monday, October 3, 2016 at 4:04:39 AM UTC+13, Jonathan St. Cloud wrote:
> A FLIR unit might offer a visual indication from much larger distance?
>
A few moons ago, I got chatting to a guy selling FLIR imaging systems at a trade show. I asked him about the problem of trying to see thermals, so we set an imager up to look at the hot air rising from a nearby vent and saw nothing (as he expected).
There's no problem seeing warm solid objects, since they consist of a lot of closely-packed warm emitters - high spatial density - but warm gas is so much more diffuse that any infrared 'brightness' just fades into the background, like a small amount of dye in a large volume of liquid. To do effective background subtraction, you need to know what the background is to begin with and on a typical thermal day this is the average temperature of the air which has high spatial variability.
I think birds can see all those rising insects, which makes the birds the best thermal indicators, if they can be bothered to fly where we want them to.

DH
TX

[Jonathan St. Cloud]

In the eighty's or nineties there was an article in "Soaring" by an U.S. Army Apache trainee, who noticed he could see raising thermal through his monocle. Not sure which sensor array was picking that up, but I thought it was the FLIR.

On Sunday, October 2, 2016 at 11:04:32 AM UTC-7, David Hirst wrote:
> On Monday, October 3, 2016 at 4:04:39 AM UTC+13, Jonathan St. Cloud wrote:
> > A FLIR unit might offer a visual indication from much larger distance?
> >
> A few moons ago, I got chatting to a guy selling FLIR imaging systems at a trade show. I asked him about the problem of trying to see thermals, so we set an imager up to look at the hot air rising from a nearby vent and saw nothing (as he expected).
> There's no problem seeing warm solid objects, since they consist of a lot of closely-packed warm emitters - high spatial density - but warm gas is so much more diffuse that any infrared 'brightness' just fades into the background, like a small amount of dye in a large volume of liquid. To do effective background subtraction, you need to know what the background is to begin with and on a typical thermal day this is the average temperature of the air which has high spatial variability.
> I think birds can see all those rising insects, which makes the birds the best thermal indicators, if they can be bothered to fly where we want them to.
>
> DH
> TX

[2G]

On Sunday, October 2, 2016 at 8:04:39 AM UTC-7, Jonathan St. Cloud wrote:
> A FLIR unit might offer a visual indication from much larger distance?
>
> On Sunday, October 2, 2016 at 7:46:12 AM UTC-7, Mike the Strike wrote:
> > I've seen enough soaring birds make a beeline for a thermal 1/4 mile away from them that I have to believe there is something visible, at least in some cases. Perhaps a creative optical solution might work if we find the right wavelength and polarization?
> >
> > I also spent many happy years playing with the electric fields around clouds and sadly think they will be too chaotic around turbulent thermals to be any use.
> >
> > Mike

A helicopter pilot flying in the first Iraq war reported on seeing thermals clearly visible in daylight using his night vision FLIR. Kind of tough to thermal a chopper, however.

Tom

[krasw]

Weather radar can see insects in thermals, if adjusted for weak echos. No need to carry radar on board, just form a composite image from ground based radars and link image data to cockpit. Technology exists already.

[Martin Gregorie[_5_]]

On Sun, 02 Oct 2016 12:20:59 -0700, krasw wrote:

> Weather radar can see insects in thermals, if adjusted for weak echos.
> No need to carry radar on board, just form a composite image from ground
> based radars and link image data to cockpit. Technology exists already.

When Maynard Hill was working for NACA/NASA (at Langley I think) a new
radar they'd developed showed mysterious woolly blobs over a nearby
field. He had an idea what they were, refused to say more and went home,
grabbed an RC sailplane and took it plus an RT set out to the field,
launched and had the crew talk his model into the blob. It went up,
proving the radar was spotting thermals. IIRC this story appeared on the
Academy of Model Aeronautics's magazine, Model Aviation. The AMA is the
governing body for American model aviation.

Do any of you know more about this? Esp the frequency the radar used and
how/why it detected thermals.

Maynard Hill was a well-known American RC pilot and record breaker.
He set out to break records because he found that more fun than competing
in any type of organised competition.
https://www.modelaircraft.org/mag/mhill/hillindex.htm

Among other feats he was the first to fly a model aircraft across the
Atlantic. That was done with his self designed and built autonomous
model. To qualify as a model its all-up weight (including fuel) at launch
had to be 5kg or less.

