Jimmy (Jimbo) Wales wrote:
Just out of curiosity, how will the GPS co-ordinates differ in the Galileo system from the existing system? I assume that the two can be easily converted back and forth, or that the numbers are the same for both?
If the numbers differ, we should accept both, so the markup should have the ability to distinguish. It'd be a shame if I took my GPS receiver (which uses the existing system) to get a location, but could not enter it. It would be equally a shame if someone took a Galileo system out in a few years and could not easily enter that as well.
--Jimbo
Both Galileo and the GPS use the International Terrestrial Reference System as their reference frame, and TAI as their reference timescale. They then derive their own realizations of these idealized systems using their own infrastructure. Although the Galileo and GPS realizations of the ITRS and TAI will be independent, they should match to within a resolution of a few centimeters or nanoseconds respectively, and so should be effectively interchangeable for most low-resolution use.
See http://www.galileosworld.com/galileosworld/article/articleDetail.jsp?id=7561... and http://www.iers.org/iers/earth/itrs/itrs.html for more details.
-- Neil