When are thermals not circular and do thermal helpers assume thatthey are? [Archive]

jfitch

July 30th 13, 01:54 AM

On Monday, July 29, 2013 5:14:01 PM UTC-7, Tim Taylor wrote:
> On Monday, July 29, 2013 10:00:11 AM UTC-6, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
>
>
> Most of the "Thermal Assistants" will assume circular but give a reasonable idea of the varied strength all the way around. WinPilot is the best I have used, SeeYou Mobile is about the worst. You can choose to adjust position from the values but in general seat feel will tell you more most of the time. I have not seen a nice circular and even strength thermal all the way around in months. Last Friday every thermal had multiple cores and strong centers about 50 feet across. They would also increase right until they dropped off a cliff. Level out into the stronger lift and it would increase through about 10 knots and then drop to sink instantly. I felt like a needed to go back to basic flight training again.

+1 on Winpilot's thermal assistant being markedly better than the others. SYM useless, XCSoar marginal on its best days.

Thermals may not be circular, but your glider flies in a pretty good approximation of a circle. So the cylindrical graph depicted in Winpilot is all the information you can really use. XCSoar's polar graph might fool you into thinking that is the shape of the lift - but it is a polar graph of strength around a fixed radius circle, not a map of the thermal. Oh yeah they are different!

Tim were you flying the Tahoe/Minden/Truckee area? Last weekend the thermals were diabolical.

Richard[_9_]

July 30th 13, 02:44 AM

On Monday, July 29, 2013 9:00:11 AM UTC-7, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

I find that the SeeYou Thermal assistant works very well. Why don't you think it works. The manual on page 30-31 of the Oudie manual explains how it works

Richard
www.craggyaero.com

Tim Taylor

July 30th 13, 03:43 AM

On Monday, July 29, 2013 7:44:44 PM UTC-6, Richard wrote:
> On Monday, July 29, 2013 9:00:11 AM UTC-7, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
>
>
> I find that the SeeYou Thermal assistant works very well. Why don't you think it works. The manual on page 30-31 of the Oudie manual explains how it works
>
>
>
> Richard
>
> www.craggyaero.com

Jon, I was flying in Northern UT, Idaho and Wyoming but it sounds like the same air mass. I did get a god OLC score on 7/26 but it had nothing to do with my thermalling ability.

Richard,

SYM just doesn't seem to work well. I have read the manuals and tried many different settings. Here are a few observations:

1. The interface is not as intuitive and easy to understand as WP. I have tried both type of displays and neither is great. I use the circle system most of the time now. I wish the circle diameter was constant rather than relative to each other. WP graphic is so much better on a 1 to 10 scale the WP is a 9 and the SYM is about a 4.

2. The timing appear to be off by about 30 or more degrees with SYM. Very often if you open up in the direction of what should be stronger it is not correct.

3. The timing of it turning on and off is random at best and frustrating at worst. It usually takes two or three full turns to come on and sometimes longer. Those first few turns are when you need it the most. WP would come on about 90 to 120 degrees into a turn. SYM tends to come on when you are finally cored and don't need it as much. It also comes and goes randomly when still in a thermal.

4. You can not toggle it on and off easily. With WP I had a button to push to turn it off if I was thermalling and wanted to see other information. With SYM I added the button to the menu bar but is does not work well. It will turn off the Thermal circles graphic but leave you in the thermal window.

5. SYM lacks the thermal strength versus time graph. This is extremely useful to determine how you are doing over time and the shape of the curve helps to determine if you need to adjust the circle.

6. In weak conditions where you are looking for very small amounts of lift SYM is correct on the direction about 50% of the time, WP was more like 90%..

SYM has many strengths but the TM is not one of them. I wish they would listen to users and improve it to something close to what WP has. Just offer a WP like TM page for those that want it. On the flipside I wish WP would listen to users and fix the known issues rather than chasing iPhone apps that can not be seen in a cockpit. Too bad neither seem to care about making the best possible product. No real hard things to fix for either company..

TT

Tim Taylor

July 30th 13, 03:48 AM

On Monday, July 29, 2013 7:44:44 PM UTC-6, Richard wrote:
> On Monday, July 29, 2013 9:00:11 AM UTC-7, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
>
>
> I find that the SeeYou Thermal assistant works very well. Why don't you think it works. The manual on page 30-31 of the Oudie manual explains how it works
>
>
>
> Richard
>
> www.craggyaero.com

Jon, I was flying in Northern UT, Idaho and Wyoming but it sounds like the same air mass. I did get a good OLC score on 7/26 but it had nothing to do with my thermalling ability.

Richard,

SYM just doesn't seem to work well. I have read the manuals and tried many different settings. Here are a few observations:

1. The interface is not as intuitive and easy to understand as WP. I have tried both type of displays in STM and neither is great. I use the circle system most of the time now. I wish the circle diameter was constant rather than relative to each other. WP graphic is so much better on a 1 to 10 scale the WP is a 9 and the SYM is about a 4.

2. The timing appear to be off by about 30 or more degrees with SYM. Very often if you open up in the direction of what should be stronger it is not correct.

3. The timing of it turning on and off is random at best and frustrating at worst. It usually takes two or three full turns to come on and sometimes longer. Those first few turns are when you need it the most. WP would come on about 90 to 120 degrees into a turn. SYM tends to come on when you are finally cored and don't need it as much. It also comes and goes randomly when still in a thermal.

4. You can not toggle it on and off easily. With WP I had a button to push to turn it off if I was thermalling and wanted to see other information. With SYM I added the button to the menu bar but is does not work well. It will turn off the Thermal circles graphic but leave you in the thermal window.

5. SYM lacks the thermal strength versus time graph. This is extremely useful to determine how you are doing over time and the shape of the curve helps to determine if you need to adjust the circle.

6. In weak conditions where you are looking for very small amounts of lift SYM is correct on the direction about 50% of the time, WP was more like 90%..

SYM has many strengths but the Thermal Assistant is not one of them. I wish they would listen to users and improve it to something close to what WP has. Just offer a WP like TM page for those that want it. On the flipside I wish WP would listen to users and fix the known issues rather than chasing iPhone apps that can not be seen in a cockpit. Too bad neither seem to care about making the best possible product. No real hard things to fix for either company.

TT

jfitch

July 30th 13, 06:42 AM

On Monday, July 29, 2013 7:48:05 PM UTC-7, Tim Taylor wrote:
> On Monday, July 29, 2013 7:44:44 PM UTC-6, Richard wrote:
>
> > On Monday, July 29, 2013 9:00:11 AM UTC-7, son_of_flubber wrote:
>
> >
>
> > > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
> >
>
> >
>
> >
>
> > I find that the SeeYou Thermal assistant works very well. Why don't you think it works. The manual on page 30-31 of the Oudie manual explains how it works
>
> >
>
> >
>
> >
>
> > Richard
>
> >
>
> > www.craggyaero.com
>
>
>
> Jon, I was flying in Northern UT, Idaho and Wyoming but it sounds like the same air mass. I did get a good OLC score on 7/26 but it had nothing to do with my thermalling ability.
>
>
>
> Richard,
>
>
>
> SYM just doesn't seem to work well. I have read the manuals and tried many different settings. Here are a few observations:
>
>
>
> 1. The interface is not as intuitive and easy to understand as WP. I have tried both type of displays in STM and neither is great. I use the circle system most of the time now. I wish the circle diameter was constant rather than relative to each other. WP graphic is so much better on a 1 to 10 scale the WP is a 9 and the SYM is about a 4.
>
>
>
> 2. The timing appear to be off by about 30 or more degrees with SYM. Very often if you open up in the direction of what should be stronger it is not correct.
>
>
>
> 3. The timing of it turning on and off is random at best and frustrating at worst. It usually takes two or three full turns to come on and sometimes longer. Those first few turns are when you need it the most. WP would come on about 90 to 120 degrees into a turn. SYM tends to come on when you are finally cored and don't need it as much. It also comes and goes randomly when still in a thermal.
>
>
>
> 4. You can not toggle it on and off easily. With WP I had a button to push to turn it off if I was thermalling and wanted to see other information. With SYM I added the button to the menu bar but is does not work well. It will turn off the Thermal circles graphic but leave you in the thermal window.
>
>
>
> 5. SYM lacks the thermal strength versus time graph. This is extremely useful to determine how you are doing over time and the shape of the curve helps to determine if you need to adjust the circle.
>
>
>
> 6. In weak conditions where you are looking for very small amounts of lift SYM is correct on the direction about 50% of the time, WP was more like 90%.
>
>
>
> SYM has many strengths but the Thermal Assistant is not one of them. I wish they would listen to users and improve it to something close to what WP has. Just offer a WP like TM page for those that want it. On the flipside I wish WP would listen to users and fix the known issues rather than chasing iPhone apps that can not be seen in a cockpit. Too bad neither seem to care about making the best possible product. No real hard things to fix for either company.
>
>
>
> TT

Pretty much what he said. I would add that the depiction of all Flarm contacts, with associated information on the Thermal Assistant page is at the very least entertaining and very good for situational awareness.

waremark

July 30th 13, 08:51 AM

You guys who find the WP thermal assistant so much better than others - are you running them on the same hardware with the same inputs? I hope you are not basing any comments on an Oudie using its internal GPS because it is known that the info from the internal GPS is not good enough for a thermal assistant.

glidergreg

July 30th 13, 01:19 PM

On Monday, July 29, 2013 11:00:11 AM UTC-5, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

SYM user hint.