There's an article about his Trans Atlantic Model here:
https://en.wikipedia.org/wiki/The_Spirit_of_Butts%27_Farm



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Fraser Wilson[_2_]]

Systems which transmit power such lidars need to throw out large amounts
of energy to get even tiny detectable returns. Not good for battery based
power supplies. Batteries are not really that power dense and I'm no where

near as confident that we will see the really big step forward that most
tech
pundits are predicting.

Thermal imaging needs a fair bit of power to get a reasonable temperature
difference to the warm air your trying to detect. Again this is too power
hunger for batteries.

Even if you could realise these they both suffer from the basic flaw, in
that
they tell what's happening 10k down track while you're 10+minutes away
from actually getting to it. By the time you arrive it' frequently
changed.

My vision of the next step in remote thermal detection follows a different
tac.
Computer CPU processing will certainly continue its quite staggering
increase
in capacity. So I reckon we could see a super high fidelity RASP. This
would
be constant refining its numerical predictions based on real time
observations
from both you flight and others via flarm. It would also use historical
"big
data" previously collected from hundreds if not thousands of flights in the

same area to further tune the predictions with likely thermal nucleation
locations. Now we would have a systems which is actively modelling the
atmosphere in a strip say 50k down track and 10 k wide, in real time. The
really intriguing aspect of this is that it's producing predictions both in
terms
of what thermals will be further down the intended track and what strength

they will be when you actually arrive.

An imagination can be a scary thing.

Fraser

[Jonathan St. Cloud]

I have many times used ridge and thermal lift hime flying a helicopter.

On Sunday, October 2, 2016 at 12:19:12 PM UTC-7, 2G wrote:

> A helicopter pilot flying in the first Iraq war reported on seeing thermals clearly visible in daylight using his night vision FLIR. Kind of tough to thermal a chopper, however.
>
> Tom

[krasw]

sunnuntai 2. lokakuuta 2016 22.49.17 UTC+3 Martin Gregorie kirjoitti:
>
> Do any of you know more about this? Esp the frequency the radar used and
> how/why it detected thermals.

Insects are sucked to thermals from close to ground. These are roughly same size as rain or snow coming down from clouds, so they are visible in weather radar images accordingly, as are birds and larger objects. I believe weather radars operate in centimeter scale wavelength.

[Tango Whisky]

Le dimanche 2 octobre 2016 20:57:45 UTC+2, Jonathan St. Cloud a écritÂ*:
> In the eighty's or nineties there was an article in "Soaring" by an U.S. Army Apache trainee, who noticed he could see raising thermal through his monocle. Not sure which sensor array was picking that up, but I thought it was the FLIR.
>
> On Sunday, October 2, 2016 at 11:04:32 AM UTC-7, David Hirst wrote:
> > On Monday, October 3, 2016 at 4:04:39 AM UTC+13, Jonathan St. Cloud wrote:
> > > A FLIR unit might offer a visual indication from much larger distance?
> > >
> > A few moons ago, I got chatting to a guy selling FLIR imaging systems at a trade show. I asked him about the problem of trying to see thermals, so we set an imager up to look at the hot air rising from a nearby vent and saw nothing (as he expected).
> > There's no problem seeing warm solid objects, since they consist of a lot of closely-packed warm emitters - high spatial density - but warm gas is so much more diffuse that any infrared 'brightness' just fades into the background, like a small amount of dye in a large volume of liquid. To do effective background subtraction, you need to know what the background is to begin with and on a typical thermal day this is the average temperature of the air which has high spatial variability.
> > I think birds can see all those rising insects, which makes the birds the best thermal indicators, if they can be bothered to fly where we want them to.
> >
> > DH
> > TX

You cannot detect hot air from a distance by any infrared detector (and FLIR is infrared imaging). Obviously, your sales guy wasn't up to speed with physics.

Hot air emits infrard radiation. However, as emission and absorption coefficients are the same thing, the air inbetween the thermal and your FLIR will absorb all of this radiation, and you won't see anything on your imager. That's how physics works. The stories about people having seen infrared images of thermals are just urband legends.

