National Transfer Format Files (NTF)
NTF files are mostly used by the U.K. Ordnance Survey (OS). For more on the Ordnance Survey, see their web site at http://www.ordnancesurvey.co.uk.
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 CONNECTION must
also include a layer number (as per the layer number from
ogrinfo, but minus
one).
Here’s an example that uses ogrinfo on an NTF file to retrieve layer
numbers:
> 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)For the LANDLINE_LINE
layer, the ogrinfo layer number
is 2; however, when referring to
this layer in a map file connection, the layer number is 1.
Here’s an example that uses ogrinfo to examine the structure of an NTF
layer:
> ogrinfo llcontours.ntf LANDLINE_LINE
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)
...