Comments on: Thursday Tip Day: Converting free contour data for use in GIS http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/ Travels in a digital world Wed, 08 Feb 2012 13:03:07 +0000 hourly 1 http://wordpress.org/?v= By: Microsoft Technical Support http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/comment-page-1/#comment-118159 Microsoft Technical Support Sat, 16 Oct 2010 07:35:00 +0000 http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/#comment-118159 The freeware GIS MicroDEM can also convert DEMs to contour shapefiles. The freeware GIS MicroDEM can also convert DEMs to contour shapefiles.

]]> By: admin http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/comment-page-1/#comment-19160 admin Fri, 07 Mar 2008 09:24:31 +0000 http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/#comment-19160 Hi Leszek, Many thanks for these alternative options- really handy to know about, particularly as we can't rely on the SMC always making the data available. I will edit the post to direct people to these alternatives. Thanks for popping by! Jo Hi Leszek,

Many thanks for these alternative options- really handy to know about, particularly as we can’t rely on the SMC always making the data available. I will edit the post to direct people to these alternatives.

Thanks for popping by!

Jo

]]> By: Leszek Pawlowicz http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/comment-page-1/#comment-19114 Leszek Pawlowicz Thu, 06 Mar 2008 18:45:25 +0000 http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/#comment-19114 The freeware GIS SAGA can also create contour shapefiles from a DEM in ESRI ArcGrid format (and a number of different grid formats, but not GeoTiff). http://www.saga-gis.uni-goettingen.de/html/index.php The freeware GIS SAGA can also create contour shapefiles from a DEM in ESRI ArcGrid format (and a number of different grid formats, but not GeoTiff).

http://www.saga-gis.uni-goettingen.de/html/index.php

]]> By: Leszek Pawlowicz http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/comment-page-1/#comment-19113 Leszek Pawlowicz Thu, 06 Mar 2008 18:31:26 +0000 http://www.archaeogeek.com/blog/2008/03/06/thursday-tip-day-converting-free-contour-data-for-use-in-gis/#comment-19113 The program dem2topo (mentioned in your link) will convert SRTM-90m 3-arc-second DEM files (GeoTiff format) from the USGS Seamless Server (seamless.usgs.gov) directly to shapefiles, and let you set both the contour intervals and the units: http://freegeographytools.com/2007/converting-digital-elevation-models-to-shapefiledxf-contours While the USGS SRTM-90 data is "finished", i.e. voids and anomalies supposedly fixed, it still has issues. Looks like the Scots spent a lot of time cleaning up the data. An alternative source of "finished" SRTM-90 data is CGIAR: http://freegeographytools.com/2007/new-fixed-versions-of-srtm-90-data-available Visually, this data looks a lot cleaner than the USGS SRTM data, and works with dem2topo if you download the DEMs in GeoTiff format. The freeware GIS MicroDEM can also convert DEMs to contour shapefiles. It supports more DEM formats than dem2topo, but the shapefile output isn't as good: http://freegeographytools.com/2007/microdem-a-swiss-army-knife-of-terrain-and-gis-tools The program dem2topo (mentioned in your link) will convert SRTM-90m 3-arc-second DEM files (GeoTiff format) from the USGS Seamless Server (seamless.usgs.gov) directly to shapefiles, and let you set both the contour intervals and the units:

http://freegeographytools.com/2007/converting-digital-elevation-models-to-shapefiledxf-contours

While the USGS SRTM-90 data is “finished”, i.e. voids and anomalies supposedly fixed, it still has issues. Looks like the Scots spent a lot of time cleaning up the data.

An alternative source of “finished” SRTM-90 data is CGIAR:

http://freegeographytools.com/2007/new-fixed-versions-of-srtm-90-data-available

Visually, this data looks a lot cleaner than the USGS SRTM data, and works with dem2topo if you download the DEMs in GeoTiff format.

The freeware GIS MicroDEM can also convert DEMs to contour shapefiles. It supports more DEM formats than dem2topo, but the shapefile output isn’t as good:

http://freegeographytools.com/2007/microdem-a-swiss-army-knife-of-terrain-and-gis-tools

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