Bert (who has been developing infrared sensors and systems for more than 15 years)

[ND]

A HUD would be cool, but don't you think it would be a bit of a problem, or annoyance, keeping track of the towplane on tow, finding oncoming traffic, especially on the ridge, and obstructing part of your view in general? i mean it's a cool idea, but is it practical?

On Friday, September 30, 2016 at 3:17:59 PM UTC-4, Jonathan St. Cloud wrote:
> Really, why is that? Not that this applies to you, but I have noticed that when new technology comes along so do the naysayers, GPS, Flarm, stealth Flarm, "entertainment system computers..." "This is the end of our sport".....
>
> Having been an offshore sailor and glider pilot for many years, I can tell you that whatever you invent, it will still take a sharp mind and earned skills to guide an airplane or sailboat using just the energy in the atmosphere.
>
> Personally, I want a Hud projected onto the canopy.
>
>
> On Friday, September 30, 2016 at 6:33:01 AM UTC-7, wrote:
> > On Friday, September 30, 2016 at 6:21:27 AM UTC-5, Tony wrote:
> > > Awesome I can't wait!!
> >
> > Here comes the end of this world as we know i

[Loye Hilton[_2_]]

At 13:03 03 October 2016, Tango Whisky wrote:
>Le dimanche 2 octobre 2016 20:57:45 UTC+2, Jonathan St. Cloud
a =C3=A9crit=
>=C2=A0:
>> In the eighty's or nineties there was an article in "Soaring" by
an U.S.
>=
>Army Apache trainee, who noticed he could see raising thermal
through his
>m=
>onocle. Not sure which sensor array was picking that up, but I
thought it
>=
>was the FLIR.
>>=20
>> On Sunday, October 2, 2016 at 11:04:32 AM UTC-7, David
Hirst wrote:
>> > On Monday, October 3, 2016 at 4:04:39 AM UTC+13,
Jonathan St. Cloud
>wro=
>te:
>> > > A FLIR unit might offer a visual indication from much larger
>distance=
>? =20
>> > >
>> > A few moons ago, I got chatting to a guy selling FLIR imaging
systems
>a=
>t a trade show. I asked him about the problem of trying to see
thermals,
>s=
>o we set an imager up to look at the hot air rising from a nearby
vent and
>=
>saw nothing (as he expected). =20
>> > There's no problem seeing warm solid objects, since they
consist of a
>l=
>ot of closely-packed warm emitters - high spatial density - but
warm gas
>is=
> so much more diffuse that any infrared 'brightness' just fades
into the
>ba=
>ckground, like a small amount of dye in a large volume of liquid.
To do
>ef=
>fective background subtraction, you need to know what the
background is to
>=
>begin with and on a typical thermal day this is the average
temperature of
>=
>the air which has high spatial variability.
>> > I think birds can see all those rising insects, which makes the
birds
>t=
>he best thermal indicators, if they can be bothered to fly where we
want
>th=
>em to.
>> >=20
>> > DH
>> > TX
>
>You cannot detect hot air from a distance by any infrared detector
(and
>FLI=
>R is infrared imaging). Obviously, your sales guy wasn't up to
speed with
>p=
>hysics.
>
>Hot air emits infrard radiation. However, as emission and
absorption
>coeffi=
>cients are the same thing, the air inbetween the thermal and your
FLIR
>will=
> absorb all of this radiation, and you won't see anything on your
imager.
>T=
>hat's how physics works. The stories about people having seen
infrared
>imag=
>es of thermals are just urband legends.
>
>Bert (who has been developing infrared sensors and systems for
more than
>15=
> years)
>In the early 70's Wally Scott was flying a OD Green 1-34 ? for MIT
and they were trying to see dust particles in thermals in west texas.
with todays tech. it may be possible.any body else remember this.

[kirk.stant]

On Monday, October 3, 2016 at 8:12:38 AM UTC-5, ND wrote:
> A HUD would be cool, but don't you think it would be a bit of a problem, or annoyance, keeping track of the towplane on tow, finding oncoming traffic, especially on the ridge, and obstructing part of your view in general? i mean it's a cool idea, but is it practical?

