Portable computers and GPS

[Julian Humphries]

>
>    There seem to be 3 popular GPS systems in use here in
>Australia.  We use units sold by Magellan (models 1000 Plus and
>5000).  I have one and have used it extensively with no problems.
>The unit lacks a direct computer link, but will store 100
>"waypoints" (= localities) internally and is repeatable within 2
>seconds lat/long.  It is small, robust, runs off batteries
>(including both standard and recharable), and floats if you
>happen to drop it in water.  The other common models used here
>are sold by ProNav and Trimble.  I haven't used them so I can't
>say much, but they seem to be basically the same as the Magellan
>system.  We purchased our systems from a marine supply house and
>they has several models in stock for use to play with, so you may
>be able to try before you buy.  I know of one person using the
>Sony GPS system, but he has had trouble getting consistantly
>repeatable locality results (varaitions of up to several minutes
>at the same place over a few days time) and was disappointed with
>the mechanical robustness of the system compared to the other
>systems listed above (he got it because it was cheaper than other
>systems).


Can some explain some of the specifications for these units and whether we
should have concern about any of them:

4/5/6 channel technology (sometimes stated as "parallel")
NMEA 0183 version 2.00, or 0183/180 interface
Do all units show elevation/altitude?
Number of lines of LED display
Do any units differ in time to get original reading (how long is this?)
Is the Magellan the only waterproof unit?

I have pricing as follows (US dollars) Are these good prices?  Does anyone
else have other dealers (e.g. mailorder) or access to spec's on other
brands?

Sony Pixar  $600   (Tiger Software)
Motorola Traxar Handheld GPS $900  (Cabela's)
Magellan 5000D $995  (Cabela's)

Julian Humphries
The Vertebrate Collections and The MUSE Project, Cornell University
Building 3, Research Park
83 Brown Road
Ithaca, NY  14850

Voice: 607-257-8143
Fax:   607-257-8109
Email: jmh3 at cornell.edu