"d&tm" wrote in message
...

"Chad Speer" wrote in message
oups.com...
Terry - thanks for the reply, but heading is not known.

snip

TAS1^2=WS^2+GS1^2-2WSGS1COS(180-ABS(WD-TR1)
TAS2^2=WS^2+GS2^2-2WSGS2COS(180-ABS(WD-TR2)

WHERE TAS1 AND TAS2 ARE TRUE AIRSPEEDS FOR AIRCRAFT 1 AND 2
WS = WIND SPEED
WD =WIND DIRECTION IN DEGREES MAG
TR1 AND TR2 ARE TRACKS MAGNETIC FOR AIRCRAFT 1 AND 2
GS1 AND GS2 ARE GROUND SPEEDS FOR AIRCRAFT 1 AND 2.
(180-ABS(WD-TR) WILL GIVE YOU THE ACTUAL ANGLE BETWEEN WIND DIRECTION AND
TRACK.

Now we have 2 equations with 2 unknowns ( WS and WD) which should be
solvable but I am stuggling to get it out. However I did a little
exercise
which suggests the end result may not be very useful. because small errors
in the ground speeds will cause very large errors in the calculated wind
speed.

I think the head/tail wind portion of the estimate should be pretty good,
but the crosswind component would have so much error as to be useless. We
need a way to use the head/tail wind components from different airplanes,
flying different headings and NOT use the less acurate crosswind estimates.
I think a Kalman filter would work.

Danny Deger