File listing

TIGER/Line Files

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TIGER/Line files are created by the U.S. Census Bureau and cover the entire United States. They are often referred to simply as TIGER files. For more information, see http://www.census.gov/geo/www/tiger/.

TIGER/Line files are text files and directory-based data sources. For example, one county folder TGR06059 contains several associated files:

     TGR06059.RT1 TGR06059.RT2 TGR06059.RT4 TGR06059.RT5     TGR06059.RT6 TGR06059.RT7 TGR06059.RT8 TGR06059.RTA     TGR06059.RTC TGR06059.RTH TGR06059.RTI TGR06059.RTP     TGR06059.RTR TGR06059.RTS TGR06059.RTT TGR06059.RTZ 

Data access/connection method

• TIGER/Line access occurs through OGR.

• The full path to the directory containing the associated files is required in the CONNECTION string. The layer number is added to the CONNECTION string, after the path, separated by a comma: for example., CONNECTION "/tiger/data,0".

• The layer number in the map file is actually the ogrinfo layer number, minus one.

ogrinfo examples

Here's an example that uses ogrinfo on a TIGER directory to retrieve layer numbers:

     > ogrinfo TGR06059 (NOTE that this is a directory)     ERROR 4: Tiger Driver doesn't support update.     Had to open data source read-only.     INFO: Open of 'TGR06059'     using driver 'TIGER' successful.     1: CompleteChain (Line String)     2: AltName (None)     3: FeatureIds (None)     4: ZipCodes (None)     5: Landmarks (Point)     6: AreaLandmarks (None)     7: Polygon (None)     8: PolygonCorrections (None)     9: EntityNames (Point)     10: PolygonEconomic (None)     11: IDHistory (None)     12: PolyChainLink (None)     13: PIP (Point)     14: TLIDRange (None)     15: ZeroCellID (None)     16: OverUnder (None)     17: ZipPlus4 (None) 

For the CompleteChain Line layer, the ogrinfo layer number is 1. However, when referring to this layer in a map file CONNECTION, the layer number will be one less, 0.

Here's an example that uses ogrinfo to examine the structure of the TIGER layer CompleteChain:

     > ogrinfo TGR06059 CompleteChain     ERROR 4: Tiger Driver doesn't support update.     Had to open data source read-only.     INFO: Open of 'TGR06059'     using driver 'TIGER' successful.           Layer name: CompleteChain     Geometry: Line String     Feature Count: 123700     Extent: (-118.125898, 33.333992) - (-117.412987, 33.947512)     Layer SRS WKT:     GEOGCS["NAD83",         DATUM["North_American_Datum_1983",             SPHEROID["GRS 1980",6378137,298.257222101]],         PRIMEM["Greenwich",0],         UNIT["degree",0.0174532925199433]]     MODULE: String (8.0)     TLID: Integer (10.0)     SIDE1: Integer (1.0)     SOURCE: String (1.0)     FEDIRP: String (2.0)     FENAME: String (30.0)     FETYPE: String (4.0)     FEDIRS: String (2.0)     CFCC: String (3.0)     FRADDL: String (11.0)     TOADDL: String (11.0)     FRADDR: String (11.0)     TOADDR: String (11.0)     FRIADDL: String (1.0)     TOIADDL: String (1.0)     FRIADDR: String (1.0)     TOIADDR: String (1.0)     ZIPL: Integer (5.0) 

Map file example

     LAYER       NAME Complete_Chain       TYPE LINE       STATUS DEFAULT       CONNECTIONTYPE OGR       CONNECTION "/path/to/data/tiger/TGR06059,0"       CLASS         COLOR 153 102 0       END     END # Layer