Incorrect Datum Shift

Always use WGS84 as the primary datum

Central La Plata, PR, 1:24:000 DEM and DLG
  • Both digitized on NAD27
  • Displayed on WGS84
  • DEM correctly shifted
  • DLG not shifted.  MICRODEM does not perform a datum shift on DLGs, so in this case you should display on NAD27 (or get an alternate source of streams, like TIGER data).
  • Note the large N-S offset--the streams are about 200 m too far to the south, as are the quad boundaries included in the streams DLG.
Central La Plata, PR, 1:24:000 DEM and DLG
  • Both digitized on NAD27
  • Displayed on NAD27
  • Correct registration

Last revision 6/5/2007