absolute velocity calculation

yann

in BFC, tha absolute velocity is computed by STORE(VABS)

but in ground , i coded my own definition VABS= SQRT( UCRT**2 + VCRT**2 + WCRT**2)

i think the built in definition is the same. if i make the contour of the ratio of the 2 definition , it appears surprisingly not equal to 1 but between 0.8 and 1.2 ... i think the difference is very important

where does it come from?? it is the right definition of VABS ? such as coded in the built in option of phoenics?

i made the test on the case B551 ....

thanks