In thermal display,tap the screen once to exit it.

son_of_flubber

July 30th 13, 02:34 PM

On Monday, July 29, 2013 12:00:11 PM UTC-4, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

(Am I crazy or)does a stream of wind coming through a mountain pass often interact with a series of ground generated thermals to produce a long line of lift (bordered by a parallel line of sink.) Circling just divides my time between the line of lift and the line of sink. What about flying a rectangle so that the downwind leg is not in sink? Tight turns to reverse direction at either end of the line of lift? Other strategies?

Papa3[_2_]

July 30th 13, 02:49 PM

One of the pundits in our club has a simple saying. It's "God's Air", so lift is where you find it. Bubbles, pulses, streams, multiple cores, lines... you name it. Like TT mentioned above, there are some days when you find yourself screaming out loud in the cockpit wondering where the *#$%! 10kt core just went or the dreaded 6kts up and 7kts down "thermal". The circle is as good a model as any to start, but the re-centering strategy and the need constantly be executing that strategy is the real key.

FWIW, my LS4 was a glider that let you get away with "dynamically thermalling." You could haul back on the stick, slam the rudder, and sort of pirouette into a core without degrading climb performance. My LS8 is a little less forgiving of large airspeed/pitch excursions; my friends tell me the ASW-24 is even less forgiving. A lot depends upon what your particular glider can/can't do. I make it a habit to fly one of the club's 1-26s a couple of times each year, just to remember how much fun it can be to flail around in broken lift with a low wingloading glider. I think the "model" you use has to take into account flying styles and the glider as well.

P3

On Tuesday, July 30, 2013 9:34:16 AM UTC-4, son_of_flubber wrote:
> On Monday, July 29, 2013 12:00:11 PM UTC-4, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
> (Am I crazy or)does a stream of wind coming through a mountain pass often interact with a series of ground generated thermals to produce a long line of lift (bordered by a parallel line of sink.) Circling just divides my time between the line of lift and the line of sink. What about flying a rectangle so that the downwind leg is not in sink? Tight turns to reverse direction at either end of the line of lift?

Luke Szczepaniak

July 30th 13, 02:52 PM

On 07/30/2013 9:34 AM, son_of_flubber wrote:
> Other strategies?

There is only one right answer; fly in the lift, avoid the sink. Do
whatever is necessary to keep it that way BUT avoid loss due to
unnecessary control movements /attitude changes. Avoiding erratic
changes also minimizes risk of a mid-air if you are flying with other
aircraft in the same thermal.

Luke

6PK

July 30th 13, 03:19 PM

Dan Marotta

July 30th 13, 03:59 PM

I think you've hit it jfitch. I didn't consider the polar graph.

"jfitch" > wrote in message
...
On Monday, July 29, 2013 5:14:01 PM UTC-7, Tim Taylor wrote:
> On Monday, July 29, 2013 10:00:11 AM UTC-6, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a
> > flatland phenomena.
>
>
>
> Most of the "Thermal Assistants" will assume circular but give a
> reasonable idea of the varied strength all the way around. WinPilot is the
> best I have used, SeeYou Mobile is about the worst. You can choose to
> adjust position from the values but in general seat feel will tell you
> more most of the time. I have not seen a nice circular and even strength
> thermal all the way around in months. Last Friday every thermal had
> multiple cores and strong centers about 50 feet across. They would also
> increase right until they dropped off a cliff. Level out into the
> stronger lift and it would increase through about 10 knots and then drop
> to sink instantly. I felt like a needed to go back to basic flight
> training again.

+1 on Winpilot's thermal assistant being markedly better than the others.
SYM useless, XCSoar marginal on its best days.

Thermals may not be circular, but your glider flies in a pretty good
approximation of a circle. So the cylindrical graph depicted in Winpilot is
all the information you can really use. XCSoar's polar graph might fool you
into thinking that is the shape of the lift - but it is a polar graph of
strength around a fixed radius circle, not a map of the thermal. Oh yeah
they are different!

Tim were you flying the Tahoe/Minden/Truckee area? Last weekend the thermals
were diabolical.

Dan Marotta

July 30th 13, 04:06 PM

I'll jump in here before Max does. XCSoar is open source. You can download
all of the source code and study the algorithms yourself.

I also have to ask: Do you really *need* a thermal assistant? I can fly
with the pitot tube plugged (ask me how I know), can you? Same with plugged
statics.

"6PK" > wrote in message
...
On Tuesday, July 30, 2013 12:51:44 AM UTC-7, waremark wrote:
> You guys who find the WP thermal assistant so much better than others -
> are you running them on the same hardware with the same inputs? I hope you
> are not basing any comments on an Oudie using its internal GPS because it
> is known that the info from the internal GPS is not good enough for a
> thermal assistant.

You are absolutely correct. WP Pro is only available and only work with a
compatible flight computer( true airspeed and vario info added I think) and
not with a stand alone gps source.
SYM, XCSoar will offer their version of the thermal assist with a stand
alone gps where they should not; AS IT DOES NOT WORK without a flight
computer!
But to be honest when it comes to their type of thermal assist SYM and
XCSoar don't work very well with a flight computer either.
I'm sure this is all about the algorithms which they won't openly share (as
in guarded secrets).
Like Tim I have used all three (and still have them installed on my
Avier/Vertica2)
None measure up to WPPro when it comes to this feature. Agree; they have a
lot of new and nice features I wish WP would take notes of.
(One would argue; why we need the thermal assits? Answer; why do we need
flight computers, compensated varios, audio varios, or a variometer for that
matter??.)
6PK

Peter Kovari

July 30th 13, 04:34 PM

Sure I can and have many times flying simple club gliders ,it is good exercise.
But this is not the point;
We all invest in better quality equipnent why?;
In order to go farther, higher and faster.
This is just another tool one could adapt or not.
6PK

kirk.stant

July 30th 13, 04:47 PM

On Tuesday, July 30, 2013 7:42:18 AM UTC+2, jfitch wrote:

> Pretty much what he said. I would add that the depiction of all Flarm contacts, with associated information on the Thermal Assistant page is at the very least entertaining and very good for situational awareness.

The trouble with all these graphic displays is that they require a certain amount of time to look at and analyze the data presented prior to using it to center the thermal. We use audio varios to get away from looking at a needle, and now we have pretty pictures!

I use SYM but not the climb page - instead I have a Themi that consistently reminds me to move towards the stronger part of the circle (wind corrected). Usually I've already decided to move my circle when the Themi lights up, but sometimes it does a better job of remembering where the surge is.

SYM has a provision for an aural cue to suggest when to roll out to move the circle, but haven't tried it.

Considering the age of Themi, and the fact that it uses (as far as I know) only GPS to track the thermal, I'm surprised there hasn't been a second generation Themi2 that would use better sensors to map the thermal, but still keep the simple visual cues (LEDs on the glareshield).

Kirk
66

jfitch

July 30th 13, 05:38 PM

On Tuesday, July 30, 2013 12:51:44 AM UTC-7, waremark wrote:
> You guys who find the WP thermal assistant so much better than others - are you running them on the same hardware with the same inputs? I hope you are not basing any comments on an Oudie using its internal GPS because it is known that the info from the internal GPS is not good enough for a thermal assistant.

I have SYM, XCSoar, Winpilot Pro and Adv, LK8000 all loaded on the Avier, all accepting the same input from the Butterfly including GPS and barometric data. I also have Winpilot iOS and iGlide Pro on the iPhone. Very shortly I will have these connected to the Butterfly for GPS and barometric data as well. I have tried them all, often switching between them on the same flight in the same conditions. (I don't need to look out of the cockpit - I have Flarm and an AH :) ). SYM and XCSoar (and its derivatives) have more features than Winpilot - but for the most part I don't find those features particularly useful. The Winpilot Pro thermal assistant simply works better than the others. I would not bother to use the others, frankly. I think the reason thermal assistants have gotten a bad reputation is from those not using the Winpilot version. The others don't appear when you want them, aren't useful once they appear, and don't dismiss themselves in a timely fashion when you are done.

Even Naviter doesn't believe in their version. Directly quoted from the manual: "We will be happy if you continue to enjoy soaring and if you never find the need to use the Thermal Assistant at all :-)". I agree with them, for their version.

The other main difference between Winpilot and the other PDA software is that the Winpilot authors have had some experience in man-machine interaction.. The UI is more concise and considers the cockpit environment.

Now regarding head down time with all this junk in the cockpit. They are distractions, but the extent of the distraction depends to a great extent on the presentation and user interface. The Winpilot thermal assistant requires about a half second glance a couple of times each circle while you are attempting to center. There is no reason to study it. There is no interaction required to call it up or dismiss it. In contrast, try to insert a waypoint in SYM or XCSoar while you are thermaling (or even cruising). Now there is some head down time. The Avier/V2/Oudie do not make this any easier with its poor touchscreen.

The iOS offerings seem to have made a leap in UI. Both Winpilot iOS and iGlide have significantly better user interfaces than any of the PDA offerings.. You can simply do a lot more with a lot less attention. However both products are not really feature complete yet - for example neither has a thermal assistant - but they are getting pretty close.

Peter Kovari

July 30th 13, 08:49 PM

I did not realise that the Butterfly was competible with WinPilot Pro?
One of the short comings of WP is the lack of compability with most newer flight computers.
6PK

jfitch

July 30th 13, 10:59 PM

On Tuesday, July 30, 2013 12:49:06 PM UTC-7, Peter Kovari wrote:
> I did not realise that the Butterfly was competible with WinPilot Pro?
>
> One of the short comings of WP is the lack of compability with most newer flight computers.
>
> 6PK

The Butterfly emulates an LX or CAI302 (for the most part) so Winpilot does work. I would contact Winpilot and ask - he may have a special version that omits the initialization sequences (which the Butterfly ignores and can cause problems with Flarm installed). The regular Avier 12.5 will run if you set the Butterfly to LX output and turn off Flarm sentences.

