Name
National Transfer Format Files (NTF)
Synopsis
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.
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
CONNECTIONstring. It may be relative to theSHAPEPATHsetting in the map file or the full path.The
CONNECTIONmust also include a layer number (as per the layer number fromogrinfo, but minus one).
ogrinfo examples
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 ...