Calculating Headwind/Tailwind component

On Mar 14, 12:04*pm, Ramy wrote:

Not only it isn't meaningless, but it is very meaningful.

[snip]

I agree, perhaps I was just soft pedaling.

There's much to be improved in wind calculation using GPS and TAS even
without resorting to magnetic compass inputs. I've been working on
better algorithms, which I test using recorded nmea from actual
flying, including ridge, wave & thermals. I find that the 302
component wind works really well. It's robust, reliable and rapid.
The vector wind, well, not so much. I have an algorithm in manual
spreadsheet form that flat out eats the 302's lunch for vector wind
using the same nmea and I've promised (but not yet delivered) a brief
to JW on this (it's better than XCS' wind calculation too). If he
likes it, perhaps we can make some improvements in XCS.

Another thing that may happen sooner is using the component wind to
sanity check XCS' vector wind and report a figure of merit of some
sort.

-Evan Ludeman / T8

I recall seeing an OSTIV paper, by someone from New-Zealand if I'm correct, where
the wind vector was derived from just the pitot and GPS. Using multiple pitot/GPS
combinations, the most likely wind direction was estimated.
The paper used data from the perlan project as an example. The more deviations in
course, the better the result was. Appeared quite promising to me.

Roel

On Wednesday, March 14, 2012 10:44:06 AM UTC-7, Roel Baardman wrote:
I recall seeing an OSTIV paper, by someone from New-Zealand if I'm correct, where
the wind vector was derived from just the pitot and GPS. Using multiple pitot/GPS
combinations, the most likely wind direction was estimated.
The paper used data from the perlan project as an example. The more deviations in
course, the better the result was. Appeared quite promising to me.

Roel

Thanks for all the explanations and opinions. I understand that more complex math and data is required to calculate wind vectors precisely. However I am looking for a conclusion about the value of the simple math of TAS-GS, and why it is not suitable as a valuable information in a flight computer. I have been using this for years to determine if and by what magnitude the wind is helping my final glide and my arrival time, or working against me. No complex math, just common sense. Perhaps calling it head wind component is not accurate, so I am open for better definition. Regardless how we call it, I have no doubt it is very valuable, more accurate and more instantaneous then the often inaccurate calculated wind vector, and thus should be included in flight computers. I believe LK8000 calculates HW, I am curious to hear if it is derived from wind vector or TAS-GS.

Ramy

On Mar 14, 5:28*pm, Ramy wrote:
On Wednesday, March 14, 2012 10:44:06 AM UTC-7, Roel Baardman wrote:
I recall seeing an OSTIV paper, by someone from New-Zealand if I'm correct, where
the wind vector was derived from just the pitot and GPS. Using multiple pitot/GPS
combinations, the most likely wind direction was estimated.
The paper used data from the perlan project as an example. The more deviations in
course, the better the result was. Appeared quite promising to me.

Roel

Thanks for all the explanations and opinions. I understand that more complex math and data is required to calculate wind vectors precisely. However I am looking for a conclusion about the value of the simple math of TAS-GS, and why it is not suitable as a valuable information in a flight computer. I have been using this for years to determine if and by what magnitude the wind is helping my final glide and my arrival time, or working against me. No complex math, just common sense. Perhaps calling it head wind component is not accurate, so I am open for better definition. Regardless how we call it, I have no doubt it is very valuable, more accurate and more instantaneous then the often inaccurate calculated wind vector, and thus should be included in flight computers. I believe LK8000 calculates HW, I am curious to hear if it is derived from wind vector or TAS-GS.

Ramy

In a no-wind situation, TAS = GS, so TAS - GS = head (or tail wind)
component. What's the proplem? Remember that TAS will decrease as you
get lower and the GS is tied to the track you were making good at the
time you read your GS.
JJ
USAF Nav/bomb School 1960 & 1961