The just posted Winpilot iOS manual update says it explicitly supports the Butterfly in an upcoming release.

WinPilot

July 30th 13, 11:03 PM

WinPilot PRO for Avier that is now on WinPilot.com is compatible with the Butterfly vario.
To enable Butterfly support, please go into Menu.About.Hardware and enable 'Butterfly Vario'.

Also, we have added support for Butterly vario to our WinPilot for iOS version.

Anybody who has a mini-iPad or iPhone and a Butterly vario with their 'WiFi Dongle' device please contact us for a free version for WinPilot for iOS to test it.

People who have other flight computers can now connect to WinPilot for iOS version 1.63 or newer wirelessly by using this device:
http://www.butterfly-avionics.com/index.php/en/products/connect-ipadiphone

winpilot team

WinPilot

July 30th 13, 11:10 PM

Here is the corrected link for the connection module for WinPilot for iOS:

http://www.butterfly-avionics.com/index.php/en/products/connect-ipadiphone-verbindungsmodul

[email protected]

July 31st 13, 12:43 AM

On Tuesday, July 30, 2013 5:10:03 PM UTC-5, WinPilot wrote:
> Here is the corrected link for the connection module for WinPilot for iOS:
>
>
>
> http://www.butterfly-avionics.com/index.php/en/products/connect-ipadiphone-verbindungsmodul

Team Winpilot,
Since this has become a place to discuss my favorite soaring software, two requests for the Avier/Vertica version: Please make it easier to change the zoom level through gestures or taps and secondly, bring back the 4 "hardware buttons" from the IPAQ that engaged often used functions such as Task Manager, Statistics, Map Display etc. Just use some screen space at the bottom for those buttons.
Thanks,
Herb

Peter Kovari

July 31st 13, 02:06 AM

I ditto that. 6PK

Frank Whiteley

July 31st 13, 10:06 PM

On Monday, July 29, 2013 10:00:11 AM UTC-6, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

Think plumes.
http://www.rcsoaring.com/docs/thermals_2006.pdf

[email protected]

August 1st 13, 08:16 PM

On Monday, July 29, 2013 12:00:11 PM UTC-4, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

Perhaps but since we usually fly in a circle anyways in a thermal, does it matter all that much? I've love to thermal in a trapezoid but I think it would make it really hard for those in the same thermal. :D

Naviter Info

August 1st 13, 11:20 PM

Some really good points here about thermal assistants, thanks.

> Even Naviter doesn't believe in their version

Good point and largely true. For this reason the visual aspects of the Thermal assistant have been completely redesigned for the version which has been released earlier today (SeeYou Mobile 4.50). More about it (and other news) here:
http://www.naviter.com/2013/08/new-versions-and-new-logos/

There's also a discussion on a same/similar topic here:
http://forum.naviter.com/threads/4942-Thermal-Assist-Question-Moves-with-my-Moves

I dare to say that accurate thermal assistants are a myth and that head down time during circling is a waste unless you are consciously learning a particular technique. At the same time - I do keep the "ding ding" thermal assistant active most of the time. Mainly because at times I become useless when I am talking on the radio, looking at my landing options or become plain old tired. That's when the thermal assistant's "ding ding" is usually right and very useful.

Regards,
Andrej Kolar
--
glider pilots use
http://www.Naviter.com

On Tuesday, July 30, 2013 6:38:56 PM UTC+2, jfitch wrote:
> On Tuesday, July 30, 2013 12:51:44 AM UTC-7, waremark wrote:
>
> > You guys who find the WP thermal assistant so much better than others - are you running them on the same hardware with the same inputs? I hope you are not basing any comments on an Oudie using its internal GPS because it is known that the info from the internal GPS is not good enough for a thermal assistant.
>
>
>
> I have SYM, XCSoar, Winpilot Pro and Adv, LK8000 all loaded on the Avier, all accepting the same input from the Butterfly including GPS and barometric data. I also have Winpilot iOS and iGlide Pro on the iPhone. Very shortly I will have these connected to the Butterfly for GPS and barometric data as well. I have tried them all, often switching between them on the same flight in the same conditions. (I don't need to look out of the cockpit - I have Flarm and an AH :) ). SYM and XCSoar (and its derivatives) have more features than Winpilot - but for the most part I don't find those features particularly useful. The Winpilot Pro thermal assistant simply works better than the others. I would not bother to use the others, frankly. I think the reason thermal assistants have gotten a bad reputation is from those not using the Winpilot version. The others don't appear when you want them, aren't useful once they appear, and don't dismiss themselves in a timely fashion when you are done.
>
>
>
> Even Naviter doesn't believe in their version. Directly quoted from the manual: "We will be happy if you continue to enjoy soaring and if you never find the need to use the Thermal Assistant at all :-)". I agree with them, for their version.
>
>
>
> The other main difference between Winpilot and the other PDA software is that the Winpilot authors have had some experience in man-machine interaction. The UI is more concise and considers the cockpit environment.
>
>
>
> Now regarding head down time with all this junk in the cockpit. They are distractions, but the extent of the distraction depends to a great extent on the presentation and user interface. The Winpilot thermal assistant requires about a half second glance a couple of times each circle while you are attempting to center. There is no reason to study it. There is no interaction required to call it up or dismiss it. In contrast, try to insert a waypoint in SYM or XCSoar while you are thermaling (or even cruising). Now there is some head down time. The Avier/V2/Oudie do not make this any easier with its poor touchscreen.
>
>
>
> The iOS offerings seem to have made a leap in UI. Both Winpilot iOS and iGlide have significantly better user interfaces than any of the PDA offerings. You can simply do a lot more with a lot less attention. However both products are not really feature complete yet - for example neither has a thermal assistant - but they are getting pretty close.

jfitch

August 2nd 13, 01:29 AM

On Thursday, August 1, 2013 3:20:49 PM UTC-7, Naviter Info wrote:
> Some really good points here about thermal assistants, thanks.
>
>
>
> > Even Naviter doesn't believe in their version
>
>
>
> Good point and largely true. For this reason the visual aspects of the Thermal assistant have been completely redesigned for the version which has been released earlier today (SeeYou Mobile 4.50). More about it (and other news) here:
>
> http://www.naviter.com/2013/08/new-versions-and-new-logos/
>
>
>
> There's also a discussion on a same/similar topic here:
>
> http://forum.naviter.com/threads/4942-Thermal-Assist-Question-Moves-with-my-Moves
>
>
>
> I dare to say that accurate thermal assistants are a myth and that head down time during circling is a waste unless you are consciously learning a particular technique. At the same time - I do keep the "ding ding" thermal assistant active most of the time. Mainly because at times I become useless when I am talking on the radio, looking at my landing options or become plain old tired. That's when the thermal assistant's "ding ding" is usually right and very useful.
>
>
>
> Regards,
>
> Andrej Kolar
>
> --
>
> glider pilots use
>
> http://www.Naviter.com
>
>
>
> On Tuesday, July 30, 2013 6:38:56 PM UTC+2, jfitch wrote:
>
> > On Tuesday, July 30, 2013 12:51:44 AM UTC-7, waremark wrote:
>
> >
>
> > > You guys who find the WP thermal assistant so much better than others - are you running them on the same hardware with the same inputs? I hope you are not basing any comments on an Oudie using its internal GPS because it is known that the info from the internal GPS is not good enough for a thermal assistant.
>
> >
>
> >
>
> >
>
> > I have SYM, XCSoar, Winpilot Pro and Adv, LK8000 all loaded on the Avier, all accepting the same input from the Butterfly including GPS and barometric data. I also have Winpilot iOS and iGlide Pro on the iPhone. Very shortly I will have these connected to the Butterfly for GPS and barometric data as well. I have tried them all, often switching between them on the same flight in the same conditions. (I don't need to look out of the cockpit - I have Flarm and an AH :) ). SYM and XCSoar (and its derivatives) have more features than Winpilot - but for the most part I don't find those features particularly useful. The Winpilot Pro thermal assistant simply works better than the others. I would not bother to use the others, frankly. I think the reason thermal assistants have gotten a bad reputation is from those not using the Winpilot version. The others don't appear when you want them, aren't useful once they appear, and don't dismiss themselves in a timely fashion when you are done.
>
> >
>
> >
>
> >
>
> > Even Naviter doesn't believe in their version. Directly quoted from the manual: "We will be happy if you continue to enjoy soaring and if you never find the need to use the Thermal Assistant at all :-)". I agree with them, for their version.
>
> >
>
> >
>
> >
>
> > The other main difference between Winpilot and the other PDA software is that the Winpilot authors have had some experience in man-machine interaction. The UI is more concise and considers the cockpit environment.
>
> >
>
> >
>
> >
>
> > Now regarding head down time with all this junk in the cockpit. They are distractions, but the extent of the distraction depends to a great extent on the presentation and user interface. The Winpilot thermal assistant requires about a half second glance a couple of times each circle while you are attempting to center. There is no reason to study it. There is no interaction required to call it up or dismiss it. In contrast, try to insert a waypoint in SYM or XCSoar while you are thermaling (or even cruising). Now there is some head down time. The Avier/V2/Oudie do not make this any easier with its poor touchscreen.
>
> >
>
> >
>
> >
>
> > The iOS offerings seem to have made a leap in UI. Both Winpilot iOS and iGlide have significantly better user interfaces than any of the PDA offerings. You can simply do a lot more with a lot less attention. However both products are not really feature complete yet - for example neither has a thermal assistant - but they are getting pretty close.

