Scanning maps and GRASS

Simon Cox S.Cox at solo.ned.dem.csiro.au
Fri Nov 10 07:00:00 EST 1995


At 1:56 PM 9/11/95, Casey Claiborne wrote:
>Should I stamp my foot
>down and say that I want 300 dpi?

Yes - because more than likely when you are digitising (or analysing)
later you will want to zoom, etc.

The person you are talking to is probably fed up with nongs who
overdo it and blow out file sizes.  For GIS applications one must
always consider the necessary precision _on_the_ground_, and what this
translates to in terms of dimensions on the paper map that you are scanning.
So, 5m on a source map at 1:50,000, is represented by 0.1mm or 1/254 of an
inch,
etc etc

Simon Cox

___________________________________________________________
Dr Simon Cox                          __  \
CSIRO Exploration & Mining         ,~'  L_|\    Australian
39 Fairway, PO Box 437,         ;-'         \   Geodynamics
Nedlands, WA  6009  Australia   (            \  Cooperative
      Phone +61 9 284 8443      +    ___     /  Research
      Fax   +61 9 389 1906       L~~'   "\__/   Centre
simon at ned.dem.csiro.au                     W
AGCRC info>>   http://www.ned.dem.csiro.au/AGCRC/
___________________________________________________________







More information about the grass-user mailing list