It's really not a HUD that you want, it's a HMD (Helmet Mounted Display) - now being used in most fighters (look up JHMCS). A HUD only covers a small piece of sky in front of you - it's really just a fancy gunsight. A HMD is more like a super Google Glass - puts the appropriate data in front of your eyes wherever you are looking. So for example, in a hypothetical glider-optimized BHMD (Bucket Hat Mounted Display), you would see airspeed, altitude, vario, heading, a pointer to the next turnpoint, reachable airfields, FLARM and ADS-B aircraft, etc; essentially you never have to look down into the cockpit.

With the head tracking tech used for VR, it's not really too far fetched - but we may need bigger canopies to fit over our helmets!

Kirk
66

[Mike the Strike]

>
> Bert (who has been developing infrared sensors and systems for more than 15 years)

Yes, and the air in thermals isn't even very hot compared to the surrounding air - perhaps just fractions of a degree. The only significant difference the thermal has that you might be able to detect is its upward motion. Entrained dust or insects might work sometimes. I had a thermal full of corn stalks one time - very easy to see!

Mike

[Tony[_5_]]

Corn Devils. Very common in the spring and fall in the Midwest :)

[krasw]

While seeing thermals with IR camera is close to impossible, you can at least see hot spots on the ground:

http://www.paragliding.de/en/thermiksuche-waermebildkamera/

Apparently works only close range.

[Soartech]

This has been one of my favorite subject since the early 1980's.
Everyone's comments have been great and useful!
Let's review some of the possiblites.
Because thermals are equated with heat the first thing most people jump to is infrared. Mike the Strike has pointed out that thermals only have a fraction of a degree difference from surrounding air. TW and David Hurst have also pointed out that air is a very poor radiator of infrared and is invisible to commercial thermal cameras. This is all true.
However I would ask Tom (2G) to please tell us where he heard or read of the military night vision system user seeing thermals over Iraq. That might be a case of intense desert thermals near the ground. Scientific aircraft monitoring has shown that thermals often are cooler than the local air above halfway to cloudbase.
I would also like to ask Jonathan St.Cloud to dig up the reference he had about an Apache trainee. A search for "Apache" in the Soaring mag database does not find anything useful.
Next subject is LIDAR. Lidar is laser radar. It has been shown to be able to detect thermals since the early 1970's. It does this by sensing backscatter from dust and pollen in the air. Very clean air is harder to see. See articles by Eloranta (University of Wisconsin) and many others. Problems are many: the required laser power is large, 100K Watts+ in the pulse, the light-gathering optics are physically large (think 8 inch diameter telescope)as pointed out by someone here, and the cost is huge. You can get a nice little laser that has the required power and is small enough but it costs $75K. Then add the complex electronics that generate and detect picosecond pulses and you see the real-world problems that make this a difficult instrument to cram into a sailplane. It can be done if you have lots of money to spend.
Next possibilty is RADAR. Most of the radar schemes detect bugs.(Raptors most likely see bugs in the air with their superior vision.) No bugs today and your expensive, bulky radar won't work today. A better choice is something called FM-CW radar. This has been shown to work at less power by detection of the moisture differences between the thermal edge and the surrounding air. This scheme may not work in very dry environnments. The amount of power required is in the hundreds of Watts. The antenna is likely to present a very draggy problem.
I won't bore you with other possiblites but there are some that have not been adequetly explored. I'm working on a few. Technology gets us closer every year. It will happen eventually. This will not make soaring boring at all. It's just another useful tool to help you. Probably the first thing to come out will be a short range solution. Many times you can see a cloud, get to it and find nothing. Then you explore all areas under the cloud and on one corner there is lift. A 1000 foot range detector would help greatly in this situation.

[Jonathan St. Cloud]

Soaring June 1993, article named "Chasing Ghosts". The author said he could see thermals during the day while, training in "The Bag", so he was using the monocle with PNVS. Not sure what PNVS is but it sounds like a combo of night vision and IR?

On Wednesday, October 5, 2016 at 11:27:30 AM UTC-7, Soartech wrote:

> I would also like to ask Jonathan St.Cloud to dig up the reference he had about an Apache trainee.

[Jonathan St. Cloud]

Did a bit of research http://www.lockheedmartin.com/us/products/Arrowhead.html very disappointing to find that this system is optimized for target detection, not thermal detection, although according to the June, 1993, article in Soaring it can detect thermals, but it did not say at what distance. Maybe an Apache pilot is on RAS?

[John Cochrane[_3_]]

I'm also a fan.