"I dare to say that accurate thermal assistants are a myth and that head down time during circling is a waste unless you are consciously learning a particular technique."

All I can say is try the Winpilot Pro version. There is very little head down time (a whole lot less than you spend on Flarm, as a comparison). There are rare instances when I think I can do better than the thermal assistants suggestion, but most of the time not. Of course it will not tell you where under the cloud to look, or that you may be precisely centering a small side tendril and the real core is over on the other side. Finding the lift is art. Centering it is science, and science can be reduced to an algorithm. Computers, correctly programmed, are very good at algorithms - without head down time or otherwise adding to pilot workload.

But I will try the reworked Naviter version!

Dan Marotta

August 2nd 13, 02:55 PM

An algorithm works for a single case and each thermal is different.

"jfitch" > wrote in message
...

<a lot of snipping> Finding the lift is art. Centering it is science, and
science can be reduced to an algorithm. Computers, correctly programmed, are
very good at algorithms - without head down time or otherwise adding to
pilot workload.

But I will try the reworked Naviter version!

Tim Taylor

August 2nd 13, 04:45 PM

>> All I can say is try the Winpilot Pro version. There is very little head down time (a whole lot less than you spend on Flarm, as a comparison). There are rare instances when I think I can do better than the thermal assistants suggestion, but most of the time not. Of course it will not tell you where under the cloud to look, or that you may be precisely centering a small side tendril and the real core is over on the other side. Finding the lift is art. Centering it is science, and science can be reduced to an algorithm. Computers, correctly programmed, are very good at algorithms - without head down time or otherwise adding to pilot workload.
>
>
>
> But I will try the reworked Naviter version!

Andrej, Thank you for working on the Thermal Assistant. I updated my Oudie yesterday and look forward to flying with it in a few days.

I encourage you to look at adding a thermal strength graph as well for the display. I concur with Jon that the WinPilot interface took almost no heads down time and as with SYM the beep was enough to adjust most of the time.

One comment on the difference in perceived benefit for a TA with any software. There may be a geographical bias for the preference for them. In the western US and I would guess similar location like Australia and South Africa we deal with very different thermals from the Eastern US and most of Central Europe. The thermals range from very small cores with 10 to 12 knot centers (5 to 6 m/s) to very large with two to three cores with a total range of 12 or more knots in lift and sink. It is literally like riding a bucking bronco. In addition there are often windy blue days where finding a small core off tow the direction of a TA is helpful. Most of us have found that we gain a slight advantage with a good Thermal Assistant like the one WinPilot implemented many years ago.

jfitch

August 2nd 13, 06:11 PM

On Friday, August 2, 2013 8:45:34 AM UTC-7, Tim Taylor wrote:
> >> All I can say is try the Winpilot Pro version. There is very little head down time (a whole lot less than you spend on Flarm, as a comparison). There are rare instances when I think I can do better than the thermal assistants suggestion, but most of the time not. Of course it will not tell you where under the cloud to look, or that you may be precisely centering a small side tendril and the real core is over on the other side. Finding the lift is art. Centering it is science, and science can be reduced to an algorithm. Computers, correctly programmed, are very good at algorithms - without head down time or otherwise adding to pilot workload.
>
> >
>
> >
>
> >
>
> > But I will try the reworked Naviter version!
>
>
>
> Andrej, Thank you for working on the Thermal Assistant. I updated my Oudie yesterday and look forward to flying with it in a few days.
>
>
>
> I encourage you to look at adding a thermal strength graph as well for the display. I concur with Jon that the WinPilot interface took almost no heads down time and as with SYM the beep was enough to adjust most of the time.
>
>
>
> One comment on the difference in perceived benefit for a TA with any software. There may be a geographical bias for the preference for them. In the western US and I would guess similar location like Australia and South Africa we deal with very different thermals from the Eastern US and most of Central Europe. The thermals range from very small cores with 10 to 12 knot centers (5 to 6 m/s) to very large with two to three cores with a total range of 12 or more knots in lift and sink. It is literally like riding a bucking bronco. In addition there are often windy blue days where finding a small core off tow the direction of a TA is helpful. Most of us have found that we gain a slight advantage with a good Thermal Assistant like the one WinPilot implemented many years ago.

Good point about the difference in thermals.

As a data point, I fly an ASH26E. After launch and climb, the engine is shut down and folded back, but left a bit out with the engine bay doors open for a cooling period of several minutes. During that period the tail pneumatics are subject to turbulance from the prop and doors that results in rapid random +/- 3 or 4 m/s swings in the variometer. Only with extreme attention can you find your way towards the core in these circumstances, and then only if it is a fairly uniform core. Or you can simply do what the Winpilot thermal assistant tells you based on the same information. It is able to make at least as much sense of the trash as I can, and requires no attention at all. .

bill palmer

August 2nd 13, 08:49 PM

On Monday, July 29, 2013 4:45:35 PM UTC-7, Dan Marotta wrote:
....
>
> I learned a long time ago to tighten up when lift falls off and ease up a
>
> bit on the bank when the lift goes up. With practice, you'll get it and
>
> won't need a graphical depiction of a thermal.

Isn't it the other way around? (fly tight circles when the lift is good, widen out when not (so you can run into it again?)

Peter Kovari

August 2nd 13, 09:45 PM

No. You got that backwards....

Dan Marotta

August 3rd 13, 05:11 PM

No, as the lift peters out, you want to move away from that area. You do
that by tightening your turn. When I feel a spike in the lift, I let up for
a couple of seconds to drift into the area of strong lift and then tighten
up to try to stay there. More often, as stated elsewhere, the thermal is
not circular and you have to do what you have to do. A depiction of the
areas of stronger and weaker lift can be helpful on weaker days, but we
don't have too many of those here.

Maybe I didn't describe it correctly.

"Bill Palmer" > wrote in message
...
> On Monday, July 29, 2013 4:45:35 PM UTC-7, Dan Marotta wrote:
> ...
>>
>> I learned a long time ago to tighten up when lift falls off and ease up a
>>
>> bit on the bank when the lift goes up. With practice, you'll get it and
>>
>> won't need a graphical depiction of a thermal.
>
> Isn't it the other way around? (fly tight circles when the lift is good,
> widen out when not (so you can run into it again?)

Mike I Green

August 3rd 13, 06:14 PM

When to tighten is very dependent on the tome constant of your variometer.

MG

On 8/3/2013 9:11 AM, Dan Marotta wrote:
> No, as the lift peters out, you want to move away from that area. You
> do that by tightening your turn. When I feel a spike in the lift, I let
> up for a couple of seconds to drift into the area of strong lift and
> then tighten up to try to stay there. More often, as stated elsewhere,
> the thermal is not circular and you have to do what you have to do. A
> depiction of the areas of stronger and weaker lift can be helpful on
> weaker days, but we don't have too many of those here.
>
> Maybe I didn't describe it correctly.
>
>
> "Bill Palmer" > wrote in message
> ...
>> On Monday, July 29, 2013 4:45:35 PM UTC-7, Dan Marotta wrote:
>> ...
>>>
>>> I learned a long time ago to tighten up when lift falls off and ease
>>> up a
>>>
>>> bit on the bank when the lift goes up. With practice, you'll get it and
>>>
>>> won't need a graphical depiction of a thermal.
>>
>> Isn't it the other way around? (fly tight circles when the lift is
>> good, widen out when not (so you can run into it again?)
>

--
Mike I Green

Eric Greenwell[_4_]

August 3rd 13, 07:48 PM

Dan Marotta wrote, On 8/2/2013 6:55 AM:
> An algorithm works for a single case and each thermal is different.

You aren't a programmer, are you? :^)

>
> "jfitch" > wrote in message
> ...
>
> <a lot of snipping> Finding the lift is art. Centering it is science,
> and science can be reduced to an algorithm. Computers, correctly
> programmed, are very good at algorithms - without head down time or
> otherwise adding to pilot workload.
>
> But I will try the reworked Naviter version!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

jfitch

August 3rd 13, 07:50 PM

On Friday, August 2, 2013 6:55:31 AM UTC-7, Dan Marotta wrote:
> An algorithm works for a single case and each thermal is different.
>
>
>
> "jfitch" wrote in message
>
>
>
>
>
> <a lot of snipping> Finding the lift is art. Centering it is science, and
>
> science can be reduced to an algorithm. Computers, correctly programmed, are
>
> very good at algorithms - without head down time or otherwise adding to
>
> pilot workload.
>
>
>
> But I will try the reworked Naviter version!

I disagree - using only the information from your variometer, the algorithm is pretty consistent or almost any thermal you will encounter.

The explanations here seem incomplete. You should tighten or loosen your turn (angle of bank) based on the *rate of change of lift*, not the strength. If you loosen your turn at the peak of lift, you will be 90 degrees out of phase and will not center quickly, if at all. What you want to do is loosen your turn at the peak rate of increase of lift. Alternatively, loosen your turn at 90 degrees prior to the peak lift. When you experience peak lift, you are already at 90 degrees to the desired correction direction (mod vario lag). Human perception is not all that great and estimating rate of change, and recording that rate of change around a complete circle, and relating that to your angular position in that circle accurately, all advanced by the time constant (lag) of the variometer. This is however very easy for the computer.

[email protected]

August 3rd 13, 11:50 PM

Andrej, Tim Taylor accurately describes the conditions we have in the Western United States and why a good thermal assistant is an asset. I still soldier on with WinPilot because it's TA is simply the best. I have a copy of SYM but choose not to fly with it. I would dearly like to dump my PDA and fly with a more modern and supported system.

waremark

August 3rd 13, 11:52 PM

On Monday, 29 July 2013 17:00:11 UTC+1, son_of_flubber wrote:
> I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.

