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

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.