[postgis-tickets] [PostGIS] #1851: Wrong parameters for EPSG:3844 in spatial_ref_sys

[PostGIS]

#1851: Wrong parameters for EPSG:3844 in spatial_ref_sys
----------------------+---------------------------
  Reporter:  gix      |      Owner:  pramsey
      Type:  defect   |     Status:  reopened
  Priority:  medium   |  Milestone:  PostGIS 2.0.1
 Component:  postgis  |    Version:  2.0.x
Resolution:           |   Keywords:
----------------------+---------------------------
Changes (by tudorbarascu):

 * status:  closed => reopened
 * resolution:  fixed =>


Comment:

 Actually, r9853 introduced bigger errors because the coordinate
 transformation parameters given by the Romanian National Agency for
 Cadastre and Land Registration ( http://www.ancpi.ro ) are given for the
 Coordinate Frame Rotation method (https://epsg.io/9607-method)
 and as proj4 uses the https://epsg.io/9606-method (Position Vector
 transformation) the sign of the rotation parameters needs to change so
 that it works in proj4 as referenced at
 http://proj.maptools.org/gen_parms.html

 This is clear from the EPSG database.
 {{{
 SELECT c.coord_op_name, c.coord_op_method_code, a.parameter_value,
 b.parameter_name
  FROM epsg_coordoperationparamvalue a LEFT JOIN epsg_coordoperationparam b
 ON a.parameter_code = b.parameter_code
  LEFT JOIN epsg_coordoperation c on a.coord_op_code = c.coord_op_code
  WHERE a.coord_op_code = 15994;
          coord_op_name          | coord_op_method_code | parameter_value |
 parameter_name
 --------------------------------+----------------------+-----------------+--------------------
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |          2.3287 |
 X-axis translation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |       -147.0425 |
 Y-axis translation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |        -92.0802 |
 Z-axis translation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |       0.3092483 |
 X-axis rotation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |     -0.32482185 |
 Y-axis rotation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |     -0.49729934 |
 Z-axis rotation
  Pulkovo 1942(58) to ETRS89 (4) |                 9607 |      5.68906266 |
 }}}

 So, the correct parameters should be:
 {{{
 +towgs84=2.3287,-147.0425,-92.0802,-0.3092483,0.32482185,0.49729934,5.68906266
 }}}

 and not as it's now in Postgis - with incorrect rotation parameters
 {{{
 +towgs84=2.329,-147.042,-92.08,0.309,-0.325,-0.497,5.69
 }}}

 As I am not at all familiar with SVN, can someone with commit rights can
 make the appropriate changes.
 If you think it would be better for me to do this I will study how to do
 it and make a.. pull request
 Thanks a lot!
 Tudor

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/1851#comment:3>
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