The thread title asks whether thermal assistants assume thermals are round. I would like to know whether thermal assistants assume you are flying a round circle - specifically, when I have made an adjustment to my circle, does the thermal assistant realise I have done so, or does making an adjustment completely invalidate the advice of the thermal assistant until I have completed the next round circle? Does anyone know?

Is there anyone who can give a specific explanation of what each thermal assistant does?

Currently, I am using an LX9000. I like that I get the benefit of a visual thermal assistant without losing the display of any other info, and I think the visual assistant does a good job - I generally find the best and worst lift just where the assistant shows them. I often also zoom the map right in to see my track line with lift colours. I cannot make sense of the audible bleeps. With the Winpilot assistant which I use in another glider, I do not like losing all other info while the assistant is active - whereas with SeeYou Mobile (not talking about the brand new version which obviously I have not yet seen in action) I like being able to retain my navboxes as well as the assistant. I find the Winpilot trend graph pretty but not useful - I decide when to leave a thermal based on the digital averager (and the picture ahead!).

Dan Marotta

August 4th 13, 03:50 PM

Not since they came up with that new-fangled structured FORTRAN. Give me
spaghetti code any day!

But I *am* (was, since I'm retired) a Systems Engineer and I know how to
turn user requirements into a specification that the software engineers can
screw up. Herding cats is a full-time job.

You know, of course, that when the brakes on your car fail, you software
engineers will push the car back up the hill and try again to see if they
still fail. ;-P

"Eric Greenwell" > wrote in message
...
> Dan Marotta wrote, On 8/2/2013 6:55 AM:
>> An algorithm works for a single case and each thermal is different.
>
> You aren't a programmer, are you? :^)
>
>>
>> "jfitch" > wrote in message
>> ...
>>
>> <a lot of snipping> Finding the lift is art. Centering it is science,
>> and science can be reduced to an algorithm. Computers, correctly
>> programmed, are very good at algorithms - without head down time or
>> otherwise adding to pilot workload.
>>
>> But I will try the reworked Naviter version!
>
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email
> me)
> - "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
> http://tinyurl.com/yb3xywl

Dan Marotta

August 4th 13, 04:00 PM

I agree with you on the rate of change aspect and, in that sense, I can see
where you could develop an algorithm that would command changes of turn
radius to maximize time in the strongest lift.

But I fly purely for fun, these days, except for when I'm towing, and I'd
happily wager a beer (or two!) with you that I can out climb you with
variometers and computers powered off. Heck, I'll even cover up the
mechanical vario. No fancy seals required as proof of compliance and I
don't even care if I lose the bet - I'll still get a beer!

"jfitch" > wrote in message
...
On Friday, August 2, 2013 6:55:31 AM UTC-7, Dan Marotta wrote:
> An algorithm works for a single case and each thermal is different.
>
>
>
> "jfitch" wrote in message
>
>
>
>
>
> <a lot of snipping> Finding the lift is art. Centering it is science, and
>
> science can be reduced to an algorithm. Computers, correctly programmed,
> are
>
> very good at algorithms - without head down time or otherwise adding to
>
> pilot workload.
>
>
>
> But I will try the reworked Naviter version!

I disagree - using only the information from your variometer, the algorithm
is pretty consistent or almost any thermal you will encounter.

The explanations here seem incomplete. You should tighten or loosen your
turn (angle of bank) based on the *rate of change of lift*, not the
strength. If you loosen your turn at the peak of lift, you will be 90
degrees out of phase and will not center quickly, if at all. What you want
to do is loosen your turn at the peak rate of increase of lift.
Alternatively, loosen your turn at 90 degrees prior to the peak lift. When
you experience peak lift, you are already at 90 degrees to the desired
correction direction (mod vario lag). Human perception is not all that great
and estimating rate of change, and recording that rate of change around a
complete circle, and relating that to your angular position in that circle
accurately, all advanced by the time constant (lag) of the variometer. This
is however very easy for the computer.

jfitch

August 4th 13, 05:34 PM

On Sunday, August 4, 2013 8:00:28 AM UTC-7, Dan Marotta wrote:
> I agree with you on the rate of change aspect and, in that sense, I can see
>
> where you could develop an algorithm that would command changes of turn
>
> radius to maximize time in the strongest lift.
>
>
>
> But I fly purely for fun, these days, except for when I'm towing, and I'd
>
> happily wager a beer (or two!) with you that I can out climb you with
>
> variometers and computers powered off. Heck, I'll even cover up the
>
> mechanical vario. No fancy seals required as proof of compliance and I
>
> don't even care if I lose the bet - I'll still get a beer!
>
>
>
> "jfitch" wrote in message
>
>
>
> On Friday, August 2, 2013 6:55:31 AM UTC-7, Dan Marotta wrote:
>
> > An algorithm works for a single case and each thermal is different.
>
> >
>
> >
>
> >
>
> > "jfitch" wrote in message
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > <a lot of snipping> Finding the lift is art. Centering it is science, and
>
> >
>
> > science can be reduced to an algorithm. Computers, correctly programmed,
>
> > are
>
> >
>
> > very good at algorithms - without head down time or otherwise adding to
>
> >
>
> > pilot workload.
>
> >
>
> >
>
> >
>
> > But I will try the reworked Naviter version!
>
>
>
> I disagree - using only the information from your variometer, the algorithm
>
> is pretty consistent or almost any thermal you will encounter.
>
>
>
> The explanations here seem incomplete. You should tighten or loosen your
>
> turn (angle of bank) based on the *rate of change of lift*, not the
>
> strength. If you loosen your turn at the peak of lift, you will be 90
>
> degrees out of phase and will not center quickly, if at all. What you want
>
> to do is loosen your turn at the peak rate of increase of lift.
>
> Alternatively, loosen your turn at 90 degrees prior to the peak lift. When
>
> you experience peak lift, you are already at 90 degrees to the desired
>
> correction direction (mod vario lag). Human perception is not all that great
>
> and estimating rate of change, and recording that rate of change around a
>
> complete circle, and relating that to your angular position in that circle
>
> accurately, all advanced by the time constant (lag) of the variometer. This
>
> is however very easy for the computer.

Dan, you're on! Bring your glider out west (and bring lots of beer - you are going to need it).

Waremark,
From observation I believe all thermal assistants do the same thing: identify circling by rate of heading change, record variometer readings around the circle, integrate the readings over angular displacement to calculate a correction vector. There is no need to account for non-round circles or correction movements (other than to the extent that it affects angular displacement), as this information does not affect what you should do.

After all, this is exactly that a good pilot does. If you are high in a blue thermal that is all you can do: your only input is rate of climb and its derivatives. You integrate lift as a function of angular displacement, and reposition the circle the direction of the resultant vector. The computer simply does it in fine grained detail, without fatigue or distraction, and without the perception errors to which human senses are so susceptible. This is particularly true in rough/uneven/strong thermals. A pilot must determine and remember, "was that huge hole I just went through exactly equaled by the huge bump I just got? where they 80 or 110 degrees apart? how does that change the correction vector exactly?" Most humans aren't very good at this, and it requires a substantial amount of attention unless the thermals are well behaved. The less well behaved the thermal, the worse are your perception errors and the more the thermal assistant helps.

What separates the good, bad, and ugly thermal assistants is not the mechanics of recording vario readings or math to calculate the vector, all very straightforward I think. The devil is in the details:

-What algorithm is used to call up and dismiss the thermal assistant? Is it there when you want it and gone when you don't, without having to access menus and poke buttons?

-Is the data presented in a way that can be interpreted at a glance, and is associated data also available (such as average rate of climb, climb in thermal, better/worse than McReady expectation, better/worse than days average)?

-Is non associated but nevertheless important data also available (such as nearby Flarm targets) and easily interpreted with minimum attention?

-Does the algorithm account for data latency (such as varo lag) and reaction time in a useful way?

In my opinion Winpilot is better in each of the details than the others even in its earliest instance (but I haven't tried the latest SYM offering).

Naviter Info

August 4th 13, 10:28 PM

All good points and certainly something we can consider and most importantly - test. Thanks.

Andrej Kolar
--
glider pilots use
http://www.Naviter.com

On Sunday, August 4, 2013 12:50:57 AM UTC+2, wrote:
> Andrej, Tim Taylor accurately describes the conditions we have in the Western United States and why a good thermal assistant is an asset. I still soldier on with WinPilot because it's TA is simply the best. I have a copy of SYM but choose not to fly with it. I would dearly like to dump my PDA and fly with a more modern and supported system.

Naviter Info

August 4th 13, 10:38 PM

> I would like to know whether thermal assistants assume you are flying a round circle

I can obviously only speak for Naviter/SeeYou Mobile/Oudie. We do not assume that you are flying round circles. We remember the direction in which the thermal was strongest in your last turn and base our predictions on that.

> I often also zoom the map right in to see my track line with lift colours..

The new Thermal Assistant in SeeYou Mobile will zoom in automatically, display the track of the last thermal with a thicker line and color-code it according to thermal strength. Even if you come to an area where you have circled before it will be very clear which is your last thermal's track.

> I cannot make sense of the audible bleeps.

We also calculate your rate of turn. And we remember the direction in which the climb was strongest in your previous circle. 4 seconds before you will reach the direction of the peak of the previous circle (by default) we will give you a sound warning if the thresholds of how uneven the thermal may be are exceeded. If you are circling in a nicely centered thermal where the needle doesn't move much we will not bother to disturb you with the thermal assistant beeps.

