[time-nuts] HP 58503A

[bg at lysator.liu.se]

Doug,

> I ran into a wiki description of GPS using WGS84 a couple days ago. It
> included a mention of ESEC and it was something like: Earth Static,
> Earth Centric. I think I was following a link about the Z3801A.
>
> It referred to the fact that lat-lon is referenced to a static grid on
> the Earth and doesn't change as the Earth rotates on its axis or around
> the sun. Earth static and Earth centric.

That reference frame is called Earth Centered Earth Fixed  (ECEF). And
that is what GPS is using "internally". However it is not lat/lon/h, but
cartesian with origo in the earth center, xy in the equatorial plane and z
pointing towards the north pole.

    http://en.wikipedia.org/wiki/ECEF

--

   Björn