No, it won't turn the sport into a video game, any more than vario and GPS did. Flying -- and racing -- airplanes without engines will always be a challenge.

It will be the single greatest increase in performance since fiberglass (also loudly predicted to kill the sport).

Thermal detectors will end start gate roulette, gaggling and leeching and team flying. There is no need to wait for other gliders if you can detect thermals on your own.

Thermal detectors will also enhance safety. Finding that last thermal might help an outlining. More importantly, if you really know there are NO thermals out there, you get busy with the business of landing!

Even 200 feet will be of immense use. Really, all the great team flyers are getting for their efforts is sampling air 200 feet away. Imagine if you had two guys 200 feet ahead one on each side 45 degrees -- any of us could win the worlds. Think of how many great contests have been won or lost by missing one thermal by a few hundred feet.

Contrary to earlier posts, so what if it doesn't work all the time! Give me a thermal detector that works 200 feet out 1/4 of the time and I can win any contest!

More physical principles:

Doppler Lidar, of course. Somewhere I saw the military is working on a portable lidar based system that detects crosswinds to make shooting more accurate. That's just what we need.

Non-doppler lidar. Thermals have more dust in them than surrounding air. See the concentration of dust, bugs, etc. and you know where the thermal is.

Radar, as mentioned. Tuned to bugs, birds, moisture gradients, etc.

Passive radar. Radar needs power. But why shine your own light when the FAA does it for you? Monitoring the primary and return echoes you should be able to see what's out ahead with no primary source.

Shimmer. As reported here, Boeing was working on a system to process visual images for shimmer to see clear air turbulence. Set up video camera to take pictures every second or two, software to compare the images, and enhance shimmer induced turbulence, thus seeing thermal structure.

More optical. Process optical images to see birds! (and other gliders) Again, take two optical images a few seconds apart, signal process to correct for glider motion, then show anything that's moving. (The last two, since they only involve taking pictures, would be arguably legal under US rules too. SHHH. )

Humidity. Infra-red cameras tuned to moisture frequencies, like the satellite moisture channel. Thermals are more moist than the surrounding environment.

You don't need to see motion, you only need to see structure of the air and you can deduce motion.

Bring it on!

John Cochrane (Flame suit on)

[Charlie M. (UH & 002 owner/pilot)]

Sorta like A-10 pilots didn't have night vision, but, they looked at the FLIR display from missles as an alternate. Crude, but it worked.

Hey, use what ya got........

[Craig Funston]

On Wednesday, October 5, 2016 at 2:04:16 PM UTC-7, John Cochrane wrote:
> I'm also a fan.
>
> No, it won't turn the sport into a video game, any more than vario and GPS did. Flying -- and racing -- airplanes without engines will always be a challenge.
>
> It will be the single greatest increase in performance since fiberglass (also loudly predicted to kill the sport).
>
> Thermal detectors will end start gate roulette, gaggling and leeching and team flying. There is no need to wait for other gliders if you can detect thermals on your own.
>
> Thermal detectors will also enhance safety. Finding that last thermal might help an outlining. More importantly, if you really know there are NO thermals out there, you get busy with the business of landing!
>
> Even 200 feet will be of immense use. Really, all the great team flyers are getting for their efforts is sampling air 200 feet away. Imagine if you had two guys 200 feet ahead one on each side 45 degrees -- any of us could win the worlds. Think of how many great contests have been won or lost by missing one thermal by a few hundred feet.
>
> Contrary to earlier posts, so what if it doesn't work all the time! Give me a thermal detector that works 200 feet out 1/4 of the time and I can win any contest!
>
> More physical principles:
>
> Doppler Lidar, of course. Somewhere I saw the military is working on a portable lidar based system that detects crosswinds to make shooting more accurate. That's just what we need.
>
> Non-doppler lidar. Thermals have more dust in them than surrounding air. See the concentration of dust, bugs, etc. and you know where the thermal is..
>
> Radar, as mentioned. Tuned to bugs, birds, moisture gradients, etc.
>
> Passive radar. Radar needs power. But why shine your own light when the FAA does it for you? Monitoring the primary and return echoes you should be able to see what's out ahead with no primary source.
>
> Shimmer. As reported here, Boeing was working on a system to process visual images for shimmer to see clear air turbulence. Set up video camera to take pictures every second or two, software to compare the images, and enhance shimmer induced turbulence, thus seeing thermal structure.
>
> More optical. Process optical images to see birds! (and other gliders) Again, take two optical images a few seconds apart, signal process to correct for glider motion, then show anything that's moving. (The last two, since they only involve taking pictures, would be arguably legal under US rules too. SHHH. )
>
> Humidity. Infra-red cameras tuned to moisture frequencies, like the satellite moisture channel. Thermals are more moist than the surrounding environment.
>
> You don't need to see motion, you only need to see structure of the air and you can deduce motion.
>
> Bring it on!
>
> John Cochrane (Flame suit on)