All of the above only works well if you have at least pressure altitude input (vario input is even better).

Hope this explains how the TA works in SeeYou Mobile,
Andrej Kolar
--
glider pilots use
http://www.Naviter.com

On Sunday, August 4, 2013 12:52:26 AM UTC+2, waremark wrote:
> On Monday, 29 July 2013 17:00:11 UTC+1, son_of_flubber wrote:
>
> > I'm starting to think that the textbook circular thermal is primarily a flatland phenomena.
>
>
>
> The thread title asks whether thermal assistants assume thermals are round. I would like to know whether thermal assistants assume you are flying a round circle - specifically, when I have made an adjustment to my circle, does the thermal assistant realise I have done so, or does making an adjustment completely invalidate the advice of the thermal assistant until I have completed the next round circle? Does anyone know?
>
>
>
> Is there anyone who can give a specific explanation of what each thermal assistant does?
>
>
>
> Currently, I am using an LX9000. I like that I get the benefit of a visual thermal assistant without losing the display of any other info, and I think the visual assistant does a good job - I generally find the best and worst lift just where the assistant shows them. I often also zoom the map right in to see my track line with lift colours. I cannot make sense of the audible bleeps. With the Winpilot assistant which I use in another glider, I do not like losing all other info while the assistant is active - whereas with SeeYou Mobile (not talking about the brand new version which obviously I have not yet seen in action) I like being able to retain my navboxes as well as the assistant. I find the Winpilot trend graph pretty but not useful - I decide when to leave a thermal based on the digital averager (and the picture ahead!).

Dan Marotta

August 5th 13, 12:37 AM

Gee, whiz, while that was a terrific explanation of a thermal assistant, for
me, at least, it removes all vestiges of fun from thermalling. Clearly
you're still employed as an engineer and enjoy your work, but I'm retired
and enjoy the freedom of plodding along without needing doodads to get that
last increment of performance.

I issued my beer challenge as a way of having a good time and demonstrating
that all those aids aren't necessary for a good time. I've no doubt that
given two equally talented pilots in identical ships, then the one with the
better instruments will probably do better. Does that mean he'll get all
the chicks, money, and endorsements?

BTW, I *am* out west - Moriarty. Where are you?

"jfitch" > wrote in message
...
On Sunday, August 4, 2013 8:00:28 AM UTC-7, Dan Marotta wrote:
> I agree with you on the rate of change aspect and, in that sense, I can
> see
>
> where you could develop an algorithm that would command changes of turn
>
> radius to maximize time in the strongest lift.
>
>
>
> But I fly purely for fun, these days, except for when I'm towing, and I'd
>
> happily wager a beer (or two!) with you that I can out climb you with
>
> variometers and computers powered off. Heck, I'll even cover up the
>
> mechanical vario. No fancy seals required as proof of compliance and I
>
> don't even care if I lose the bet - I'll still get a beer!
>
>
>
> "jfitch" wrote in message
>
>
>
> On Friday, August 2, 2013 6:55:31 AM UTC-7, Dan Marotta wrote:
>
> > An algorithm works for a single case and each thermal is different.
>
> >
>
> >
>
> >
>
> > "jfitch" wrote in message
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > <a lot of snipping> Finding the lift is art. Centering it is science,
> > and
>
> >
>
> > science can be reduced to an algorithm. Computers, correctly programmed,
>
> > are
>
> >
>
> > very good at algorithms - without head down time or otherwise adding to
>
> >
>
> > pilot workload.
>
> >
>
> >
>
> >
>
> > But I will try the reworked Naviter version!
>
>
>
> I disagree - using only the information from your variometer, the
> algorithm
>
> is pretty consistent or almost any thermal you will encounter.
>
>
>
> The explanations here seem incomplete. You should tighten or loosen your
>
> turn (angle of bank) based on the *rate of change of lift*, not the
>
> strength. If you loosen your turn at the peak of lift, you will be 90
>
> degrees out of phase and will not center quickly, if at all. What you want
>
> to do is loosen your turn at the peak rate of increase of lift.
>
> Alternatively, loosen your turn at 90 degrees prior to the peak lift. When
>
> you experience peak lift, you are already at 90 degrees to the desired
>
> correction direction (mod vario lag). Human perception is not all that
> great
>
> and estimating rate of change, and recording that rate of change around a
>
> complete circle, and relating that to your angular position in that circle
>
> accurately, all advanced by the time constant (lag) of the variometer.
> This
>
> is however very easy for the computer.

Dan, you're on! Bring your glider out west (and bring lots of beer - you are
going to need it).

Waremark,
From observation I believe all thermal assistants do the same thing:
identify circling by rate of heading change, record variometer readings
around the circle, integrate the readings over angular displacement to
calculate a correction vector. There is no need to account for non-round
circles or correction movements (other than to the extent that it affects
angular displacement), as this information does not affect what you should
do.

After all, this is exactly that a good pilot does. If you are high in a blue
thermal that is all you can do: your only input is rate of climb and its
derivatives. You integrate lift as a function of angular displacement, and
reposition the circle the direction of the resultant vector. The computer
simply does it in fine grained detail, without fatigue or distraction, and
without the perception errors to which human senses are so susceptible.
This is particularly true in rough/uneven/strong thermals. A pilot must
determine and remember, "was that huge hole I just went through exactly
equaled by the huge bump I just got? where they 80 or 110 degrees apart? how
does that change the correction vector exactly?" Most humans aren't very
good at this, and it requires a substantial amount of attention unless the
thermals are well behaved. The less well behaved the thermal, the worse are
your perception errors and the more the thermal assistant helps.

What separates the good, bad, and ugly thermal assistants is not the
mechanics of recording vario readings or math to calculate the vector, all
very straightforward I think. The devil is in the details:

-What algorithm is used to call up and dismiss the thermal assistant? Is it
there when you want it and gone when you don't, without having to access
menus and poke buttons?

-Is the data presented in a way that can be interpreted at a glance, and is
associated data also available (such as average rate of climb, climb in
thermal, better/worse than McReady expectation, better/worse than days
average)?

-Is non associated but nevertheless important data also available (such as
nearby Flarm targets) and easily interpreted with minimum attention?

-Does the algorithm account for data latency (such as varo lag) and reaction
time in a useful way?

In my opinion Winpilot is better in each of the details than the others even
in its earliest instance (but I haven't tried the latest SYM offering).

son_of_flubber

August 5th 13, 03:25 AM

On Sunday, August 4, 2013 7:37:20 PM UTC-4, Dan Marotta wrote:
> Gee, whiz, while that was a terrific explanation of a thermal assistant, for
> me, at least, it removes all vestiges of fun from thermalling.

Most of us got your point the third or fourth time that you made it in this thread about how thermals and thermal assistants work.

jfitch

August 5th 13, 06:16 AM

On Sunday, August 4, 2013 4:37:20 PM UTC-7, Dan Marotta wrote:

>
> BTW, I *am* out west - Moriarty. Where are you?
>
>

There is still about 1/3 of the continent to the left of Moriarty.....

Mike the Strike

August 10th 13, 05:44 AM

Flew with updated SeeYou Mobile Thermal Assistant today - definitely better than the old one - reserving judgement on usefulness!

Mike

[email protected]

August 10th 13, 02:57 PM

On Tuesday, July 30, 2013 1:54:13 AM UTC+1, jfitch wrote:
> Thermals may not be circular, but your glider flies in a pretty good approximation of a circle. So the cylindrical graph depicted in Winpilot is all the information you can really use. XCSoar's polar graph might fool you into thinking that is the shape of the lift - but it is a polar graph of strength around a fixed radius circle, not a map of the thermal. Oh yeah they are different!

'fixed radius circle' implies to me that XCSoar's assistant is trying to estimate the lift over a fixed area - eg a 250m wide circle. Just to clarify: XCSoar's thermal assistant is simply a 36-point plot of the lift recorded vs heading over the last turn. While your heading lies within a single 10 degree block, one of these points is continuously updated with your instantaneous vario value. When your heading crosses into the next 10 degree block, the next point is updated, and so on.

In practical terms this means that any sections where you hold a constant heading are ignored on the plot. As an extreme example, imagine you're flying a racetrack pattern between two cores. You've turned the first 180 degrees in the first core and have just completed the remaining 180 degrees in the second core. The top half of the thermal assistant would show the lift encountered during your 180-degree turn in the first core, and the bottom half would show the result of your 180-degree turn in the second core. Any lift or sink you encountered on the straight leg between the first and second cores would not be represented on the plot.

The line in the middle of the plot just points to the centre of the polygon..

jfitch

August 10th 13, 04:02 PM

On Saturday, August 10, 2013 6:57:04 AM UTC-7, wrote:
> On Tuesday, July 30, 2013 1:54:13 AM UTC+1, jfitch wrote:
>
> > Thermals may not be circular, but your glider flies in a pretty good approximation of a circle. So the cylindrical graph depicted in Winpilot is all the information you can really use. XCSoar's polar graph might fool you into thinking that is the shape of the lift - but it is a polar graph of strength around a fixed radius circle, not a map of the thermal. Oh yeah they are different!
>
>
>
> 'fixed radius circle' implies to me that XCSoar's assistant is trying to estimate the lift over a fixed area - eg a 250m wide circle. Just to clarify: XCSoar's thermal assistant is simply a 36-point plot of the lift recorded vs heading over the last turn. While your heading lies within a single 10 degree block, one of these points is continuously updated with your instantaneous vario value. When your heading crosses into the next 10 degree block, the next point is updated, and so on.
>
>
>
> In practical terms this means that any sections where you hold a constant heading are ignored on the plot. As an extreme example, imagine you're flying a racetrack pattern between two cores. You've turned the first 180 degrees in the first core and have just completed the remaining 180 degrees in the second core. The top half of the thermal assistant would show the lift encountered during your 180-degree turn in the first core, and the bottom half would show the result of your 180-degree turn in the second core. Any lift or sink you encountered on the straight leg between the first and second cores would not be represented on the plot.
>
>
>
> The line in the middle of the plot just points to the centre of the polygon.

