[OSRS-PROJ] gauss-krueger/transverse mercator

[Andreas Lange]

Hi,

i verified all the values for the german system and for the
german/middle european range the values displayed on the receiver and
calculated from my program are identical (to ca. 10 m, what is
sufficient).

But my problem is that the GPS receiver gives readings for the other
range as noted below too. I don't think that these values are the result
of internal overflow from the device, as this would be very dangerous
(and garmin should be aware of such problems). 

The communication with the device is only via lat/lon in the wgs84 datum
(no zone data needed in lat/lon), all values must be converted on the
computer via software. And this gives the problem that if the device
displays a reading, i can not set this to an error in my software, as
the device and the uploaded data would be inconsistent in this case. If
the user accidently uploads or downloads data, the data for the
non-european range would be lost. 

Thanks for your comments so far, maybe i will contact garmin with the
questions. 

yours,

Andreas Lange


Gerald I. Evenden wrote:
> 
> In some instances, I have heard that GK (Gauss_Kruger) only applied to
> 5 zones centered on 3E, 9E, 15E, ... ---European coverage.  Regarding
> the German grid you mentioned, it seems strange to use 500,000m easting
> when the zones are only 3 degrees wide, half the GK/UTM width.
> 
> Any reading where the easting exceed 500,000m is obviously seriously
> in error and/or the wrong zone (CM) was specified.  Same if the easting
> is negative.
> 
> Incidentally, are you capable of specifying the zone number to the Garmin?
> Seems to me that would be required especially when you are on the seam
> between zones and can use either.
> 
> As for southern latitudes and GK, I have never heard, but I would think
> that 10,000,000m false northing would apply.  If it is labelled as a German
> system, then southern latitudes don't apply so why bother with a false
> northing.
> 
> A trouble with the Gauss-Kruger nomenclature is that it means two
> different things:
> 1) a method of computing the transverse Mercator projection
> 2) a coordinate system identical to UTM except for zone numbering
> 
> >From your description of the "German" grid system, this is not
> >
> > The receiver gives me the following readings:
> > lat    lon     easting/northing
> > 29.27N 10.5W   5436500/5815100 (??)
> > 29.27N 10.5E   4354200/3240000 (ok)
> > 29.27N 18.83E  5579200/1675000 (??)
> > 29.27N 18.83W  5923300/9718000 (??)
> > 85.44N 18.83E  5009100/0035000 (??)
> > 85.44N 18.83W  5923000/9718000 (??)
> >
> > Are those values (??) only an internal overflow of the receiver?
> >

-- 
Andreas Lange, 65187 Wiesbaden, Germany, Tel. +49 611 807850
Andreas.Lange at Rhein-Main.de, A.C.Lange at GMX.net

----------------------------------------
OSRS PRoject PROJ Discussion List
To Subscribe: send a message to majordomo at remotesensing.org with 'subscribe osrs-proj' in the body
To Unsubscribe: send a message to majordomo at remotesensing.org with 'unsubscribe osrs-proj' in the body
To Report Problems: send a message to owner-osrs-proj at remotesensing.org