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

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) he

http://www.naviter.com/2013/08/new-v...and-new-logos/



There's also a discussion on a same/similar topic he

http://forum.naviter.com/threads/494...-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!

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!

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.

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. .

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?)

No. You got that backwards....

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?)

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

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

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.