Thanks for clarifying my explanation, that is precisely how I thought it (and Winpilot) works. A graph of lift as a function of angular (heading) displacement.

I do not understand the value of plotting lift strength vs. geographical position as is done by some programs. In the thermals I fly, the thermal is at least drifting with the local wind, and often not in an orderly way. The last circle's track has little predictive value for the next (they may be displaced by half a diameter or more) unless the last circle's track is drifted with the predicted wind - and that is not reliable near a rough western thermal. This does have some value in ridge or wave flying, but not in thermals.

Dan Marotta

August 10th 13, 04:43 PM

Your glider is drifting with the wind, too...

"jfitch" > wrote in message
...
On Saturday, August 10, 2013 6:57:04 AM UTC-7, wrote:
> On Tuesday, July 30, 2013 1:54:13 AM UTC+1, jfitch wrote:
>
> > Thermals may not be circular, but your glider flies in a pretty good
> > approximation of a circle. So the cylindrical graph depicted in Winpilot
> > is all the information you can really use. XCSoar's polar graph might
> > fool you into thinking that is the shape of the lift - but it is a polar
> > graph of strength around a fixed radius circle, not a map of the
> > thermal. Oh yeah they are different!
>
>
>
> 'fixed radius circle' implies to me that XCSoar's assistant is trying to
> estimate the lift over a fixed area - eg a 250m wide circle. Just to
> clarify: XCSoar's thermal assistant is simply a 36-point plot of the lift
> recorded vs heading over the last turn. While your heading lies within a
> single 10 degree block, one of these points is continuously updated with
> your instantaneous vario value. When your heading crosses into the next 10
> degree block, the next point is updated, and so on.
>
>
>
> In practical terms this means that any sections where you hold a constant
> heading are ignored on the plot. As an extreme example, imagine you're
> flying a racetrack pattern between two cores. You've turned the first 180
> degrees in the first core and have just completed the remaining 180
> degrees in the second core. The top half of the thermal assistant would
> show the lift encountered during your 180-degree turn in the first core,
> and the bottom half would show the result of your 180-degree turn in the
> second core. Any lift or sink you encountered on the straight leg between
> the first and second cores would not be represented on the plot.
>
>
>
> The line in the middle of the plot just points to the centre of the
> polygon.

Thanks for clarifying my explanation, that is precisely how I thought it
(and Winpilot) works. A graph of lift as a function of angular (heading)
displacement.

I do not understand the value of plotting lift strength vs. geographical
position as is done by some programs. In the thermals I fly, the thermal is
at least drifting with the local wind, and often not in an orderly way. The
last circle's track has little predictive value for the next (they may be
displaced by half a diameter or more) unless the last circle's track is
drifted with the predicted wind - and that is not reliable near a rough
western thermal. This does have some value in ridge or wave flying, but not
in thermals.

Kimmo Hytoenen

August 10th 13, 10:37 PM

I have been using XCSoar thermalling assistant in 8 club gliders.
As pointed out earlier, it works better when connected with a
variometer. But it gives you some idea what is happening even
with GPS only. My experience is, that the most important thing
is to adjust timing of you corrections for each glider. It's easier
now, when we have 3 or our gliders with same variometer/flarm
systems.

I was flying few days ago using the latest XCSoar test version.
There was an interesting new feature - while circling, it is
drawing an arc in front of the glider, predicting where your
current bank and speed will bring you. It worked surprisingly well
when I was using it on backseat of our Janus, with LG phone and
without flight computer connection. The glider track was set to
color the lifting areas yellowish, sinks blue(s), and I was using
this new graphic tool to aim my course to the area of strongest
lift.

I also had the thermal assistant as an infobox, as well as the
thermal gain graph.

Since these systems tell you what has happened past 30 secs
and where, they might give you some information you can use to
make your corrections. Or to leave the thermal. Nothing more.

XCSoar seems to have a feature that calculates the central
point of the lift, but I have not found that useful. Maybe I have
not got the right idea off how to utilize it.

At 13:57 10 August 2013, wrote:
>On Tuesday, July 30, 2013 1:54:13 AM UTC+1, jfitch wrote:
>> Thermals may not be circular, but your glider flies in a pretty
good
>appr=
>oximation of a circle. So the cylindrical graph depicted in
Winpilot is
>all=
> the information you can really use. XCSoar's polar graph might
fool you
>in=
>to thinking that is the shape of the lift - but it is a polar graph
of
>stre=
>ngth around a fixed radius circle, not a map of the thermal. Oh
yeah they
>a=
>re different!
>
>'fixed radius circle' implies to me that XCSoar's assistant is
trying to
>es=
>timate the lift over a fixed area - eg a 250m wide circle. Just to
>clarify:=
> XCSoar's thermal assistant is simply a 36-point plot of the lift
recorded
>=
>vs heading over the last turn. While your heading lies within a
single 10
>d=
>egree block, one of these points is continuously updated with
your
>instanta=
>neous vario value. When your heading crosses into the next 10
degree
>block,=
> the next point is updated, and so on.
>
>In practical terms this means that any sections where you hold
a constant
>h=
>eading are ignored on the plot. As an extreme example, imagine
you're
>flyin=
>g a racetrack pattern between two cores. You've turned the
first 180
>degree=
>s in the first core and have just completed the remaining 180
degrees in
>th=
>e second core. The top half of the thermal assistant would
show the lift
>en=
>countered during your 180-degree turn in the first core, and
the bottom
>hal=
>f would show the result of your 180-degree turn in the second
core. Any
>lif=
>t or sink you encountered on the straight leg between the first
and second
>=
>cores would not be represented on the plot.
>
>The line in the middle of the plot just points to the centre of
the
>polygon=
>..
>

Kimmo Hytoenen

August 10th 13, 10:37 PM

jfitch

August 11th 13, 05:29 AM

On Saturday, August 10, 2013 8:43:05 AM UTC-7, Dan Marotta wrote:
> Your glider is drifting with the wind, too...
>
>

Unfortunately, the earth, and the GPS system that tracks with it, is not.....

Dan Marotta

August 11th 13, 06:19 PM

What are you trying to say. Seems to me that the airmass is carrying the
thermal along and the glider with it. With that premise, circling in calm
air or in a wind makes no difference. I've thermalled straight up and with
a 20+ kt drift down wind. I never had to hold heading into a wind to
maintain center in a thermal.

Or do I misunderstand what you're saying? If that's the case, please
elaborate.

"jfitch" > wrote in message
...
> On Saturday, August 10, 2013 8:43:05 AM UTC-7, Dan Marotta wrote:
>> Your glider is drifting with the wind, too...
>>
>>
>
>
> Unfortunately, the earth, and the GPS system that tracks with it, is
> not.....

son_of_flubber

August 12th 13, 01:03 AM

On Sunday, August 11, 2013 1:19:40 PM UTC-4, Dan Marotta wrote:
>I never had to hold heading into a wind to
> maintain center in a thermal.

Does it work like this east of Ohio?

jfitch

August 12th 13, 05:59 AM

On Sunday, August 11, 2013 10:19:40 AM UTC-7, Dan Marotta wrote:
> What are you trying to say. Seems to me that the airmass is carrying the
>
> thermal along and the glider with it. With that premise, circling in calm
>
> air or in a wind makes no difference. I've thermalled straight up and with
>
> a 20+ kt drift down wind. I never had to hold heading into a wind to
>
> maintain center in a thermal.
>
>
>
> Or do I misunderstand what you're saying? If that's the case, please
>
> elaborate.
>
>
>
>
>
>
>
> ...
>
> > On Saturday, August 10, 2013 8:43:05 AM UTC-7, Dan Marotta wrote:
>
> >> Your glider is drifting with the wind, too...
>
> >>
>
> >>
>
> >
>
> >
>
> > Unfortunately, the earth, and the GPS system that tracks with it, is
>
> > not.....

It makes a difference if you are trying to relate your thermaling track to a track projected to the ground. Some thermal assistants (like SYM) draw a track on the ground color coded by climb rate. If you are drifting with the wind, this track quickly drifts upwind relative to you and the airmass (which are drifting downwind). Therefore the next time around your circle, the track will not have much relevance. The only thing that matters (as you have said) is the glider relative to the airmass, which the GPS cannot accurately track and plot. That relationship has to be inertially derived, or simple inferred to be static. The GPS plot is relative to the earth, which can be thought of as moving underneath you at the speed of the wind. Such a plot is of little value when thermaling though they can be useful for ridge and wave, which are effectively anchored to the earth.

There have been some attempts to guess the drift of the thermal from an assumed or calculated wind speed, but most thermals where I fly are not so well behaved.

Dan Marotta

August 12th 13, 04:49 PM

Thanks - now I see what you mean. My confusion was because XCSoar does a
pretty good job of predicting the wind drift (due to getting good
information from my CAI302) and so the flight track (rather than ground
track) is displayed while circling. This makes it pretty easy to get back
to the lift if, due to inattention or poor decisions, you get out of it.

Slightly off topic, but IIRC I can set up the software so that it accounts
for wind drift while circling and not in straight flight. I say this
because I use the track to stay in the best lift while wave flying.

