Remarks: Parameters values from CH1903 to ETRS89 (1) (tfm code 1646) assuming ETRS89 and WGS 84 can be considered the same to within the accuracy of the transformation. Replaces CH1903 to WGS 84 (1) (code 1753). Replaced by CH1903 to WGS 84 (3) (code 7788).

Information source: Bundesamt für Landestopografie swisstopo; www.swisstopo.ch. Aufbau der Landesvermessung der Schweiz 'LV95' Teil 3: Terrestrische Bezugssysteme und Bezugsrahmen. L+T 1999. Also at Eurogeographics http://www.crs-geo.eu/ to 1dp precision.

Revision date: 2017-10-16

Attributes

Unit: metre

Geodetic CRS: CH1903

Datum: CH1903

Ellipsoid: Bessel 1841

Prime meridian: Greenwich

Data source: OGP

Information source: Bundesamt für Landestopografie swisstopo; www.swisstopo.ch

Revision date: 2015-11-25

Scope: Large and medium scale topographic mapping, cadastral and engineering survey.

Remarks: Replaces LV03C (CRS code 21780) in Switzerland, but used only occasionally in Liechtenstein. Replaced by CH1903+ / LV95 (CRS code 2056).

Method: Geocentric translations (geog2D domain)

Area of use: Liechtenstein; Switzerland.

Coordinate system: Cartesian 2D CS. Axes: easting, northing (Y,X). Orientations: east, north. UoM: m.

Definition: Well Known Text (WKT)

PROJCS["CH1903 / LV03",
    GEOGCS["CH1903",
        DATUM["CH1903",
            SPHEROID["Bessel 1841",6377397.155,299.1528128,
                AUTHORITY["EPSG","7004"]],
            TOWGS84[674.4,15.1,405.3,0,0,0,0],
            AUTHORITY["EPSG","6149"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4149"]],
    PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],
    PARAMETER["latitude_of_center",46.95240555555556],
    PARAMETER["longitude_of_center",7.439583333333333],
    PARAMETER["azimuth",90],
    PARAMETER["rectified_grid_angle",90],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",600000],
    PARAMETER["false_northing",200000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Y",EAST],
    AXIS["X",NORTH],
    AUTHORITY["EPSG","21781"]]

PROJCS["CH1903 / LV03",
    GEOGCS["CH1903",
        DATUM["CH1903",
            SPHEROID["Bessel 1841",6377397.155,299.1528128,
                AUTHORITY["EPSG","7004"]],
            TOWGS84[674.4,15.1,405.3,0,0,0,0],
            AUTHORITY["EPSG","6149"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4149"]],
    PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],
    PARAMETER["latitude_of_center",46.95240555555556],
    PARAMETER["longitude_of_center",7.439583333333333],
    PARAMETER["azimuth",90],
    PARAMETER["rectified_grid_angle",90],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",600000],
    PARAMETER["false_northing",200000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Y",EAST],
    AXIS["X",NORTH],
    AUTHORITY["EPSG","21781"]]

Definition: ESRI WKT

PROJCS["CH1903_LV03",GEOGCS["GCS_CH1903",DATUM["D_CH1903",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["Meter",1]]

Definition: PROJ.4

+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs

Definition: JavaScript (Proj4js)

proj4.defs("EPSG:21781","+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs");

