Opened 11 years ago

Closed 9 years ago

#2590 closed defect (fixed)

South orientated transverse mercator support lacking.

Reported by: quartex Owned by: warmerdam
Priority: normal Milestone:
Component: OGR_SF Version: unspecified
Severity: normal Keywords:
Cc: craigleat

Description

None of the TMSO projections are handled by OGRSpatialReference, or PROJ.4. eg. EPSG:2054.

TMSO is apparently just TM with the y coordinate reversed for sign.

sample point to follow...

Change History (7)

comment:1 in reply to:  description Changed 11 years ago by quartex

Replying to quartex:

None of the TMSO projections are handled by OGRSpatialReference, or PROJ.4. eg. EPSG:2054.

TMSO is apparently just TM with the y coordinate reversed for sign.

sample point to follow...

Replying to quartex:

None of the TMSO projections are handled by OGRSpatialReference, or PROJ.4. eg. EPSG:2054.

TMSO is apparently just TM with the y coordinate reversed for sign.

sample point to follow...

Here is the point:

LatLong? (Hartebeesthoek 94 - EPSG 4148) x: 30.35212704 y: -29.62346472

Projected (# Hartebeesthoek94 / Lo31 - EPSG 2054) x: -62746.176430242 y: -3278550.09187

And here is the prj format from ArcGIS:

PROJCS["Hartebeesthoek 31",GEOGCS["GCS_Hartebeesthoek_1994",DATUM["D_Hartebeesthoek_1994",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTIONTransverse_Mercator?,PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",31.0],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]]

comment:2 Changed 11 years ago by warmerdam

I am confused I tried the following, and it appears the test point works with plain transverse mercator. Also, the ESRI coordinate system description just shows "Transverse Mercator", nothing special about it being south oriented at all.

cs2cs +proj=latlong +datum=WGS84 +to +proj=tmerc +lon_0=31 +datum=WGS84
30.352 -29.623
-62758.77       -3278498.65 0.00

Could you review and ensure that this is really an appropriate coordinate system and .prj file?

comment:3 in reply to:  2 Changed 11 years ago by quartex

Perhaps this is easier than assumed. Essentially the Hartebeesthoek is a modified WGS84 datum. Transverse Mercator is still used. The full description is found here: http://www.gpswaypoints.co.za/FAQ_world_geodetic_system_1984.

comment:5 Changed 10 years ago by craigleat

Cc: craigleat added

Lack of support for TMSO is affecting users of proj, gdal, ogr, grass, qgis and possibly other projects. A wiki page is available for discussion and co-ordination of efforts. It is hoped that this will lead to a satisfactory implementation in the near future.

http://trac.osgeo.org/proj/wiki/TMSO

comment:6 Changed 10 years ago by craigleat

Axis orientation control has been added to PROJ.4, see: http://trac.osgeo.org/proj/ticket/18#comment:3

I tried the following:
$ ogr2ogr -t_srs "+proj=tmerc +ellps=WGS84 +datum=WGS84 +lat_0=0 +lon_0=31 +x_0=0 +y_0=0 +k_0=1 +axis=wsu" -f "ESRI Shapefile" DC22_LMs_Hartebeesthoek94-Lo31.shp DC22_LMs_LatLong.shp

In the resulting .prj file the WKT is standard tmerc. I loaded the shapefile into QGIS and the co-ordinates are still negative as for standard tmerc.

comment:7 Changed 9 years ago by warmerdam

Resolution: fixed
Status: newclosed

Support for proj.4 translation and validation of tmso projections added in gdal trunk (r20163).

Note: See TracTickets for help on using tickets.