[GRASS-dev] Re: sample dataset update

Markus Metz markus.metz.giswork at googlemail.com
Fri Jun 24 06:23:39 EDT 2011

On Fri, Jun 24, 2011 at 11:13 AM, Markus Metz
<markus.metz.giswork at googlemail.com> wrote:
> On Thu, Jun 23, 2011 at 6:44 AM, Helena Mitasova <hmitaso at ncsu.edu> wrote:
>> Below are some plans for data updates. It would be useful to put this on wiki
>> so that others can comment, add, modify. I was thinking about
>> http://grass.osgeo.org/wiki/Sample_datasets
>> but this is really for downloads, so perhaps as a new section here?
>> http://grass.osgeo.org/wiki/GRASS_7_ideas_collection
> I would suggest to keep GRASS 7 ideas and the sample datasets separate
> because 1) we do not know when GRASS 7 will be released and 2) the
> additional datasets you listed below are very interesting, also for
> GRASS 6.x. Therefore I would tend to add any new datasets to
> http://grass.osgeo.org/wiki/Sample_datasets
> even though this is currently for downloads only, but the two main
> sites for sample data download are
> http://grass.osgeo.org/download/data.php
> and
> http://www.grassbook.org/data_menu3rd.php
> so it could be ok to add new ideas and TODO's to the wiki?

I have updated http://grass.osgeo.org/wiki/Sample_datasets


Markus M

> I like the idea of having separately downloadable mapsets for the two
> existing sample locations. This keeps download size manageable and
> users can pick the sample data they are interested in. Of course
> additional sample locations are also an option and I think that there
> are already some new sample locations in preparation, e.g. for Italy.
> Another issue are the examples based on the sample data, both in the
> book and in the documentation. All the examples for vector network
> analysis that use cost columns are wrong. I am busy updating the
> v.net.* manuals for GRASS 7 and will (hopefully) soon backport the
> manuals to 6.5 and 6.4. Other examples in the manuals, and the manuals
> themselves, may need a closer look too...
> With regard to GRASS 7 vector format, I want to change it further and
> would therefore postpone a GRASS 7 sample dataset a bit.
> Forward/backward compatibility will be limited: rebuilding topology
> will be required when switching from 6.x to 7 or back (currently GRASS
> 6.x can read GRASS 7 vectors as they are). For the existing sample
> datasets spearfish and nc_spm, v.build.all takes less than a minute on
> my laptop (6.x and 7), so this is not really an obstacle.
> For external file formats, we could also provide more links to free
> datasources, however, examples based on these data may not work when
> these datasources are updated.
> Markus M
>> Feel free to post it on wiki (or suggest where it would fit and I will post it).
>> After I get some feedback I will prepare the first version of the new mapsets for networks and timeseries
>> to test whether they are suitable,
>> thanks, Helena
>> ------------------------------------------------------------------------------------------------
>> Prepare new data sets (grass7 vector format?):
>> - provided as separate MAPSETS that can be inserted into nc_spm_08 or gisdemo_ncspm (or their grass7 versions)
>> - packaged all into single location (nc_spm_11) which could reach 1GB.
>> - each MAPSET will have an example of application
>> proposed new MAPSETS:
>> Road and street networks (nconemap, ncdot)
>> http://www.ncdot.org/it/gis/DataDistribution/DOTData/default.html
>> LRS road network, Integrated Statewide Road network, Bike Paths
>> - streets for wake http://www.wakegov.com/gis/services/data.htm`
>> -add boundaries and POI for reference?
>> -include emergency centers ? hurricane evacuation routes? potential emergency shelters?
>> -include stream network?
>> Time_series_coast
>> coastal lidar point clouds, 1m res DEMs, orthos, 15 years in 10-15 snapshots
>> extended version of this
>> http://courses.ncsu.edu/mea582/common/media/01/NagsHead_series.zip
>> also used for coastal analysis toolbox add-ons
>> Landuse_img
>> new 4 channel 1m res 2009 imagery NAID
>> new NLCD 2006 from USGS and NLCD2001
>> 0.15m res ortho?
>> include any post storm, post hurricane, post flood imagery for training purposes?
>> see example here:
>> http://www.ncdot.org/it/gis/DataDistribution/SpecialData/NCStormDamageAndCleanup.html
>> Time_series_census
>> this may take more time to prepare,
>> data are available for 1970,80,90,2000,2010
>> combine with election districts?
>> - cleanup and provide nc_ll, nc_utm, nc_spf for testing projections
>> EXTERNAL data sets for testing external data formats
>> - point cloud asci, las
>> - shape
>> - geodatabase?
>> - MRsid, geotiff?
>> Anything else from here?
>> http://courses.ncsu.edu/mea582/common/GIS_anal_lecture/GIS_Anal_webdata.html
>> http://www.nconemap.com/Default.aspx?tabid=286
>> http://www.wakegov.com/gis/services/data.htm
>> (we provide link to this so only data to be used for GRASS tutorials and testing should be in the data set)
>> On Jun 20, 2011, at 11:15 AM, Markus Metz wrote:
>>> Hi all,
>>> we may want to think about an update of the sample datasets. I have
>>> recently updated the documentation of the v.net.* modules including
>>> examples and noticed that roads digitized as multilanes have wrong
>>> line directions, i.e. not matching drive directions. This makes
>>> assignment of different forward/backward costs impossible. The vector
>>> map roads in nc_spm_08 should also get a new layer with unique
>>> category values. The updated, correct examples are anything but
>>> intuitive and would be much shorter and simpler with already existing
>>> unique categories in roads at PERMANENT.
>>> Helena also mentioned the LiDAR-based DEM in nc_spm_08 which needs to
>>> be expanded. With the development of a test suite for G7, I am sure
>>> that there will be more requests for updates of the sample datasets.
>>> Time for a TODO list somewhere?
>>> Markus M

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