Definition: OGC GML

<?xml version="1.0" encoding="UTF-8"?>
 <gml:ProjectedCRS xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="iogp-crs-21781">
  <gml:metaDataProperty>
    <epsg:CommonMetaData>
      <epsg:type>projected</epsg:type>
      <epsg:alias alias="LV03" code="882" codeSpace="urn:ogc:def:naming-system:EPSG::7302" />
      <epsg:alias alias="(CH_CH1903 / CH_PROJECTION - see alias remarks)" code="2991" codeSpace="urn:ogc:def:naming-system:EPSG::7307">
        <epsg:remarks>This EuroGeographics identifier is for a CRS similar to this but with CS axes in order north, east.</epsg:remarks>
      </epsg:alias>
      <epsg:alias alias="LV03M" code="4392" codeSpace="urn:ogc:def:naming-system:EPSG::7301" />
      <epsg:informationSource>Bundesamt fÃ¼r Landestopografie swisstopo; www.swisstopo.ch</epsg:informationSource>
      <epsg:revisionDate>2015-11-25</epsg:revisionDate>
      <epsg:changes>
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2001.290" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2005.180" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2008.022" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2015.060" />
      </epsg:changes>
      <epsg:show>true</epsg:show>
      <epsg:isDeprecated>false</epsg:isDeprecated>
    </epsg:CommonMetaData>
  </gml:metaDataProperty>
  <gml:identifier codeSpace="IOGP">urn:ogc:def:crs:EPSG::21781</gml:identifier>
  <gml:name>CH1903 / LV03</gml:name>
  <gml:remarks>Replaces LV03C (CRS code 21780) in Switzerland, but used only occasionally in Liechtenstein. Replaced by CH1903+ / LV95 (CRS code 2056).</gml:remarks>
  <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1286" />
  <gml:scope>Large and medium scale topographic mapping, cadastral and engineering survey.</gml:scope>
  <gml:conversion xlink:href="urn:ogc:def:coordinateOperation:EPSG::19922" />
  <gml:baseGeodeticCRS xlink:href="urn:ogc:def:crs:EPSG::4149" />
  <gml:cartesianCS xlink:href="urn:ogc:def:cs:EPSG::4498" />
</gml:ProjectedCRS>

<?xml version="1.0" encoding="UTF-8"?>
 <gml:ProjectedCRS xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="iogp-crs-21781">
  <gml:metaDataProperty>
    <epsg:CommonMetaData>
      <epsg:type>projected</epsg:type>
      <epsg:alias alias="LV03" code="882" codeSpace="urn:ogc:def:naming-system:EPSG::7302" />
      <epsg:alias alias="(CH_CH1903 / CH_PROJECTION - see alias remarks)" code="2991" codeSpace="urn:ogc:def:naming-system:EPSG::7307">
        <epsg:remarks>This EuroGeographics identifier is for a CRS similar to this but with CS axes in order north, east.</epsg:remarks>
      </epsg:alias>
      <epsg:alias alias="LV03M" code="4392" codeSpace="urn:ogc:def:naming-system:EPSG::7301" />
      <epsg:informationSource>Bundesamt für Landestopografie swisstopo; www.swisstopo.ch</epsg:informationSource>
      <epsg:revisionDate>2015-11-25</epsg:revisionDate>
      <epsg:changes>
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2001.290" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2005.180" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2008.022" />
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2015.060" />
      </epsg:changes>
      <epsg:show>true</epsg:show>
      <epsg:isDeprecated>false</epsg:isDeprecated>
    </epsg:CommonMetaData>
  </gml:metaDataProperty>
  <gml:identifier codeSpace="IOGP">urn:ogc:def:crs:EPSG::21781</gml:identifier>
  <gml:name>CH1903 / LV03</gml:name>
  <gml:remarks>Replaces LV03C (CRS code 21780) in Switzerland, but used only occasionally in Liechtenstein. Replaced by CH1903+ / LV95 (CRS code 2056).</gml:remarks>
  <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1286" />
  <gml:scope>Large and medium scale topographic mapping, cadastral and engineering survey.</gml:scope>
  <gml:conversion xlink:href="urn:ogc:def:coordinateOperation:EPSG::19922" />
  <gml:baseGeodeticCRS xlink:href="urn:ogc:def:crs:EPSG::4149" />
  <gml:cartesianCS xlink:href="urn:ogc:def:cs:EPSG::4498" />
</gml:ProjectedCRS>

