GRASS-Wiki - User contributions [en]

ASTER topography

2011-03-17T09:55:45Z

⚠️Alicethomas:

== 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]

== Steps to import 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

'''Note 1:''' You can also mosaic all tiles with gdalwarp and wildcards:
gdalwarp AST*.tif mosaic.tif

'''Note 2:''' Experimenting on color rules that 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"]. Some color rules to start with...

# 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

== See also ==

* http://gis.fem-environment.eu/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://www.customwritinghelp.co.uk/assignment.php assignment writing]
* [http://www.perfectwriting.co.uk/assignment/assignment-help.php assignment help]
* [http://www.perfectwriting.co.uk/assignment/assignment-writing.php assignment writing]

[[Category: FAQ]]
[[Category: Geodata]]

Import DXF

2011-03-17T09:54:17Z

⚠️Alicethomas:

This page describes how to import file in {{wikipedia|AutoCAD DXF}} format into GRASS using {{cmd|v.in.dxf}}. DXF usually contains more layers. You can convert DXF file to ''multi-layer'' [[GRASS Vector Layers|GRASS vector map]] or import selected DXF layers as ''separated'' (single layer) GRASS vector maps.
__TOC__
== Convert DXF layers to multi-layer GRASS vector map ==

Run from menu

File -> Import vector map -> DXF import

or from command-line

v.in.dxf

<center>
{|
| [[Image:v-in-dxf-1.png|thumb|400px|Choose input DXF file]] || [[Image:v-in-dxf-2.png|thumb|400px|Optionally list DXF layers which to import (by default all layers are imported)]]
|}
</center>

Optionally you can also import all DXF layers to single layer GRASS vector map (<code>-1</code> flag).

== Convert DXF layers to separate GRASS vector maps ==

Run from menu

File -> Import vector map -> Multiple DXF layers import

[[Image:v-in-dxf-3.png|thumb|center|500px|Choose input DXF file and DXF layers to be imported. Each selected DXF layer is imported as single layer GRASS vector map.]]

== Tips ==

The concepts of areas, boundaries and lines in CAD and GIS are different, before importing a drawing into a GIS try to make it clean and "GIS like". Ex: Make that two areas share the same boundary, join lines and convert to polylines, remove duplicated objects.

Also import only the objects of interest, do not import text, paper layout or hatches.

Separate the objects that will become lines or boundaries into different layers.

If your dxf is in a local coordinate system (like old topo drawings) with shifting parameters you can use {{cmd|v.transform}} or you can put it in place with a CAD software (align) and them import into GRASS. If it already have an UTM coordinate and you want to change the reference system (datum) create the corresponding location import, change location and then use {{cmd|v.proj}}.
* [http://www.designerevaluation.com/logo-design/ logo design]
* [http://www.designerevaluation.com/ website design]

[[Category:Documentation]]
[[Category:FAQ]]
[[Category:wxGUI]]

GRASS-Wiki

2011-03-17T09:52:21Z

⚠️Alicethomas:

__NOTOC__
{| width="100%"
|-
| width="68%" style="vertical-align:top" |
<div style="margin:0; margin-right:10px; border:1px solid #dfdfdf; background-color:#f8f8ff;">

<div style="padding:0.3em 1em 0.7em 1em;">

[[Image:grasslogo_vector_small.png|right|link=http://grass.osgeo.org]]

=== Welcome to the GRASS GIS Users Wiki ===

{{website|intro/general.php|'''GRASS GIS'''}} is a [http://en.wikipedia.org/wiki/Geographic_information_system Geographic Information System] used for geospatial data management and analysis, image processing, graphics/map production, spatial modeling, and visualization.

On this Wiki, you can get and contribute to GRASS related information, documents and community provided add-ons programs. To edit here, you need to register and login first (see top right link).

