"Blunkett u-turn on data privacy plans"

[Roland Perry]

In message <1165392191-7086274@espace.net>, Fearghas McKay
<fm-lists@st-kilda.org> writes

>no not normal GPS receivers - two antenna and a specialised box that
>compares the difference.
>
>>And you can detect a difference of 100 microns? Surely that would
>>require each receiver to have a readout significant to 100 microns, even
>>assuming they drifted and wobbled absolutely in time with one another.
>
>>From the conversations I have had with the marine engineers on this I think
>that it is not impossible but I don't have source material to verify it.

There's another list I'm on that recently carried the observation:

        "I am confused" in ITU-T speak means "You are talking bull****".

I have to say that I'm still *very* confused about the 100 micron
claims.

However, my practical experience and what I've read says that yes, I
would believe that a suitable receiver could easily detect relative
yaw/pitch movements of a ship of the order of a few cm (and back) at
relative speeds of a few cm per second. Especially if using doppler
enhancement:

http://www.racelogic.co.uk/vbox/gps.htm

-- 
Roland Perry