Introduction to GRASS GIS and QGIS
Institute for Environmental and Spatial Analysis...University of North Georgia
1 Open sauce?
2 Open source
Images under Creative Commons Licenses
3 Why open source?
Open source software | Commercial software | |
---|---|---|
Cost | 0 | \$\$\$ (e.g., ArcHydro: Single Use ArcGIS for Desktop Standard \$7,000 + Spatial Analyst \$2,500 = \$9,500) |
Support | User & developer communities | Commercial support, User community |
Troubleshooting | Report to the community, Fix yourself, Hire developers | Report to the company, Wait for free or paid updates if any |
UI | Lack of user friendliness, Learning curve | User friendly, Familiar |
Algorithms | Peer reviewed, Scientifically proven, Transparent | Black box, Only indirectly known through documents |
Extensibility | API, Open data formats, Can be integrated with other open source software (e.g., QGIS+GRASS) | API, Proprietary SDK, Proprietary data formats |
Summary | Low cost, May require expert help | High cost, Can use commercial support |
4 Open source GIS
5 GRASS GIS
GRASS (Geographic Resources Analysis Support System)
Celebrated its 36 years in 2019!
First released on July 29, 1983 by the U. S. Army Corps of Engineers’ Construction Engineering Research Laboratory (USA/CERL)
In 1999, released under the GNU General Public License (an open source license)
Over 350 modules
Provides scientific modules to QGIS as plugins
Written in C, C++, Python, and wxPython
Python API
6 QGIS
Started as Quantum GIS in early 2002 by Gary Sherman
Integrates GRASS GIS modules for scientific analysis
More similar to ArcGIS 10 than to ArcGIS Pro
- Single map pane
- No ribbon UI, luckily!
Uses Coordinate Reference Systems (CRS)
Written in C++, Qt, and Python