GRASS-Wiki - User contributions [en]

LIDAR

2006-12-04T12:58:31Z

⚠️C716263: /* Other */

<h1> LIDAR and Multi-beam Swath bathymetry data </h1>

== Modules ==

=== Import ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.in.xyz.html r.in.xyz] - Create a raster map from an assemblage of many coordinates using univariate statistics. ([http://hamish.bowman.googlepages.com/grassfiles#xyz example])

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.in.ascii.html v.in.ascii] - Import data from an ASCII file to GRASS vector format. ''Limited to a few million data points unless topology and database creation is skipped with '-b' flag''

=== Analysis ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.edgedetection.html v.lidar.edgedetection] - Detect the object's edges from a LIDAR data set.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.growing.html v.lidar.growing] - Building contour determination and Region Growing algorithm for determining the building inside.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.correction.html v.lidar.correction] - Correction of the v.lidar.growing output. It is the last of the three algorithms for LIDAR filtering.

=== Surface generation ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.surf.rst.html v.surf.rst] - Spatial approximation and topographic analysis using regularized spline with tension.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.surf.idw.html v.surf.idw] - Surface interpolation from vector point data by Inverse Distance Squared Weighting.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.fillnulls.html r.fillnulls] - Fills no-data areas in raster maps using v.surf.rst splines interpolation.

== Swath Bathymetry Tools ==

* The [http://david.p.finlayson.googlepages.com/swathwidth v.swathwidith] module by David Finlayson for planning surveys. (development page)

* An example of [http://bambi.otago.ac.nz/hamish/grass/gdal/sidescan_warp.html post-processing scanned paper sidescan swaths] using thin plate spline warping with [http://www.gdal.org/ GDAL's] "<tt>gdalwarp -tps</tt>" function. (debugging page)

== LIDAR Tools ==

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.terraflow.html r.terraflow] - computation of flow direction, flow accumulation and other basic topographic terrain indices from massive raster digital elevation models (DEM). From the Duke University [http://terrain.cs.duke.edu/ STREAM] project.

* [http://mpa.itc.it/markus/grass61/demos/rlake/ Flood simulation] using [http://grass.ibiblio.org/grass63/manuals/html63_user/r.lake.html r.lake]. Includes fancy NVIZ visualization of Trento, Italy, by Markus Neteler.

== Sample data ==

=== Widely used in GRASS tutorials ===

* [http://mpa.itc.it/grasstutor/data_menu2nd.phtml Jockey's Ridge, NC, LIDAR dataset]

=== Other ===

* United States Antarctic Resource Center: LIDAR High-resolution DEM Final DATA Downloads http://usarc.usgs.gov/lidar_dload.shtml

* LIDAR ALSM Research, Arizona State University Ative Tectonics, Research Group http://lidar.asu.edu/research.html and http://www.geongrid.org/science/lidar.html

* USGS Center for LIDAR Information Coordination and Knowledge (aka CLICK) - USGS LiDAR point cloud distribution site http://lidar.cr.usgs.gov

* Washington State Geospatial Data Archive, Mount Saint Helens - Lidar Data https://wagda.lib.washington.edu/data/type/elevation/lidar/st_helens/

* Puget Sound Lidar Consortium, public-domain high-resolution topography for western Washington http://pugetsoundlidar.ess.washington.edu/index.htm

* NOAA Topographic Change Mapping LIDAR Data Retrieval Tool (LDART) NOAA Coastal Services Center http://maps.csc.noaa.gov/TCM/

* Landmap, LIDAR Data from the Environment Agency http://www.landmap.ac.uk/lidar/lidar.html

* Northern California LIDAR data http://quake.usgs.gov/research/geology/lidar/ and http://core2.gsfc.nasa.gov/lidar/terrapoint/

* IDAHO GEOSPATIAL , Bare Earth LIDAR DEM Download - UTM http://inside.uidaho.edu/geodata/LiDAR/LiDARBareEarthDEM_DownloadUTM.htm

* EarthScope Spatial Data Explorer - A java application for querying, browsing, and acquiring data from the EarthScope Spatial Data Repository. Currently includes a number of LiDAR datasets. http://www.earthscope.org/data/lidar.php

* LIDAR Galley https://peoiewswebinfo.monmouth.army.mil/JPSD/LIDAR_Gallery.htm

* South Tyrol - Download of DTMs (Homepage in German or Italian) http://www.provinz.bz.it/raumordnung/grundkarten/utm/default_d.htm

LIDAR

2006-12-04T12:57:23Z

⚠️C716263: /* Other */

<h1> LIDAR and Multi-beam Swath bathymetry data </h1>

== Modules ==

=== Import ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.in.xyz.html r.in.xyz] - Create a raster map from an assemblage of many coordinates using univariate statistics. ([http://hamish.bowman.googlepages.com/grassfiles#xyz example])

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.in.ascii.html v.in.ascii] - Import data from an ASCII file to GRASS vector format. ''Limited to a few million data points unless topology and database creation is skipped with '-b' flag''

=== Analysis ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.edgedetection.html v.lidar.edgedetection] - Detect the object's edges from a LIDAR data set.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.growing.html v.lidar.growing] - Building contour determination and Region Growing algorithm for determining the building inside.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.lidar.correction.html v.lidar.correction] - Correction of the v.lidar.growing output. It is the last of the three algorithms for LIDAR filtering.

=== Surface generation ===

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.surf.rst.html v.surf.rst] - Spatial approximation and topographic analysis using regularized spline with tension.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/v.surf.idw.html v.surf.idw] - Surface interpolation from vector point data by Inverse Distance Squared Weighting.

