Shapefile GDAL – How to Generate UTM Grid (Graticule)

gdalgrids-graticulesshapefileutm

I'm looking for a shapefile containing an 1000m or 2000m UTM grid ("graticule"). All I was about to find on the web is a 10000m UTM grid (here: http://en.giswiki.net/wiki/UTM) and I am aware that a 1000m UTM grid for the whole world might be quite big.

That's why I'm now wondering if and how it would be possible to generate such a shapefile for a part of the world. I would prefer to use open source tools like gdal. Others output formats than a shapefile might be ok too.

Has anyone an idea?

Best Answer

Thanks to the other answers I was able to do it this way:

Determine the wanted UTM coordinates.
- UTM zone: determine the zone between 1 and 60 by looking at a map like here http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system
- EPSG code for the UTM zone: on WGS84 it is EPSG:326xx, where xx is the number of the zone (see http://www.spatialreference.org/ref/?page=18&search=UTM+zone). In Europe some maps use ETRS89 instead of WGS84. There is also a corresponding EPSG code (EPSG:258xx) but the difference to WGS84 is too small to notice, so that you can as well use WGS84.
- Easting: within a zone the easting coordinate is always greater than 100000m and smaller than 900000m, so I simply take 100000-900000 as limits for the easting value.
- Northing: it's the distance to the equator, let's say I need a 1000km part between 5000000m and 6000000m.
Use SAGA GIS as suggested by johanvdw. Start a new project, select MODULES-SHAPES/TOOLS > CREATE GRATICULE, enter the following values and click “Okay”:

(It might alternatively be possible to use QGIS as suggested by Darren Cope)
Go to the tab “Data”, right click on the graticule in the tree and choose “Save as” to create a shapefile. Let's say “UTM_without_CS.shp”.
Use ogr2ogr to attribute a coordinate system. Let's say you want UTM zone 30 on WGS 84 (= EPSG:32630):

ogr2ogr -a_srs EPSG:32630 UTM.shp UTM_without_CS.shp

That's it!

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[GIS] Generating Grid Maps from shapefiles

I suspect that your challenge is not with generating the grid but rather deciding how to assign the pre-existing geographies to particular hexagons in the grid (assuming n.polygons == n.hexagons). One approach might be to use the Hungarian Algorithm. Given the distances from the centroid of every pre-existing geography to the centroid of every hexagon in your grid (or some other distance) the Hungarian algorithm could calculate the solution that minimises the sum of displacements from the original locations to the new locations. For more information have a look at an early stage R package which does this here.

Of course, this approach does not guarantee that polygons will maintain the same neighbours but might go some way to helping. I am still trying to solve a graphical approach to this and have a question out here which addresses this.

Python – Auto-select UTM Zone Based on Grid Intersection

There's the utm package, a bidirectional UTM-WGS84 converter for python. It's able to convert a (latitude, longitude) tuple into an UTM coordinate:

import utm
utm.from_latlon(51.2, 7.5)
>>> (395201.3103811303, 5673135.241182375, 32, 'U')

Best Answer

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Python – Auto-select UTM Zone Based on Grid Intersection

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