Ed,
The really cheap receivers use a single channel receiver multiplexed to
each
different satellite, in turn.  This limits the maximum ground speed they
can display
with accuracy.  The more expensive ones, and the aviation units have
parallel
channel receivers (Garmin uses 12 channels), which processes each
satellites signals
in parallel, allowing much greater ground speed with accuracy.  The main
difference,
other than that, is in the bells and whistles; things such as waypoints,
mapping,
databases, etc.  The GPS format consists of two signals, the rough
alignment signal
(if memory serves, called L1) and the precision signal, called L2
available only to
the military and other qualifying government agencies.  What we use is the
L1
signal.  What the gov't did was turn off a slight dithering of the timing
signals
which randomly degraded the position accuracy.  What we are getting now is
the full
accuracy of the non-precision signal.  The full-up military GPS units can
give
positions accurate to within a few inches.  Anyway, the Readers Digest
version is
that any civilian GPS unit is capable of full accuracy, within the
groundspeed
constraints.
Dave in Alamogordo, NM

Ed Burkhead wrote:

> I've been wondering if the cheap end of the GPS receivers have the
ability to
> handle the higher quality signal.
>
> Anyone have any ideas?
>
> --
> Ed Burkhead
> Peoria, Ill.
> Ercoupe N3802H, 415-D
>
> Never open an attachment with a ".exe" or ".com" or ".vbm" suffix.
> To be safe, turn off Microsoft's Visual Basic Macro execution option.
> Consider not using Outlook for mail - lots of viruses target its
security
> flaws.
>
__________________________________________________________________________
______
> To unsubscribe from this list please send
mailto:[EMAIL PROTECTED]
> ___________________________________________________________
> T O P I C A  The Email You Want. http://www.topica.com/t/16
> Newsletters, Tips and Discussions on Your Favorite Topics

__________________________________________________________________________
______
To unsubscribe from this list please send
mailto:[EMAIL PROTECTED]
___________________________________________________________
T O P I C A  The Email You Want. http://www.topica.com/t/16
Newsletters, Tips and Discussions on Your Favorite Topics

<<attachment: winmail.dat>>

Reply via email to