ASTER topography: Difference between revisions
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<div class="boilerplate metadata" id="attention" style="-moz-border-radius:30px; border: 1px double #35824B; margin-bottom: 1.5em; padding: 1em; background-color: #f9f9f9;"> | |||
<p style="font-size: 150%; text-align: left;"><span style="color:#35824B">'''Attention'''</span> </p><span style="color:#303030">'''The following instructions concern the first release of the ASTER GDEM data base. The public distribution of a second, much improved version, started in October 2011 (refer to [http://www.jspacesystems.or.jp/e/ Japan Space Systems'] [http://www.jspacesystems.or.jp/ersdac/GDEM/E/ ASTER GDEM dedicated website] for [http://www.jspacesystems.or.jp/ersdac/GDEM/E/4.html details] and [http://www.jspacesystems.or.jp/ersdac/GDEM/ver2Validation/Summary_GDEM2_validation_report_final.pdf a high-level validation study]).'''</span> | |||
</div> | |||
== Download == | |||
The one-by-one-degree tiles can be downloaded | |||
* from [https://wist.echo.nasa.gov/~wist/api/imswelcome/ NASA's EOS data archive] and/or | |||
* from [http://www.gdem.aster.ersdac.or.jp/ Japan's Ground Data System] | |||
== Importing ASTER GDEM tiles in GRASS' data base == | |||
=== Mosaicking ASTER GDEM tiles === | |||
Mosaicking all tiles can be done with <code>gdalwarp</code> and <code>wildcards</code>: <source lang="bash"> | |||
gdalwarp AST*.tif aster_mosaic.tif</source> | |||
The big <code>aster_mosaic.tif</code> can be imported in GRASS' data base as usual by using the <code>r.in.gdal</code> module. | |||
=== Importing individual ASTER GDEM tiles in GRASS === | |||
<source lang="bash"> | |||
# save downloaded zip files in one directory | # save downloaded zip files in one directory | ||
# enter in directory and unzip files at once | # enter in directory and unzip files at once | ||
Line 18: | Line 37: | ||
# assign colors | # assign colors | ||
r.colors aster_gdem color=terrain | r.colors aster_gdem color=terrain | ||
</source> | |||
== Special color rules == | |||
Below are some starter color rules attempting to replicate NASA's [http://www.nasa.gov/images/content/363790main_PIA12090_gdem-press-colorized-topo.tif "GDEM press colorized topo"] published at [http://www.nasa.gov/topics/earth/features/20090629.html "Mission News"]. | |||
<source lang="bash"> | |||
# create a file (named for example '''aster_gdem''') | |||
# under the directory '''/etc/colors''' | |||
# within the local grass installation (e.g. '''/usr/local/grass-6.4.0svn/etc/colors/aster_gdem''') | |||
# copy-paste the following rules | # copy-paste the following rules | ||
-11000 black | -11000 black | ||
Line 49: | Line 72: | ||
5500 255 255 255 | 5500 255 255 255 | ||
nv white | nv white | ||
# apply colors | # apply colors | ||
r.colors aster_gdem color=aster_gdem | r.colors aster_gdem color=aster_gdem | ||
</source> | |||
== See also == | |||
* http://gis.cri.fmach.it/aster-gdem-quality/ | |||
* https://arrowsmith.blog.asu.edu/2009/07/27/looking-at-the-new-aster-30-m-dems-not-so-impressive-relative-to-srtm-90-m | |||
* http://www.geomorphometry.org/content/gdem-quick-assessment | |||
* [http://grasswiki.osgeo.org/wiki/Global_datasets#ASTER_topography_.28GDEM_V2.29 GRASS-Wiki entry about ASTER GDEM v2] | |||
[[Category: | [[Category: Geodata]] | ||
[[Category: Tutorial]] | |||
[[Category: Import]] |
Latest revision as of 07:48, 19 February 2013
Download
The one-by-one-degree tiles can be downloaded
- from NASA's EOS data archive and/or
- from Japan's Ground Data System
Importing ASTER GDEM tiles in GRASS' data base
Mosaicking ASTER GDEM tiles
Mosaicking all tiles can be done with gdalwarp
and wildcards
:
gdalwarp AST*.tif aster_mosaic.tif
The big aster_mosaic.tif
can be imported in GRASS' data base as usual by using the r.in.gdal
module.
Importing individual ASTER GDEM tiles in GRASS
# save downloaded zip files in one directory
# enter in directory and unzip files at once
unzip "*.zip"
# create WGS84 location, import elevation (=dem) and quality (=num) tiles in PERMANENT mapset
for GDEM in *.tif ; do
r.in.gdal in=$GDEM out=`basename ${GDEM} .tif`
done
# match region to extent of imported gdem tiles
g.region rast=`g.mlist pat=AST*dem sep=,` -p
# patch tiles in one map
r.patch in=`g.mlist pat=AST*dem sep=,` out=aster_gdem
# assign colors
r.colors aster_gdem color=terrain
Special color rules
Below are some starter color rules attempting to replicate NASA's "GDEM press colorized topo" published at "Mission News".
# create a file (named for example '''aster_gdem''')
# under the directory '''/etc/colors'''
# within the local grass installation (e.g. '''/usr/local/grass-6.4.0svn/etc/colors/aster_gdem''')
# copy-paste the following rules
-11000 black
-500 0 0 10
-300 0 0 20
-200 0 0 70
-100 0 0 130
-50 0 0 205
0 black
0.1 123 123 164
50 123 123 255
100 41 156 41
160 164 180 41
350 230 230 41
610 164 205 41
1100 164 213 41
1200 213 255 148
1500 205 255 139
2000 215 255 155
2300 238 238 24
3000 255 255 0
3800 255 213 41
4000 255 150 0
5500 255 255 255
nv white
# apply colors
r.colors aster_gdem color=aster_gdem