PDX-OSGeo 2013 Unconference

Registration

Register for the 2013 PDX-OSGeo unconference

Notes

Review Oregon Walks GIS Jam Inventory

• review url

Data Munging with GDAL/OGR

• GDAL and OGR can be used for all kinds of raster and vector data manipulation. It is the underlying engine for many softwares. The command line and various language bindings are handy for scripts or inclusion in other software.
• Get information about USGS geopdf topo file:

gdalinfo OR_Portland_282793_1897_62500_geo.pdf

• Convert geopdf to geotif:

gdal_translate OR_Portland_282793_1897_62500_geo.pdf topo.tif

• Reproject Natural Earth data from WGS84 to Spereical Mercator:

gdalwarp -s_srs EPSG:4326 -t_srs EPSG:3857 -r bilinear -te -20037508.34 -20037508.34 20037508.34 20037508.34 NE2_HR_LC_SR_W.tif natural-earth-2-mercator.tif --config GDAL_CACHEMAX 500

• Get info about that file (to confirm the change):

gdalinfo natural-earth-2-mercator.tif

• Add overviews to file:

gdaladdo -r average natural-earth-2-mercator.tif 2 4 8 16 32 64 128 256 1024 --config GDAL_CACHEMAX 400

• Get info about that file (note the overviews):

gdalinfo natural-earth-2-mercator.tif

• Record these commands (if using Windows/dos):

doskey /history > gdal_commands.txt

QGIS tips

• Rename fields in shapefile with Table Manager plugin
• save as in a new format or projection (or properly assign projection)
• Prj2EPSG was shown as a way to get projection hints
• Other tips too

Notes for next year

• Remember to email previous year attendees
• Determine best day (in relation to GIS In Action and weekday/weekend)