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Raster Coordinate Reference
The coordinate reference is typically defined when the raster column is added to the business table. For normal operations from ArcGIS applications such as ArcCatalog, this would occur when a raster catalog or a raster dataset is created.

It is possible to create a raster that does not have a coordinate reference system defined. Although these types of rasters can be used to represent picture elements within application, but cannot be include in a mosaic operation with other raster data, because without a coordinate reference system, they cannot be georeferenced.

If the coordinate reference system for a raster is not known a load time, it is possible to set it to UNKNOWN, load the raster data into the raster, and update the coordinate reference system to a known system after the loading process has commenced. A raster with an UNKNOWN coordinate reference system is considered to be georeferenced and can participate in a mosaic operation.

The coordinate reference system is set using the CAPI SE_rascolinfo_set_coordref and the JAVA API setCoordRef method on the SeRasterColumn object.

LONG          rc;

      SE_RASCOLINFO rascol_info;

      SE_COORDREF   coordref;

      PE_COORDSYS   pe = NULL;

/* Initialize the SE_RASCOLINFO structure */
rc = SE_rascolinfo_create (&rascol_info);
      check_error (rc, NULL, NULL, "SE_rascolinfo_create");

/* Initialize the coordinate reference structure */

  rc =
        SE_coordref_create (&coordref);
        check_error (rc, NULL, NULL, "SE_coordref_create");

 /* Generate the coordinate reference string */
pe = pe_factory (PE_PCS_WGS_1984_UTM_31N);
check_error (NULL == pe, NULL, NULL, "pe_factory");

      /* Set the coordinate reference string on the coordinate */
      /* coordinate reference structure                        */  
      rc = SE_coordref_set_coordsys (coordref, pe);

      check_error (rc, NULL, NULL, "SE_coordref_set_coordsys");

 

      /* Set the coordinate reference on the raster column info */

      /* structure                                              */
      rc = SE_rascolinfo_set_coordref (rascol_info, coordref);

      check_error (rc, NULL, NULL, "SE_rascolinfo_set_coordref");

 

      /* Clean up the structures */
     pe_coordsys_del (pe);

    SE_coordref_free (coordref);

      /* Add the raster column to the business table. */
     printf ("Creating raster column.../n\n");
     rc =
     SE_rastercolumn_create (connection, rascol_info);
     check_error (rc, connection, NULL, "SE_rastercolumn_create");

 
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