Unit 02 - First steps


Starting a GRASS session requires basic knowledge about software itself, the users usually do not like it ;-) In other words GRASS forces organizing your data from early beginning.

Before entering GRASS a startup screen appears, the user must define working project in which GRASS session will operate. Without this step you cannot enter GRASS. This approach is not so common. Applications like Esri ArcGIS or QGIS just starts. The user loads different data from various data sources in different projections, and starts working on his/her project. GRASS is different, which makes this software harder to enter for newcomers. But don’t worry, we will enter GRASS in few steps.

The GRASS GIS startup screen requires to set up three items:

  1. Database directory. A directory on local or network disc which contains all data accessed by GRASS. It’s usually directory called grassdata located in user’s home directory. This item is set up on Windows automatically, so usually you don’t need to care.
  2. Location. Plays a role of “a project”. All geodata stored within one location must have the same spatial coordinate system (GRASS doesn’t support on-the-fly projection).
  3. Mapset Contains task-related data within one project. Helps organizing data into logical groups or to separate parallel work of more users on the same project.