1helptext(1) GRASS GIS User's Manual helptext(1)
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6 When launching GRASS GIS for the first time, you will open a default
7 Location "world_latlog_wgs84" where you can find a map layer called
8 "country_boundaries" showing a world map in the WGS84 coordinate sys‐
9 tem.
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11 The main component of the Data tab is the Data Catalog which shows the
12 GRASS GIS hierarchical structure consisting of Database , Location and
13 Mapset .
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15 Â GRASS Database (directory with projects)
16 Running GRASS GIS for the first time, a folder named "grassdata" is
17 automatically created. Depending on your operating system, you can
18 find it in your $HOME directory (*nix) or My Documents (MS Win‐
19 dows).
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21 Â Location (a project)
22 A Location is defined by its coordinate reference system (CRS). In
23 the case of the default Location, it is a geographic coordinate
24 reference system WGS84 (EPSG:4326). If you have data in another CRS
25 than WGS84, you should create a new Location corresponding to your
26 system.
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28 Â Mapset (a subproject)
29 Each Location can have many Mapsets for managing different aspects
30 of a project or project’s subregions. When creating a new Location,
31 GRASS GIS automatically creates a special Mapset called PERMANENT
32 where the core data for the project can be stored.
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34 For more info about data hierarchy, see GRASS GIS Database page.
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37 First, if you would like to get to know GRASS better before importing
38 your own data, please download provided samples such as the "North Car‐
39 olina" dataset. You can simply reach them through "Download sample lo‐
40 cation to current database" management icon .
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42 To work with your own data, you typically want to first create a new
43 Location with a coordinate reference system (CRS) suitable for your
44 study area or one that matches your data’s CRS. The Location Wizard
45 will help you with that by guiding you through a series of dialogs to
46 browse and select predefined projections (also via EPSG code) or to de‐
47 fine individual projections.
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49 Creating a New Location with the Location Wizard
50 If you know the CRS of your data or study area, you can fill EPSG code
51 or description and Location Wizard finds appropriate CRS from a prede‐
52 fined list of projections. If you do not know CRS of you data, you can
53 read it from your georeferenced data file (e.g. shapefile or GeoTiff
54 file with the related metadata properly included).
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56 Importing data
57 After creating a new Location, you are ready to import your data. You
58 can use simple raster or vector data import , or a variety of more spe‐
59 cialized tools. If the data’s CRS does not match your Location’s CRS,
60 data will be automatically reprojected. After import your raster or
61 vector data are added as a layer to Map Display. To change layer prop‐
62 erties, go to Display tab. To analyze your data, search for a tool in
63 the Modules tab.
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66 GRASS GIS can be run entirely without using the graphical user inter‐
67 face. See examples of running GRASS GIS from a command line.
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70 GRASS GIS 8 Reference Manual
71 GRASS GIS 8 startup program manual page
72 GRASS GIS tutorials and books
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74 List of EPSG codes (Database of worldwide coordinate systems)
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76 Main index | Topics index | Keywords index | Graphical index | Full in‐
77 dex
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79 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
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83GRASS 8.2.0 helptext(1)