Oracle Geometries

See http://docs.oracle.com/cd/B28359_01/appdev.111/b28400/sdo_objrelschema.htm for more information.

The Oracle sdo_geometry is made up of multiple parts:

• GType: 2003 for areas, 2002 for lines, 2001 for points. Other values are possible, but are rarely seen in HPD. Some HPD functions will return sounding clusters as a 3D set of point locations, gtype 3005.

• SRID: In HPD, the SRID should always be the value p_schema_constants.default_source_geom_srid.

• SDO_POINT: In HPD, the SDO_POINT parameter is always NULL.

• Element information: Each triplet of values has the following meaning:

• 1st value denotes the position of the start coordinate of a ring in the ordinate array. This is always one for the first triplet.

• 2nd value denotes the type of the triplet. Possible values are 1003 (outer ring), 2003 (inner ring), 2 (line), 1 (point)

• 3rd value denotes how the vertices in the polygon are connected.

• 1 = vertices are connected as straight lines using point-to-point line. This is the typical value used.

• 3 = vertices define a 2 point rectangle.

• Ordinates Contains coordinates of vertices that make up a ring. Except for some PCE functions, all geometries are in LLDG in the database datum which by default is WGS84. These are X,Y pairs so the longitude comes before latitude.

Constraint: Outer rings must be listed before inner rings (islands/holes). Outer rings are always counter-clockwise, while inner rings are always clockwise.

Point geometries:

• Gtype is 2001

• Element information is 1,1,1

• Ordinates are the single X,Y pair

Example

Line geometries:

• Gtype is 2002

• Element information is 1,2,1

• Ordinates are multiple X,Y pairs

Example

Area geometries with no inner rings:

• Gtype is 2003

• Element information is 1,1003,1 or 1,1003,3

• Ordinates are multiple X,Y pairs. The last pair must be the same as the first pair, to close the area.

Example

Area geometries with inner rings:

• Gtype is 2003

• Element information is 1,1003,1 for the outer ring, and then X,2003,1 for the inner rings where X is the index into the ordinate array.

• Ordinates are multiple X,Y pairs. Each ring's set of ordinates must be the same as the ring's first set of ordinates, to close the ring.

Example