Grass Tutorial Moritz Lennert [email protected] Grass Tutorial by Moritz Lennert Published $Date: 2005/04/26 15:39:13 $ Geographic Resources Analysis Support System Tutorial (Please note, the current version only outlines the intended contents, pages may be missing!) Copyright (c) 2003 GRASS Development Team. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". Table of Contents I. Introduction........................................................................................................................1 1. About this tutorial....................................................................................................1 2. What is GRASS ? ......................................................................................................3 3. Credits........................................................................................................................5 II. Basics..................................................................................................................................7 4. Hardware and software requirements ..................................................................7 Hardware .............................................................................................................7 Basic Software .....................................................................................................7 Optional software ...............................................................................................7 5. Basic UNIX reference .............................................................................................11 6. Download and Install ............................................................................................13 Packages of GNU/Linux Distributions.........................................................13 Compilation of source code.............................................................................13 III. GRASS in 10 minutes - Quick Intro for Newbies .................................................15 7. How to Quickstart GRASS....................................................................................15 You have a GRASS database ...........................................................................15 You have a georeferenced data file, and know its geographical coordinates...............................................................................................16 You have a georeferenced raster file, but don’t know its geographical coordinates...............................................................................................16 You have a non-georeferenced data file ........................................................17 Other situations.................................................................................................17 8. The Most Important Commands to Get Started ................................................19 IV. GRASS Concepts..........................................................................................................21 9. GRASS structure.....................................................................................................21 10. GRASS commands ...............................................................................................23 11. Graphical User Interface .....................................................................................25 12. The GRASS Region ..............................................................................................27 What is the region.............................................................................................27 Why care about the region ..............................................................................27 How to work with the region .........................................................................27 How to change the default region..................................................................28 V. Start a Project..................................................................................................................31 13. Set-up your GRASS database .............................................................................31 14. Start running GRASS ...........................................................................................33 15. Planning and constructing a GRASS database ................................................35 General definition of a project area when using scanned maps ................35 Definition of a project area with predefined geographical resolution......36 Definition of the project area without a previously defined resolution ...37 16. Set-up your location.............................................................................................39 17. Manage your data ................................................................................................43 VI. Import Data ...................................................................................................................45 18. Supported formats ...............................................................................................45 19. Raster Import ........................................................................................................47 20. Vector Import ........................................................................................................49 21. Sites (point data) import......................................................................................51 VII. Display and Query Maps..........................................................................................53 22. Managing GRASS Monitors ...............................................................................53 Frames in monitors...........................................................................................53 23. Displaying Maps ..................................................................................................55 Colors .................................................................................................................55 Scripting the display of maps (and frames)..................................................55 24. Zooming and Panning.........................................................................................57 25. Adding Legends and Scales................................................................................59 26. Visualize in 3D with nviz ....................................................................................61 iii VIII. Digitize........................................................................................................................63 27. Digitizing Vector Maps........................................................................................63 Rules for Digitizing in Topological GIS.........................................................63 Digitizing Maps ................................................................................................63 Digitizing Areas ................................................................................................64 Digitizing of Elevation Isolines ......................................................................66 28. Processing Scanned Maps...................................................................................69 Geocoding of scanned maps ...........................................................................69 Gap free geocoding of multiple, adjacent, scanned maps ..........................72 IX. Manage Attributes and Classes .................................................................................75 29. Raster Categories and Attributes.......................................................................75 Viewing category values..................................................................................75 Changing category values...............................................................................75 30. Vector Categories and Attributes.......................................................................77 Viewing category values..................................................................................77 Changing category values...............................................................................77 31. Site Attributes .......................................................................................................79 32. Data Management with PostgreSQL.................................................................81 X. Analyze Maps .................................................................................................................83 33. Statistics and Reports...........................................................................................83 Modules for raster maps..................................................................................83 Modules for vector maps.................................................................................84 Modules for site maps......................................................................................84 34. Overlay and Patch Maps.....................................................................................87 35. Create Buffers........................................................................................................89