For GRASS at a glance, see [[Core features]]. For usage examples, see the [http://grass.osgeo.org/screenshots/index.php screenshots gallery] and [[Applications]].
</div>
</div>

<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#FFE5E5;">
'''What's hot:'''
* [[GRASS Community Sprint Prague 2011]] - 20-25 May 2011, Prague, Czech Republic
* [http://grass.osgeo.org/download/ '''GRASS 6.4.0 released''' - get it now!] along with the [[Quick wxGUI tutorial]]
* New [[Initiatives]]
* [http://www.osgeo.org/node/1069 Helena Mitasova Receives Sol Katz Award 2010]
</div>

<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">
==== User Documentation and Support ====
* [[GRASS Help|GRASS Help and Getting Started]]
* [[GRASS Documents|In depth GRASS Documentation]]
* [[Installation Guide]] for precompiled binaries
* [[Faq|FAQ]] - Frequently Asked Questions
* [[Applications]] - use cases of GRASS in various disciplines
* [[wxGUI]] - Graphical User Interface based on wxPython
</div>

<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">

==== Community ====
* [[GRASS Community]]: Getting in touch
* [[Applications|Research applications]]: What people are doing with GRASS
* [[GRASS migration hints|Migrating to GRASS]]
* [[GRASS Blogger]]
* Get involved: [[Project jobs]]
* [http://grass.osgeo.org/wiki/Special:Recentchanges?feed=rss RSS feed] of recent changes of this Wiki
</div>

<div>Have a look at the GRASS GIS users worldwide [http://grass.osgeo.org/community/ GRASS GIS User Online]. If you operate a GRASS GIS installation, you are welcome to enter your user data there.
</div>

<div><p>''[[GRASS-Wiki:Language policy|Translate this Wiki]]''</p></div>


| width="38%" style="vertical-align:top" |
<div style="margin:0; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">
[[Image:OSGeo 220pix.png|center|220px|link=http://www.osgeo.org]]
<center>OSGeo Foundation Project</center>
</div>

<div style="margin:0; margin-top:10px; border:1px solid #dfdfdf; padding:1em 1em 1em 1em; background-color:#f8f8ff;">
[[Image:Btn_donate_SM.gif|center|link=http://grass.osgeo.org/donation.php]]<center>[http://grass.osgeo.org/donation.php Donate via PayPal.com]</center>
</div>

<div style="margin:0; margin-top:10px; border:1px solid #dfdfdf; padding: 0em 1em 1em 1em; background-color:#f8f8ff;">
* [http://grass.osgeo.org/screenshots/index.php GRASS Screenshots]
* [http://trac.osgeo.org SVN/trac] Source Code Repository
* [http://grass.osgeo.org/community/support.php Mailing lists] and [http://grass.osgeo.org/community/support.php#irc IRC]
* [http://trac.osgeo.org/grass/ Report errors or wishes]
* [https://svn.osgeo.org/grass/grass/branches/releasebranch_6_4/COPYING Licensed under GNU GPL]
* [http://www.seoprofessionalsonline.com professional seo]
* [http://www.seoprofessionalsonline.com/website-optimizer.asp website optimizer]
* [http://www.realsofttech.com/ web design service]
</div>

<div style="margin:0; margin-top:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">

==== Download ====
* [http://grass.osgeo.org/download/ Source code and binaries]
* '''[[GRASS AddOns]]'''
* [[Promotional material]]
* [[Sample datasets]]
* [[Global datasets]]
</div>

<div style="margin:0; margin-top:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">

==== Development ====
* [[Compile and Install]] of Source Code
* [[Development|GRASS Development]] intro
* [http://trac.osgeo.org/grass/wiki GRASS-trac]: the development Wiki, bugtracker, source code browser
* [[Release Roadmap]]
* [[GRASS 7 ideas collection]]
* [[GRASS SoC Ideas|Google Summer of Code ideas collection]]
* [http://trac.osgeo.org/grass/wiki/HowToContribute How to contribute to GRASS development] (getting write access and such)
</div>

<div style="margin:0; margin-top:10px; border:1px solid #dfdfdf; padding:0em 1em 1em 1em; background-color:#f8f8ff;">
Project Metrics provided by [http://www.ohloh.net/projects/3666 Ohloh].
{{#ohloh: account=3666}}
</div>
|}