Definition: XML

<?xml version="1.0" encoding="UTF-8"?>
 <gml:ProjectedCRS gml:id="ogrcrs314145" xmlns:gml="http://www.opengis.net/gml/3.2">
  <gml:srsName>CH1903 / LV03</gml:srsName>
  <gml:srsID>
    <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">21781</gml:name>
  </gml:srsID>
  <gml:baseCRS>
    <gml:GeographicCRS gml:id="ogrcrs314146">
      <gml:srsName>CH1903</gml:srsName>
      <gml:srsID>
        <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">4149</gml:name>
      </gml:srsID>
      <gml:usesEllipsoidalCS>
        <gml:EllipsoidalCS gml:id="ogrcrs314147">
          <gml:csName>ellipsoidal</gml:csName>
          <gml:csID>
            <gml:name gml:codeSpace="urn:ogc:def:cs:EPSG::">6402</gml:name>
          </gml:csID>
          <gml:usesAxis>
            <gml:CoordinateSystemAxis gml:id="ogrcrs314148" gml:uom="urn:ogc:def:uom:EPSG::9102">
              <gml:name>Geodetic latitude</gml:name>
              <gml:axisID>
                <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9901</gml:name>
              </gml:axisID>
              <gml:axisAbbrev>Lat</gml:axisAbbrev>
              <gml:axisDirection>north</gml:axisDirection>
            </gml:CoordinateSystemAxis>
          </gml:usesAxis>
          <gml:usesAxis>
            <gml:CoordinateSystemAxis gml:id="ogrcrs314149" gml:uom="urn:ogc:def:uom:EPSG::9102">
              <gml:name>Geodetic longitude</gml:name>
              <gml:axisID>
                <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9902</gml:name>
              </gml:axisID>
              <gml:axisAbbrev>Lon</gml:axisAbbrev>
              <gml:axisDirection>east</gml:axisDirection>
            </gml:CoordinateSystemAxis>
          </gml:usesAxis>
        </gml:EllipsoidalCS>
      </gml:usesEllipsoidalCS>
      <gml:usesGeodeticDatum>
        <gml:GeodeticDatum gml:id="ogrcrs314150">
          <gml:datumName>CH1903</gml:datumName>
          <gml:datumID>
            <gml:name gml:codeSpace="urn:ogc:def:datum:EPSG::">6149</gml:name>
          </gml:datumID>
          <gml:usesPrimeMeridian>
            <gml:PrimeMeridian gml:id="ogrcrs314151">
              <gml:meridianName>Greenwich</gml:meridianName>
              <gml:meridianID>
                <gml:name gml:codeSpace="urn:ogc:def:meridian:EPSG::">8901</gml:name>
              </gml:meridianID>
              <gml:greenwichLongitude>
                <gml:angle gml:uom="urn:ogc:def:uom:EPSG::9102">0</gml:angle>
              </gml:greenwichLongitude>
            </gml:PrimeMeridian>
          </gml:usesPrimeMeridian>
          <gml:usesEllipsoid>
            <gml:Ellipsoid gml:id="ogrcrs314152">
              <gml:ellipsoidName>Bessel 1841</gml:ellipsoidName>
              <gml:ellipsoidID>
                <gml:name gml:codeSpace="urn:ogc:def:ellipsoid:EPSG::">7004</gml:name>
              </gml:ellipsoidID>
              <gml:semiMajorAxis gml:uom="urn:ogc:def:uom:EPSG::9001">6377397.155</gml:semiMajorAxis>
              <gml:secondDefiningParameter>
                <gml:inverseFlattening gml:uom="urn:ogc:def:uom:EPSG::9201">299.1528128</gml:inverseFlattening>
              </gml:secondDefiningParameter>
            </gml:Ellipsoid>
          </gml:usesEllipsoid>
        </gml:GeodeticDatum>
      </gml:usesGeodeticDatum>
    </gml:GeographicCRS>
  </gml:baseCRS>
  <gml:definedByConversion>
    <gml:Conversion gml:id="ogrcrs314153" />
  </gml:definedByConversion>
  <gml:usesCartesianCS>
    <gml:CartesianCS gml:id="ogrcrs314154">
      <gml:csName>Cartesian</gml:csName>
      <gml:csID>
        <gml:name gml:codeSpace="urn:ogc:def:cs:EPSG::">4400</gml:name>
      </gml:csID>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs314155" gml:uom="urn:ogc:def:uom:EPSG::9001">
          <gml:name>Easting</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9906</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>E</gml:axisAbbrev>
          <gml:axisDirection>east</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs314156" gml:uom="urn:ogc:def:uom:EPSG::9001">
          <gml:name>Northing</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9907</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>N</gml:axisAbbrev>
          <gml:axisDirection>north</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
    </gml:CartesianCS>
  </gml:usesCartesianCS>
</gml:ProjectedCRS>