John, I completely agree. Many of our most important scientific advances are based on improving our ability to "see" the world around us. Telescopes, microscopes, radar, the list goes on and on. I'm eagerly awaiting improvements in thermal detection for sailplanes. I don't see it taking away the fun or the magic. There's still lots to explore.

Craig

[WB]

>
> Shimmer. As reported here, Boeing was working on a system to process visual images for shimmer to see clear air turbulence. Set up video camera to take pictures every second or two, software to compare the images, and enhance shimmer induced turbulence, thus seeing thermal structure.
>
> More optical. Process optical images to see birds! (and other gliders) Again, take two optical images a few seconds apart, signal process to correct for glider motion, then show anything that's moving. (The last two, since they only involve taking pictures, would be arguably legal under US rules too. SHHH. )
>
>
> John Cochrane (Flame suit on)


The possibility of using machine vision, as John mentions above, is indeed intriguing from both the lift sensing AND the anti-collision angles. Of course, such a device would have it's tactical uses in soaring contests, not that anyone cares about THAT. What I like is that machine vision collision avoidance, being passive, would not depend on everyone else installing equipment. Ideally, it would point out all traffic, including birds. Seems to me that UAV's are a huge and growing market for that sort of tech. Sort of surprising then that I have seen only one machine vision anti-collision system being marketed.

I have tried posting about this a couple of times on RAS, mainly to see if anyone here knows anything about new developments along this line, so please do comment if you have seen or heard anything pertinent.

Wallace Berry (currently working with engineers to apply machine vision to chicken farming)

[Soartech]

Re: machine vision. I've envisioned a system similar to what hawks might use. A video camera with telescope in the cockpit is connected to a computer and to a very sensitive vario. The idea is for the camera to spot bugs, leaves, etc. in the air and then determine their vertical motion and approximate rate. Since we are a moving platform we must subtract out the motion of the sailplane in the vertical to obtain a true picture of what the remote objects are doing. If you've ever looked at distant bugs with a powerful telescope you know the problems that would occur with this scheme. But it could be done.

[WB]

Link to a DARPA machine vision system for aviation collision avoidance:

http://www.darpa.mil/news-events/2016-04-05a

Link to a system apparently already on the market for UAV's:

http://www.sara.com/isr/uav_payloads/oca.html

[Dan Marotta]

One of those optical systems mounted on the glare shield would be great
for collision avoidance assuming a decent user interface, however
there's no current way to look out behind you for overtaking aircraft.

On 10/10/2016 9:27 AM, WB wrote:
> Link to a DARPA machine vision system for aviation collision avoidance:
>
> http://www.darpa.mil/news-events/2016-04-05a
>
> Link to a system apparently already on the market for UAV's:
>
> http://www.sara.com/isr/uav_payloads/oca.html

--
Dan, 5J

[WB]

On Monday, October 10, 2016 at 11:30:46 AM UTC-5, Dan Marotta wrote:
> One of those optical systems mounted on the glare shield would be great
> for collision avoidance assuming a decent user interface, however
> there's no current way to look out behind you for overtaking aircraft.
>
> On 10/10/2016 9:27 AM, WB wrote:
> > Link to a DARPA machine vision system for aviation collision avoidance:
> >
> > http://www.darpa.mil/news-events/2016-04-05a
> >
> > Link to a system apparently already on the market for UAV's:
> >
> > http://www.sara.com/isr/uav_payloads/oca.html
>
> --
> Dan, 5J

Yeah, it would take another unit or at least another set of sensor cameras to cover the rear. The cameras on the SARA unit look pretty small so should be possible to fit rearward facing cameras in small fairings. Maybe into something like the control horn fairings on the wings.