.. _sdts:

*****************************************************************************
 SDTS
*****************************************************************************

This is a United States Geological Survey (USGS) format. SDTS has a raster and a vector format.  The raster format is not supported in MapServer.  Only the vector formats are supported, including VTP and DLG files.

File listing
------------------
*  SDTS files are often organized into state-sized pieces.  For 
   example, all of the state of Maryland (MD), U.S.A.
*  Files are also available for multiple types of features 
   including hydrography, transportation and administrative boundaries.

This example uses transportation data, which consists of 35 separate files, each with the suffix DDF:

::

	MDTRAHDR.DDF  MDTRARRF.DDF  MDTRCATS.DDF
	MDTRDQCG.DDF  MDTRFF01.DDF  MDTRLE02.DDF
	MDTRNA03.DDF  MDTRNO03.DDF  MDTRSPDM.DDF
	MDTRAMTF.DDF  MDTRBFPS.DDF  MDTRCATX.DDF
	MDTRDQHL.DDF  MDTRIDEN.DDF  MDTRLE03.DDF
	MDTRNE03.DDF  MDTRPC01.DDF  MDTRSTAT.DDF
	MDTRARDF.DDF  MDTRBMTA.DDF  MDTRDDSH.DDF
	MDTRDQLC.DDF  MDTRIREF.DDF  MDTRNA01.DDF
	MDTRNO01.DDF  MDTRPC02.DDF  MDTRXREF.DDF
	MDTRARDM.DDF  MDTRCATD.DDF  MDTRDQAA.DDF
	MDTRDQPA.DDF  MDTRLE01.DDF  MDTRNA02.DDF
	MDTRNO02.DDF  MDTRPC03.DDF

Data Access / Connection Method
--------------------------------

*  SDTS access is available in MapServer through OGR.
*  The CONNECTIONTYPE OGR parameter must be used.
*  The path (which can be relative) to the catalog file (????CATD.DDF) is required, 
   including file extension.
*  There are multiple layers in the SDTS catalog, some 
   of which are only attributes and have no geometries.
*  The layer name is specified with the DATA parameter

OGRINFO Examples
-------------------

Using ogrinfo on a catalog file (note that the first 7 layers do not have geometries):

::

	> ogrinfo /data/sdts/MD/MDTRCATD.DDF
	Had to open data source read-only.
	INFO: Open of `MDTRCATD.DDF'
	using driver `SDTS' successful.
	1: ARDF (None)
	2: ARRF (None)
	3: AMTF (None)
	4: ARDM (None)
	5: BFPS (None)
	6: BMTA (None)
	7: AHDR (None)
	8: NE03 (Point)
	9: NA01 (Point)
	10: NA02 (Point)
	11: NA03 (Point)
	12: NO01 (Point)
	13: NO02 (Point)
	14: NO03 (Point)
	15: LE01 (Line String)
	16: LE02 (Line String)
	17: LE03 (Line String)
	18: PC01 (Polygon)
	19: PC02 (Polygon)
	20: PC03 (Polygon)

Using ogrinfo to examine the structure of the file/layer:

::

	> ogrinfo /data/sdts/MD/MDTRCATD.DDF LE01 -summary
	Had to open data source read-only.
	INFO: Open of `MDTRCATD.DDF'
	using driver `SDTS' successful.

	Layer name: LE01
	Geometry: Line String
	Feature Count: 780
	Extent: (-80.000289, 36.999774) - (-74.999711, 40.000225)
	Layer SRS WKT:
	GEOGCS["NAD27",
    DATUM["North_American_Datum_1927",
        SPHEROID["Clarke 1866",6378206.4,294.978698213901]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433]]
	RCID: Integer (0.0)
	SNID: Integer (0.0)
	ENID: Integer (0.0)
	ENTITY_LABEL: String (7.0)
	ARBITRARY_EXT: String (1.0)
	RELATION_TO_GROUND: String (1.0)
	VERTICAL_RELATION: String (1.0)
	OPERATIONAL_STATUS: String (1.0)
	ACCESS_RESTRICTION: String (1.0)
	OLD_RAILROAD_GRADE: String (1.0)
	WITH_RAILROAD: String (1.0)
	COVERED: String (1.0)
	HISTORICAL: String (1.0)
	LIMITED_ACCESS: String (1.0)
	PHOTOREVISED: String (1.0)
	LANES: Integer (2.0)
	ROAD_WIDTH: Integer (3.0)
	BEST_ESTIMATE: String (1.0)
	ROUTE_NUMBER: String (7.0)
	ROUTE_TYPE: String (9.0)

Map File Example:

::

	LAYER
	  NAME sdts_maryland
	  TYPE LINE
	  CONNECTIONTYPE OGR
	  CONNECTION "data/sdts/MD/MDTRCATD.DDF"
          DATA "LE01"
	  STATUS DEFAULT
	  CLASS
            STYLE
              COLOR 0 0 0
            END
	  END
	END