<?xml version="1.0" encoding="UTF-8"?>
 <gml:ProjectedCRS gml:id="ogrcrs314145" xmlns:gml="http://www.opengis.net/gml/3.2">
  <gml:srsName>CH1903 / LV03</gml:srsName>
  <gml:srsID>
    <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">21781</gml:name>
  </gml:srsID>
  <gml:baseCRS>
    <gml:GeographicCRS gml:id="ogrcrs314146">
      <gml:srsName>CH1903</gml:srsName>
      <gml:srsID>
        <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">4149</gml:name>
      </gml:srsID>
      <gml:usesEllipsoidalCS>
        <gml:EllipsoidalCS gml:id="ogrcrs314147">
          <gml:csName>ellipsoidal</gml:csName>
          <gml:csID>
            <gml:name gml:codeSpace="urn:ogc:def:cs:EPSG::">6402</gml:name>
          </gml:csID>
          <gml:usesAxis>
            <gml:CoordinateSystemAxis gml:id="ogrcrs314148" gml:uom="urn:ogc:def:uom:EPSG::9102">
              <gml:name>Geodetic latitude</gml:name>
              <gml:axisID>
                <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9901</gml:name>
              </gml:axisID>
              <gml:axisAbbrev>Lat</gml:axisAbbrev>
              <gml:axisDirection>north</gml:axisDirection>
            </gml:CoordinateSystemAxis>
          </gml:usesAxis>
          <gml:usesAxis>
            <gml:CoordinateSystemAxis gml:id="ogrcrs314149" gml:uom="urn:ogc:def:uom:EPSG::9102">
              <gml:name>Geodetic longitude</gml:name>
              <gml:axisID>
                <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9902</gml:name>
              </gml:axisID>
              <gml:axisAbbrev>Lon</gml:axisAbbrev>
              <gml:axisDirection>east</gml:axisDirection>
            </gml:CoordinateSystemAxis>
          </gml:usesAxis>
        </gml:EllipsoidalCS>
      </gml:usesEllipsoidalCS>
      <gml:usesGeodeticDatum>
        <gml:GeodeticDatum gml:id="ogrcrs314150">
          <gml:datumName>CH1903</gml:datumName>
          <gml:datumID>
            <gml:name gml:codeSpace="urn:ogc:def:datum:EPSG::">6149</gml:name>
          </gml:datumID>
          <gml:usesPrimeMeridian>
            <gml:PrimeMeridian gml:id="ogrcrs314151">
              <gml:meridianName>Greenwich</gml:meridianName>
              <gml:meridianID>
                <gml:name gml:codeSpace="urn:ogc:def:meridian:EPSG::">8901</gml:name>
              </gml:meridianID>
              <gml:greenwichLongitude>
                <gml:angle gml:uom="urn:ogc:def:uom:EPSG::9102">0</gml:angle>
              </gml:greenwichLongitude>
            </gml:PrimeMeridian>
          </gml:usesPrimeMeridian>
          <gml:usesEllipsoid>
            <gml:Ellipsoid gml:id="ogrcrs314152">
              <gml:ellipsoidName>Bessel 1841</gml:ellipsoidName>
              <gml:ellipsoidID>
                <gml:name gml:codeSpace="urn:ogc:def:ellipsoid:EPSG::">7004</gml:name>
              </gml:ellipsoidID>
              <gml:semiMajorAxis gml:uom="urn:ogc:def:uom:EPSG::9001">6377397.155</gml:semiMajorAxis>
              <gml:secondDefiningParameter>
                <gml:inverseFlattening gml:uom="urn:ogc:def:uom:EPSG::9201">299.1528128</gml:inverseFlattening>
              </gml:secondDefiningParameter>
            </gml:Ellipsoid>
          </gml:usesEllipsoid>
        </gml:GeodeticDatum>
      </gml:usesGeodeticDatum>
    </gml:GeographicCRS>
  </gml:baseCRS>
  <gml:definedByConversion>
    <gml:Conversion gml:id="ogrcrs314153" />
  </gml:definedByConversion>
  <gml:usesCartesianCS>
    <gml:CartesianCS gml:id="ogrcrs314154">
      <gml:csName>Cartesian</gml:csName>
      <gml:csID>
        <gml:name gml:codeSpace="urn:ogc:def:cs:EPSG::">4400</gml:name>
      </gml:csID>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs314155" gml:uom="urn:ogc:def:uom:EPSG::9001">
          <gml:name>Easting</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9906</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>E</gml:axisAbbrev>
          <gml:axisDirection>east</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
      <gml:usesAxis>
        <gml:CoordinateSystemAxis gml:id="ogrcrs314156" gml:uom="urn:ogc:def:uom:EPSG::9001">
          <gml:name>Northing</gml:name>
          <gml:axisID>
            <gml:name gml:codeSpace="urn:ogc:def:axis:EPSG::">9907</gml:name>
          </gml:axisID>
          <gml:axisAbbrev>N</gml:axisAbbrev>
          <gml:axisDirection>north</gml:axisDirection>
        </gml:CoordinateSystemAxis>
      </gml:usesAxis>
    </gml:CartesianCS>
  </gml:usesCartesianCS>
</gml:ProjectedCRS>

