EPSG:4041

GEOGCS["Unknown datum based upon the Average Terrestrial System 1977 ellipsoid",DATUM["D_Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["Average_Terrestrial_System_1977",6378135,298.257]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]

+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs 

proj4.defs("EPSG:4041","+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs");

<?xml version="1.0" encoding="UTF-8"?>
 <gml:GeodeticCRS 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="epsg-crs-4041">
   <gml:metaDataProperty>
      <epsg:CommonMetaData>
         <epsg:type>geographic 2D</epsg:type>
         <epsg:informationSource>OGP</epsg:informationSource>
         <epsg:revisionDate>2004-01-06</epsg:revisionDate>
         <epsg:changes>
            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2000.420" />
            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2003.370" />
         </epsg:changes>
         <epsg:show>false</epsg:show>
         <epsg:isDeprecated>false</epsg:isDeprecated>
      </epsg:CommonMetaData>
   </gml:metaDataProperty>
   <gml:identifier codeSpace="OGP">urn:ogc:def:crs:EPSG::4041</gml:identifier>
   <gml:name>Unknown datum based upon the Average Terrestrial System 1977 ellipsoid</gml:name>
   <gml:remarks>Use only in cases where geodetic datum is unknown.</gml:remarks>
   <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1263" />
   <gml:scope>Not recommended.</gml:scope>
   <gml:ellipsoidalCS xlink:href="urn:ogc:def:cs:EPSG::6422" />
   <gml:geodeticDatum xlink:href="urn:ogc:def:datum:EPSG::6041" />
</gml:GeodeticCRS>

<?xml version="1.0" encoding="UTF-8"?>
 <gml:GeographicCRS gml:id="ogrcrs439524" xmlns:gml="http://www.opengis.net/gml/3.2">
  <gml:srsName>Unknown datum based upon the Average Terrestrial System 1977 ellipsoid</gml:srsName>
  <gml:srsID>
    <gml:name gml:codeSpace="urn:ogc:def:crs:EPSG::">4041</gml:name>
  </gml:srsID>
  <gml:usesEllipsoidalCS>
    <gml:EllipsoidalCS gml:id="ogrcrs439525">
      <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="ogrcrs439526" 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="ogrcrs439527" 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="ogrcrs439528">
      <gml:datumName>Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid</gml:datumName>
      <gml:datumID>
        <gml:name gml:codeSpace="urn:ogc:def:datum:EPSG::">6041</gml:name>
      </gml:datumID>
      <gml:usesPrimeMeridian>
        <gml:PrimeMeridian gml:id="ogrcrs439529">
          <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="ogrcrs439530">
          <gml:ellipsoidName>Average Terrestrial System 1977</gml:ellipsoidName>
          <gml:ellipsoidID>
            <gml:name gml:codeSpace="urn:ogc:def:ellipsoid:EPSG::">7041</gml:name>
          </gml:ellipsoidID>
          <gml:semiMajorAxis gml:uom="urn:ogc:def:uom:EPSG::9001">6378135</gml:semiMajorAxis>
          <gml:secondDefiningParameter>
            <gml:inverseFlattening gml:uom="urn:ogc:def:uom:EPSG::9201">298.257</gml:inverseFlattening>
          </gml:secondDefiningParameter>
        </gml:Ellipsoid>
      </gml:usesEllipsoid>
    </gml:GeodeticDatum>
  </gml:usesGeodeticDatum>
</gml:GeographicCRS>

4041=GEOGCS["Unknown datum based upon the Average Terrestrial System 1977 ellipsoid",DATUM["Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["Average Terrestrial System 1977",6378135,298.257,AUTHORITY["EPSG","7041"]],AUTHORITY["EPSG","6041"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4041"]]

PROJECTION
	"proj=longlat"
	"a=6378135"
	"b=6356750.304921594"
	"no_defs"
END

wkt = '''GEOGCS["Unknown datum based upon the Average Terrestrial System 1977 ellipsoid",DATUM["Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["Average Terrestrial System 1977",6378135,298.257,AUTHORITY["EPSG","7041"]],AUTHORITY["EPSG","6041"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4041"]]'''
m = mapObj('')
m.setWKTProjection(ref.ExportToWkt())
lyr = layerObj(m)
lyr.setWKTProjection(ref.ExportToWkt())

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs">
	<Layer srs="+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs">
	</Layer>
</Map>

proj4 = '+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs'
m = Map(256,256,proj4)
lyr = Layer('Name',proj4)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 4041, 'EPSG', 4041, '+proj=longlat +a=6378135 +b=6356750.304921594 +no_defs ', 'GEOGCS["Unknown datum based upon the Average Terrestrial System 1977 ellipsoid",DATUM["Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["Average Terrestrial System 1977",6378135,298.257,AUTHORITY["EPSG","7041"]],AUTHORITY["EPSG","6041"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4041"]]');

GEOGCS["Unknown datum based upon the Average Terrestrial System 1977 ellipsoid",DATUM["Not_specified_based_on_Average_Terrestrial_System_1977_ellipsoid",SPHEROID["Average Terrestrial System 1977",6378135,298.257,AUTHORITY["EPSG","7041"]],AUTHORITY["EPSG","6041"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4041"]]

[0, 0, (6378135.0, 6356750.304921594, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0), -1]