Reprojecting shapefiles with ogr2ogr

Firstly, you might want to view the projection information in the shapefile, ROAD_CENTRELINES.shp in this case.  The perl one-liner stops ogrinfo from printing copious data about each vector feature in the shapefile:

fmark@fmark-laptop:~$ ogrinfo -ro -al ROAD_CENTERLINES.shp | perl -e 'while (<STDIN>) { if (/OGRFeature/) { exit } print; }'
INFO: Open of `ROAD_CENTERLINES.shp'
using driver `ESRI Shapefile' successful.

Layer name: ROAD_CENTERLINES
Geometry: Line String
Feature Count: 4596
Extent: (128.999678, -25.998883) - (138.000000, -11.067068)
Layer SRS WKT:
GEOGCS["Longitude / Latitude (GDA 94)",
DATUM["Unknown",
SPHEROID["GRS_80",6378137,298.2572221010595]],
PRIMEM["Greenwich",0],
UNIT["Degree",0.017453292519943295]]
ROAD_NAME: String (100.0)
ROAD_TYPE: String (15.0)
ROAD_SUFFI: String (15.0)
ROAD_LABEL: String (130.0)
Length: Real (19.11)

We can see from this that the geographic coordinate system of the shapefile is GDA94.

In order to specify the projection we want to use, we need to know its EPSG code.  What’s an EPSG code?  Its a number that uniquely defines some well-known projections (according to Wikipedia, EPSG stands for the European Petroleum Survey Group, so we have big oil to thank for our daily GIS tools, as well as big military). Some useful Australian EPSG codes are:

4326 WGS84
4283 GDA94
4202 AGD66
3577 GDA94 / Australian Albers
3112 GDA94 / Geoscience Australia Lambert
28348 GDA94 / MGA zone 48
28349 GDA94 / MGA zone 49
28350 GDA94 / MGA zone 50
28351 GDA94 / MGA zone 51
28352 GDA94 / MGA zone 52
28353 GDA94 / MGA zone 53
28354 GDA94 / MGA zone 54
28355 GDA94 / MGA zone 55
28356 GDA94 / MGA zone 56
28357 GDA94 / MGA zone 57
28358 GDA94 / MGA zone 58

More can be found at http://spatialreference.org/.

In this case, I want MGA zone 53, or EPSG:28353.  So to reproject:

ogr2ogr -t_srs 'EPSG:28353' ROAD_CENTERLINES_MGAZ53.shp ROAD_CENTERLINES.shp

Note that the output filename comes before the input filename.  Also, for some reason on ubuntu karmic there was a missing dependency, so I needed to:

sudo apt-get install libproj-dev

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  1. 1 Reprojecting from AGD66 to GDA94 « Opaque Overlay

    […] 3, 2010 in Uncategorized In a previous installment I demonstrated how to use ogr2ogr to reproject shapefiles. It turns out that its a bit trickier when you are reprojecting from AGD66 to GDA94 (and vice […]




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