Definition: GeoServer

21781=PROJCS["CH1903 / LV03",GEOGCS["CH1903",DATUM["CH1903",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[674.4,15.1,405.3,0,0,0,0],AUTHORITY["EPSG","6149"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4149"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["rectified_grid_angle",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Y",EAST],AXIS["X",NORTH],AUTHORITY["EPSG","21781"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=somerc"
	"lat_0=46.95240555555556"
	"lon_0=7.439583333333333"
	"k_0=1"
	"x_0=600000"
	"y_0=200000"
	"ellps=bessel"
	"towgs84=674.4,15.1,405.3,0,0,0,0"
	"units=m"
	"no_defs"
END

Definition: MapServer - Python

wkt = '''PROJCS["CH1903 / LV03",GEOGCS["CH1903",DATUM["CH1903",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[674.4,15.1,405.3,0,0,0,0],AUTHORITY["EPSG","6149"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4149"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["rectified_grid_angle",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Y",EAST],AXIS["X",NORTH],AUTHORITY["EPSG","21781"]]'''
m = mapObj('')
m.setWKTProjection(ref.ExportToWkt())
lyr = layerObj(m)
lyr.setWKTProjection(ref.ExportToWkt())

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs">
	<Layer srs="+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs">
	</Layer>
</Map>

Definition: Mapnik - Python

proj4 = '+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 21781, 'EPSG', 21781, '+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs ', 'PROJCS["CH1903 / LV03",GEOGCS["CH1903",DATUM["CH1903",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[674.4,15.1,405.3,0,0,0,0],AUTHORITY["EPSG","6149"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4149"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["rectified_grid_angle",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Y",EAST],AXIS["X",NORTH],AUTHORITY["EPSG","21781"]]');

Definition: OGC WKT

PROJCS["CH1903 / LV03",GEOGCS["CH1903",DATUM["CH1903",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[674.4,15.1,405.3,0,0,0,0],AUTHORITY["EPSG","6149"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4149"]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["rectified_grid_angle",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",600000],PARAMETER["false_northing",200000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Y",EAST],AXIS["X",NORTH],AUTHORITY["EPSG","21781"]]

Coordinates with same geodetic base (CH1903):

EPSG:21782 CH1903 / LV03C-G (map)