Originally Posted by Rushed Approach
My understanding of aircraft "groundspeed" is the component of tangential speed at right angles to a radius drawn from the centre of the Earth, averaged over the distance of the route.
That's the Kayton definition.
Originally Posted by italia458
I complete agree with your definition of groundspeed in the last paragraph!
Good, because in
this post from the 26th June you chose the other interpretation.
Yes, 6 pp. For those not here at the beginning, it ran as follows. ATCast pointed out there were two non-equivalent definitions of groundspeed and asked for clarification. I found out that navionics engineers use the "tangential speed" definition (aka TAS corrected for wind speed) by looking it up in Kayton and Fried, Avionics Navigation Systems, 2nd edition, Wiley-Interscience 1997 where it may be found in Sectiona 2.2 to 2,4, in particular Figure 2.4; Genghis pointed to a
paper by Guy Gratton on calibration which used a similar definition. LH2 supplied the further references
Originally Posted by LH2
[1] M. Grewal et al. "Global Positioning Systems, Inertial Navigation, and Integration", 2nd ed., Wiley Interscience, New Jersey, 2007, p31.
[2] R. Rogers, "Applied Mathematics in Integrated Navigation Systems", 3rd ed., AIAA, Blacksburg VA, 2007, p105.
[3] Grewal, p92-93
[4] A. Leick, "GPS Satellite Surveying", 2nd ed., Wiley Interscience, 1995, p487.
in
this interesting post
Newcomers might want to take a look at these references.
People weighed in with their "favorite" definition (one of the two), or for an ambiguous statement.
I had some interesting discussion with LH2 and ft about technical subtleties, inter alia to do with how one determines which way is "down" (there are at least three non-equivalent definitions). Others have their own ideas about what constitutes "interesting", not necessarily similar.
Is there anything else to say?
PBL