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.fillnulls.html r.fillnulls] - Fills no-data areas in raster maps using v.surf.rst splines interpolation.

== Swath Bathymetry Tools ==

* The [http://david.p.finlayson.googlepages.com/swathwidth v.swathwidith] module by David Finlayson for planning surveys. (development page)

* An example of [http://bambi.otago.ac.nz/hamish/grass/gdal/sidescan_warp.html post-processing scanned paper sidescan swaths] using thin plate spline warping with [http://www.gdal.org/ GDAL's] "<tt>gdalwarp -tps</tt>" function. (debugging page)

== LIDAR Tools ==

* [http://grass.ibiblio.org/grass63/manuals/html63_user/r.terraflow.html r.terraflow] - computation of flow direction, flow accumulation and other basic topographic terrain indices from massive raster digital elevation models (DEM). From the Duke University [http://terrain.cs.duke.edu/ STREAM] project.

* [http://mpa.itc.it/markus/grass61/demos/rlake/ Flood simulation] using [http://grass.ibiblio.org/grass63/manuals/html63_user/r.lake.html r.lake]. Includes fancy NVIZ visualization of Trento, Italy, by Markus Neteler.

== Sample data ==

=== Widely used in GRASS tutorials ===

* [http://mpa.itc.it/grasstutor/data_menu2nd.phtml Jockey's Ridge, NC, LIDAR dataset]

=== Other ===

* United States Antarctic Resource Center: LIDAR High-resolution DEM Final DATA Downloads http://usarc.usgs.gov/lidar_dload.shtml

* LIDAR ALSM Research, Arizona State University Ative Tectonics, Research Group http://lidar.asu.edu/research.html and http://www.geongrid.org/science/lidar.html

* USGS Center for LIDAR Information Coordination and Knowledge (aka CLICK) - USGS LiDAR point cloud distribution site http://lidar.cr.usgs.gov

* Washington State Geospatial Data Archive, Mount Saint Helens - Lidar Data https://wagda.lib.washington.edu/data/type/elevation/lidar/st_helens/

* Puget Sound Lidar Consortium, public-domain high-resolution topography for western Washington http://pugetsoundlidar.ess.washington.edu/index.htm

* NOAA Topographic Change Mapping LIDAR Data Retrieval Tool (LDART) NOAA Coastal Services Center http://maps.csc.noaa.gov/TCM/

* Landmap, LIDAR Data from the Environment Agency http://www.landmap.ac.uk/lidar/lidar.html

* Northern California LIDAR data http://quake.usgs.gov/research/geology/lidar/ and http://core2.gsfc.nasa.gov/lidar/terrapoint/

* IDAHO GEOSPATIAL , Bare Earth LIDAR DEM Download - UTM http://inside.uidaho.edu/geodata/LiDAR/LiDARBareEarthDEM_DownloadUTM.htm

* EarthScope Spatial Data Explorer - A java application for querying, browsing, and acquiring data from the EarthScope Spatial Data Repository. Currently includes a number of LiDAR datasets. http://www.earthscope.org/data/lidar.php

* LIDAR Galley https://peoiewswebinfo.monmouth.army.mil/JPSD/LIDAR_Gallery.htm

* South Tyrol - Download of DTMs http://www.provinz.bz.it/raumordnung/grundkarten/utm/default_d.htm

GRASS and Shell

2006-07-08T16:09:08Z

⚠️C716263: /* Parallel GRASS jobs */

It is fairly easy to write a GRASS job as Shell script which launches GRASS, does the operation and cleans up the temporary files.

=== Setting the variables ===

You have to set a couple of variables to enable GRASS command to run:

# Example in bash shell syntax:

# path to GRASS binaries and libraries:
export GISBASE=/usr/local/grass60

export PATH=$PATH:$GISBASE/bin:$GISBASE/scripts
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$GISBASE/lib

# use process ID (PID) as lock file number:
export GIS_LOCK=$$

# settings for graphical output to PNG file (optional)
export GRASS_PNGFILE=/tmp/grass6output.png
export GRASS_TRUECOLOR=TRUE
export GRASS_WIDTH=900
export GRASS_PNG_COMPRESSION=1

The following variable defines where the GRASS settings file is stored. This can be anywhere on the system. You could also generate the '.grassrc6' on the fly in your script, even with different name. Just indicate it correctly:

# path to GRASS settings file
export GISRC=$HOME/.grassrc6

Now you can test:

# this should print the GRASS version used:
g.version
# other calculations go here ...

You should cleanup internal tmp files like this:

# run GRASS' cleanup routine
$GISBASE/etc/clean_temp

# remove session tmp directory:
rm -rf /tmp/grass6-$USER-$GIS_LOCK

If this works, you can launch other GRASS commands. The approach works within Shell scripts and also in the command line terminal.

=== Example ===

* GRASS shell script job to generate a [http://grass.itc.it/spearfish/grass_earthquakes.sh Recent Earthquakes Map]

=== Parallel GRASS jobs ===

If you want to launch several GRASS jobs in parallel, you have to launch each job in its own mapset. Be sure to indicate the mapset correctly in the GISRC file (see above). You can use the process ID (PID, get with $$) to generate a almost unique number which you can add to the mapset name.

Now you could launch the jobs on an [http://openmosix.sourceforge.net/ openMosix cluster] (just install openMosix on your colleague's computers...).

=== See also ===

* [http://grass.itc.it/grass61/manuals/html61_user/variables.html#gisenv Other GRASS variables]

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