[GRASS-dev] [GRASS GIS] #2229: error in projection definition

GRASS GIS trac at osgeo.org
Thu Mar 24 13:25:42 PDT 2016


#2229: error in projection definition
---------------------------------+---------------------------------
  Reporter:  vincent             |      Owner:  grass-dev@…
      Type:  defect              |     Status:  new
  Priority:  normal              |  Milestone:  7.0.4
 Component:  Projections/Datums  |    Version:  svn-releasebranch70
Resolution:                      |   Keywords:
       CPU:  Unspecified         |   Platform:  Unspecified
---------------------------------+---------------------------------

Comment (by vincent):

 To me the issue is still the same, except that it may not be a grass-
 specific one.
 On a fresh grass7 (r68135) install :
 - Create a new pseudo-mercator location with loc'n wiz by selecting epsg
 code 3857
 - Pick "0" from datum transformations list ("do not apply any datum
 transformations")
 - Then execute :

 {{{
 m.proj -o -d coordinates=720000,5740000
 6.46787005|45.93986903|0.00000000
 }}}


 - regarding this result execute :

 {{{
 echo "6.46787005 45.93986903" | cs2cs +init=epsg:4326 -f "%.8f" +to
 +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0
 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs
 720000.00048307 5770718.42069077 0.00000000
 }}}

 There is a north-south error of approx. 30 km;
 It looks like m.proj sends "+rf=298.25..." to cs2cs, where it shoud not...

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/2229#comment:8>
GRASS GIS <https://grass.osgeo.org>



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