[LinuxPPS] time compensation

[clemens at dwf.com]

> Sorry I disagree completely, but I think subsequent posts have shown
> that 'coax' delay is not significant in the scheme of things.

Let me explain the logic as I see it.

The important point (that is the point where the position is computed, or
the time reckoned) is the antenna.

This is where the variable length paths from the several satellites is combined.
Now you can have zero, or miles of cable from that point on, and it will
do nothing but delay the signal, it will not change the time differences 
from the various satellites.  It is the combined signal that is important,
and not the delay in the cable,- you could record the signals as they 
come into the antenna and play them back later and you would still
get the same time.  The cable delay then is just that, if you had a mile
of cable, you would expect to receive the signals later than if you had
the receiver right at the antenna.  So with a reasonable amount of
cable you are computing the time AT THE ANTENNA, but then must
compensate for the fact that you saw this signal at a later time due
to the length of the cable.

Hope that helps.

-- 
                                        Reg.Clemens
                                        reg at dwf.com