Opened 13 years ago

Closed 5 years ago

#1520 closed defect (fixed)

Difficulty representing three Double_Stereographic projections in PROJ4 Format

Reported by: cmichaelis@… Owned by: warmerdam
Priority: normal Milestone:
Component: OGR_SRS Version: unspecified
Severity: normal Keywords: Double_Stereographic
Cc:

Description (last modified by warmerdam)

Hi there,

I'm having a hard time representing three projections in PROJ4 format. When I try to do so (e.g., using a simple conversion like the one posted at http://lists.maptools.org/pipermail/proj/2001-October/000258.html) I always get a vast (and erroneous) simplification of the projection down to "+ellps=GRS80 +units=m +no_defs" or something similar.

Is it possible to represent these in PROJ4 format using OGR?

1) ATS 1977 New Brunswick Stereographic
PROJCS["ATS_1977_New_Brunswick_Stereographic",GEOGCS["GCS_ATS_1977",DATUM["D_ATS_1977",SPHEROID["ATS_1977",6378135,298.257]],PRIMEM["Greenwich",0],UNIT["Degree",0.0174532925199432955]],PROJECTION["Double_Stereographic"],PARAMETER["False_Easting",300000],PARAMETER["False_Northing",800000],PARAMETER["Central_Meridian",-66.5],PARAMETER["Scale_Factor",0.999912],PARAMETER["Latitude_Of_Origin",46.5],UNIT["Meter",1]]

2) NAD 1983 CSRS98 New Brunswick Stereographic
PROJCS["NAD_1983_CSRS98_New_Brunswick_Stereographic",GEOGCS["GCS_North_American_1983_CSRS98",DATUM["D_North_American_1983_CSRS98",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.0174532925199432955]],PROJECTION["Double_Stereographic"],PARAMETER["False_Easting",2500000],PARAMETER["False_Northing",7500000],PARAMETER["Central_Meridian",-66.5],PARAMETER["Scale_Factor",0.999912],PARAMETER["Latitude_Of_Origin",46.5],UNIT["Meter",1]]

3) NAD 1983 CSRS98 Prince Edward Island
PROJCS["NAD_1983_CSRS98_Prince_Edward_Island",GEOGCS["GCS_North_American_1983_CSRS98",DATUM["D_North_American_1983_CSRS98",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Double_Stereographic"],PARAMETER["False_Easting",400000.0],PARAMETER["False_Northing",800000.0],PARAMETER["Central_Meridian",-63.0],PARAMETER["Scale_Factor",0.999912],PARAMETER["Latitude_Of_Origin",47.25],UNIT["Meter",1.0]]

Any help or feedback would be greatly appreciated. I posted this in component OGR_SRS, if it belongs in the PROJ bugzilla I beg forgiveness.

Thanks!
--Chris

Change History (4)

comment:3 Changed 13 years ago by warmerdam

Description: modified (diff)
Milestone: 1.5.0
Priority: highestnormal
Severity: blockernormal
Status: newassigned

comment:4 Changed 13 years ago by warmerdam

Keywords: Double_Stereographic added
Milestone: 1.5.0
Summary: Difficulty representing three OGR WKT projections in PROJ4 FormatDifficulty representing three Double_Stereographic projections in PROJ4 Format

dropping this from 1.5 milestone. It will be addressed as time permits and may require work in PROJ.4 as well.

comment:5 Changed 5 years ago by Jukka Rahkonen

With GDAL 2.1-dev Proj.4 strings are found for all these three projections. It they are correct I suppose that this ticket can be closed.

gdalsrsinfo epsg:2200

PROJ.4 : '+proj=sterea +lat_0=46.5 +lon_0=-66.5 +k=0.999912 +x_0=300000 +y_0=800
000 +a=6378135 +b=6356750.304921594 +units=m +no_defs '

OGC WKT :
PROJCS["ATS77 / New Brunswick Stereographic (ATS77)",
    GEOGCS["ATS77",
        DATUM["Average_Terrestrial_System_1977",
            SPHEROID["Average Terrestrial System 1977",6378135,298.257,
                AUTHORITY["EPSG","7041"]],
            AUTHORITY["EPSG","6122"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4122"]],
    PROJECTION["Oblique_Stereographic"],
    PARAMETER["latitude_of_origin",46.5],
    PARAMETER["central_meridian",-66.5],
    PARAMETER["scale_factor",0.999912],
    PARAMETER["false_easting",300000],
    PARAMETER["false_northing",800000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","2200"]]


gdalsrsinfo epsg:2953

PROJ.4 : '+proj=sterea +lat_0=46.5 +lon_0=-66.5 +k=0.999912 +x_0=2500000 +y_0=75
00000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs '

OGC WKT :
PROJCS["NAD83(CSRS) / New Brunswick Stereographic",
    GEOGCS["NAD83(CSRS)",
        DATUM["NAD83_Canadian_Spatial_Reference_System",
            SPHEROID["GRS 1980",6378137,298.257222101,
                AUTHORITY["EPSG","7019"]],
            TOWGS84[0,0,0,0,0,0,0],
            AUTHORITY["EPSG","6140"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4617"]],
    PROJECTION["Oblique_Stereographic"],
    PARAMETER["latitude_of_origin",46.5],
    PARAMETER["central_meridian",-66.5],
    PARAMETER["scale_factor",0.999912],
    PARAMETER["false_easting",2500000],
    PARAMETER["false_northing",7500000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AUTHORITY["EPSG","2953"]]


gdalsrsinfo epsg:2954

PROJ.4 : '+proj=sterea +lat_0=47.25 +lon_0=-63 +k=0.999912 +x_0=400000 +y_0=8000
00 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs '

OGC WKT :
PROJCS["NAD83(CSRS) / Prince Edward Isl. Stereographic (NAD83)",
    GEOGCS["NAD83(CSRS)",
        DATUM["NAD83_Canadian_Spatial_Reference_System",
            SPHEROID["GRS 1980",6378137,298.257222101,
                AUTHORITY["EPSG","7019"]],
            TOWGS84[0,0,0,0,0,0,0],
            AUTHORITY["EPSG","6140"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4617"]],
    PROJECTION["Oblique_Stereographic"],
    PARAMETER["latitude_of_origin",47.25],
    PARAMETER["central_meridian",-63],
    PARAMETER["scale_factor",0.999912],
    PARAMETER["false_easting",400000],
    PARAMETER["false_northing",800000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["E(X)",EAST],
    AXIS["N(Y)",NORTH],
    AUTHORITY["EPSG","2954"]]

comment:6 Changed 5 years ago by Jukka Rahkonen

Resolution: fixed
Status: assignedclosed

Closing this one because now it is easy to represent those three in proj4 format. If parameters are wrong it is worth another ticket.

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