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15. National Transfer Format Files (NTF)

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NTF files are mostly used by the United Kingdom Ordnance Survey (OS). For more on the Ordnance Survey, see their website at: http://www.ordnancesurvey.co.uk

File listing

NTF files have an NTF extension.

Data Access / Connection Method

  • NTF access requires OGR.
  • The path to the NTF file is required in the CONNECTION string. It may be relative to the SHAPEPATH setting in the map file or the full path.
  • The DATA parameter is used to specify the layer to use

OGRINFO Examples

Using ogrinfo on an NTF file to retrieve layer names:

> ogrinfo llcontours.ntf
ERROR 4: NTF Driver doesn't support update.
Had to open data source read-only.
INFO: Open of `llcontours.ntf'
using driver `UK .NTF' successful.
1: LANDLINE_POINT (Point)
2: LANDLINE_LINE (Line String)
3: LANDLINE_NAME (Point)
4: FEATURE_CLASSES (None)

Using ogrinfo to examine the structure of an NTF layer:

> ogrinfo llcontours.ntf LANDLINE_LINE -summary
ERROR 4: NTF Driver doesn't support update.
Had to open data source read-only.
INFO: Open of `llcontours.ntf'
using driver `UK .NTF' successful.

Layer name: LANDLINE_LINE
Geometry: Line String
Feature Count: 491
Extent: (279000.000000, 187000.000000) - (280000.000000, 188000.000000)
Layer SRS WKT:
PROJCS["OSGB 1936 / British National Grid",
        GEOGCS["OSGB 1936",
                DATUM["OSGB_1936",
                        SPHEROID["Airy 1830",6377563.396,299.3249646,
                                AUTHORITY["EPSG","7001"]],
                                AUTHORITY["EPSG","6277"]],
                PRIMEM["Greenwich",0,
                                AUTHORITY["EPSG","8901"]],
                UNIT["degree",0.0174532925199433],
                AUTHORITY["EPSG","4277"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",49],
PARAMETER["central_meridian",-2],
PARAMETER["scale_factor",0.999601272],
PARAMETER["false_easting",400000],
PARAMETER["false_northing",-100000],
UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
        AUTHORITY["EPSG","27700"]]
LINE_ID: Integer (6.0)
FEAT_CODE: String (4.0)
...

Map File Example:

LAYER
  NAME ntf_uk
  TYPE LINE
  CONNECTIONTYPE OGR
  CONNECTION "./ntf/llcontours.ntf"
  DATA "LANDLINE_LINE"
  STATUS DEFAULT
  CLASS
    NAME "Contours"
    STYLE
     COLOR 0 150 200
    END
  END
END
by Jeff McKenna last modified 2008-09-09 11:40
Contributors: Tyler Mitchell, Jeff McKenna

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