"jfitch" > wrote in message
...
On Sunday, August 11, 2013 10:19:40 AM UTC-7, Dan Marotta wrote:
> What are you trying to say. Seems to me that the airmass is carrying the
>
> thermal along and the glider with it. With that premise, circling in calm
>
> air or in a wind makes no difference. I've thermalled straight up and
> with
>
> a 20+ kt drift down wind. I never had to hold heading into a wind to
>
> maintain center in a thermal.
>
>
>
> Or do I misunderstand what you're saying? If that's the case, please
>
> elaborate.
>
>
>
>
>
>
>
> ...
>
> > On Saturday, August 10, 2013 8:43:05 AM UTC-7, Dan Marotta wrote:
>
> >> Your glider is drifting with the wind, too...
>
> >>
>
> >>
>
> >
>
> >
>
> > Unfortunately, the earth, and the GPS system that tracks with it, is
>
> > not.....

It makes a difference if you are trying to relate your thermaling track to a
track projected to the ground. Some thermal assistants (like SYM) draw a
track on the ground color coded by climb rate. If you are drifting with the
wind, this track quickly drifts upwind relative to you and the airmass
(which are drifting downwind). Therefore the next time around your circle,
the track will not have much relevance. The only thing that matters (as you
have said) is the glider relative to the airmass, which the GPS cannot
accurately track and plot. That relationship has to be inertially derived,
or simple inferred to be static. The GPS plot is relative to the earth,
which can be thought of as moving underneath you at the speed of the wind.
Such a plot is of little value when thermaling though they can be useful for
ridge and wave, which are effectively anchored to the earth.

There have been some attempts to guess the drift of the thermal from an
assumed or calculated wind speed, but most thermals where I fly are not so
well behaved.

jfitch

August 13th 13, 05:13 PM

On Monday, August 12, 2013 8:49:40 AM UTC-7, Dan Marotta wrote:
> Thanks - now I see what you mean. My confusion was because XCSoar does a
>
> pretty good job of predicting the wind drift (due to getting good
>
> information from my CAI302) and so the flight track (rather than ground
>
> track) is displayed while circling. This makes it pretty easy to get back
>
> to the lift if, due to inattention or poor decisions, you get out of it.
>
>
>
> Slightly off topic, but IIRC I can set up the software so that it accounts
>
> for wind drift while circling and not in straight flight. I say this
>
> because I use the track to stay in the best lift while wave flying.
>
>
>
>
>
>
>
> ...
>
> On Sunday, August 11, 2013 10:19:40 AM UTC-7, Dan Marotta wrote:
>
> > What are you trying to say. Seems to me that the airmass is carrying the
>
> >
>
> > thermal along and the glider with it. With that premise, circling in calm
>
> >
>
> > air or in a wind makes no difference. I've thermalled straight up and
>
> > with
>
> >
>
> > a 20+ kt drift down wind. I never had to hold heading into a wind to
>
> >
>
> > maintain center in a thermal.
>
> >
>
> >
>
> >
>
> > Or do I misunderstand what you're saying? If that's the case, please
>
> >
>
> > elaborate.
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> > ...
>
> >
>
> > > On Saturday, August 10, 2013 8:43:05 AM UTC-7, Dan Marotta wrote:
>
> >
>
> > >> Your glider is drifting with the wind, too...
>
> >
>
> > >>
>
> >
>
> > >>
>
> >
>
> > >
>
> >
>
> > >
>
> >
>
> > > Unfortunately, the earth, and the GPS system that tracks with it, is
>
> >
>
> > > not.....
>
>
>
> It makes a difference if you are trying to relate your thermaling track to a
>
> track projected to the ground. Some thermal assistants (like SYM) draw a
>
> track on the ground color coded by climb rate. If you are drifting with the
>
> wind, this track quickly drifts upwind relative to you and the airmass
>
> (which are drifting downwind). Therefore the next time around your circle,
>
> the track will not have much relevance. The only thing that matters (as you
>
> have said) is the glider relative to the airmass, which the GPS cannot
>
> accurately track and plot. That relationship has to be inertially derived,
>
> or simple inferred to be static. The GPS plot is relative to the earth,
>
> which can be thought of as moving underneath you at the speed of the wind..
>
> Such a plot is of little value when thermaling though they can be useful for
>
> ridge and wave, which are effectively anchored to the earth.
>
>
>
> There have been some attempts to guess the drift of the thermal from an
>
> assumed or calculated wind speed, but most thermals where I fly are not so
>
> well behaved.

XCSoar does have the option to drift your track at the assumed wind speed to account for this problem. I have found it not to be accurate enough to make it usable (may depend on where you fly). The XCSoar thermal assistant does about the same thing as Winpilot, but the presentation is not as good: the correction arrow is inusfficiently scaled, the polar graph very blocky (if it is really plotting every 10 deg), no other information presented such as average or graphed climb, flarm targets, etc.

[email protected]

August 19th 13, 05:48 AM

I bit the bullet and purchased an Oudie 2. New system worked great and was very visible in somewhat darkened skies due to overcast. Thermal assistant seemed to be much improved with version 4.50.003. So long WinPilot/PDA. Thanks to Craggy Aero for their prompt service.

[email protected]

August 20th 13, 01:38 AM

On Thursday, August 1, 2013 3:20:49 PM UTC-7, Naviter Info wrote:

> I dare to say that accurate thermal assistants are a myth and that head down time during circling is a waste unless you are consciously learning a particular technique. At the same time - I do keep the "ding ding" thermal assistant active most of the time. Mainly because at times I become useless when I am talking on the radio, looking at my landing options or become plain old tired. That's when the thermal assistant's "ding ding" is usually right and very useful.
>
>
>
> Regards,
>
> Andrej Kolar
>

Thanks for the reworked thermal assistant Andrej. I do like the zoom/tracking feature as it allows me to explore a spread out area of lift and still return to the hotspot(s) with some reliability. It also allows me to account for wind drift a bit better.

I do think the arrow and beep in the climb optimization is still a bit irregular as it is sometimes seems 180-degrees out of sync from where the stronger lift turns out to be. I'm not sure how you are integrating the climb rates around 360 degrees, but it feels as though the arrow points to the strongest single 20- or 30-degree sector of lift rather than the direction to move the circle to maximize the rate of climb around the entire circle. I realize that with a choppy thermal it is easy to confuse any estimation algorithm, but there is something my brain does (and WinPilot seems to do) that still nets this out a bit better. I wonder if there are more parameters you could expose to allow some tuning to individual preferences. Lastly, an average climb line graph over the past 5-7 circles would also be welcome - I make due today with the 20 second averager versus the climb for the thermal, but a trend line would be more intuitive.

Again, nice improvements - I agree it is very useful in those cases where I have gone brain dead for a moment, but I also use it to speed coring thermals any time when I am unable to core on the first turn and a half - which is most of the time.

9B

Eric Greenwell[_4_]

August 20th 13, 09:55 PM

jfitch wrote, On 8/11/2013 9:59 PM:
> It makes a difference if you are trying to relate your thermaling
> track to a track projected to the ground. Some thermal assistants
> (like SYM) draw a track on the ground color coded by climb rate. If
> you are drifting with the wind, this track quickly drifts upwind
> relative to you and the airmass (which are drifting downwind).

The Thermal Assistant in my version of SYM does not draw a track on the
ground (of course, the map shows the ground track); instead, it opens
it's own window with no map info on it, and uses about 20 or so small
circles ("bubbles") arranged uniformly in a large circle to display the
thermal. Each bubble is sized and colored to depict the lift at that
point: bigger bubble, bigger lift; red is stronger, blue is weaker (the
actual colors can be selected)

In essence, your circles do overlay each other, no matter how much the
glider drifts with the wind. I never had trouble with wind drift when
using the Assistant. ClearNav, what I am now using, does use a ground
track, and it's hard for me to make sense of the the thermal is doing
from it's depiction. I'm nagging them about this, and I hope it will be
improved soon.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

jfitch

August 20th 13, 11:48 PM

On Tuesday, August 20, 2013 1:55:53 PM UTC-7, Eric Greenwell wrote:
> jfitch wrote, On 8/11/2013 9:59 PM:
>
> > It makes a difference if you are trying to relate your thermaling
>
> > track to a track projected to the ground. Some thermal assistants
>
> > (like SYM) draw a track on the ground color coded by climb rate. If
>
> > you are drifting with the wind, this track quickly drifts upwind
>
> > relative to you and the airmass (which are drifting downwind).
>
>
>
> The Thermal Assistant in my version of SYM does not draw a track on the
>
> ground (of course, the map shows the ground track); instead, it opens
>
> it's own window with no map info on it, and uses about 20 or so small
>
> circles ("bubbles") arranged uniformly in a large circle to display the
>
> thermal. Each bubble is sized and colored to depict the lift at that
>
> point: bigger bubble, bigger lift; red is stronger, blue is weaker (the
>
> actual colors can be selected)
>
>
>
> In essence, your circles do overlay each other, no matter how much the
>
> glider drifts with the wind. I never had trouble with wind drift when
>
> using the Assistant. ClearNav, what I am now using, does use a ground
>
> track, and it's hard for me to make sense of the the thermal is doing
>
> from it's depiction. I'm nagging them about this, and I hope it will be
>
> improved soon.
>
>
>
> --
>
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
>
> email me)
>
> - "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
>
> http://tinyurl.com/yb3xywl

The latest version of SYM draws a color coded ground track, as well as the bubbles. Still has quite a ways to go to catch up with what Winpilot had in 2005....