[OSM-talk] Garmin eTrex Vista Hcx

[Paul Houle]

John F. Eldredge wrote:
> The GPS in my car is a Garmin (I don't recall the exact model at the moment).  It appears to be much more accurate when the car is in motion than when the car is stationary.  If I power the GPS up with the car stationary, the location given can be inaccurate by 100 meters or more.  Once the car starts to move, the GPS can locate the car within 3 or 4 meters.
>
>   
    In automotive applications,  GPS Units often use a 'snap to road' 
that makes them look a lot more accurate.

    My eTrex Vista HCX has two modes of computing headings:  one of them 
is to (i) look at the direction your track is going in and the other is 
a (ii) built-in magnetic compass.  If I'm moving,  either in a vehicle 
or on foot,  I find (i) more satisfying than (ii).

    The most obnoxious thing about altitude on my eTrex is that I don't 
see how to get it to use GPS altitude instead of barometric altitude.  
(I know how to pop up a dialog box to ~view~ GPS altitude,  but that's 
it.)  Barometric altitude is totally useless if you're inside a 
pressurized airplane.  ;-)

    In most situations repeatability is pretty good for me;  I use 
tracks for "breadcrumb navigation" all of the time on foot and rarely 
see anomalies that cause practical problems.  I circumnavigated the BWI 
airport during a layover the other day and got at the the terminal 
within 3 minutes of when I thought I would,  using GPS data as the major 
input to my mental calculation.

    Now,  I did get lost in the tunnels of the Library of Congress the 
day before that...  I just need an inertial guidance system for 
situations like that.