From: James R. Cunningham
> Out of idle curiosity I took my Garmin 92 into Memphis with me this
morning.
> During a 25 mile drive, with decent reception on 8-10 satellites, EPE
ranged
> between 11-14 feet with an occasional excursion to 39 feet.  Among the
> downtown buildings, with 6-8 satellites, EPE was about 22-25 feet with an
> occasional excursion to 41 feet.  I sat on a bench for about 10 minutes
with
> 6 satellites, EPE was 24-25 feet, and Altitude varied by about 10 feet
with
> maximum excursions of 50 feet.   The excursions took about 10-15 seconds
and
> occurred about once every 2-4 minutes.
>
> Jim

The error number you see is not related to the presence or absence of SA,
that
error number is related to the accuracy of your solution from the geometry
of the SVs (the smaller the included angle of all the SVs in your solution,
the larger the error will be).  The excursions you see are probably due to
SVs
being switched in and out of your position solution.

Matt Bennett