The Data

Project data is organized into layers. Each layer contains data related to a specific theme. Layers are superimposed on one another to form the map that is displayed in the interface.

Some layers are comprised of objects or elements that are represented using a type of geometry (points, lines, polygons) and descriptive attributes. For example, a layer can represent trees using points, and the attributes associated with them can include the species of tree, diameter, height, and state of health. Thus, each object (tree) of the layer has a geometry that is located in space and attributes that describe it.

Other layers are comprised of raster data (pixels) that form images, such as aerial photographs, satellite images or digital elevation models.

Layers can be grouped hierarchically based on themes, such as urban planning, the environment, transportation, etc. A multi-level hierarchical structure makes it easier to work with projects when they contain many layers and different themes.

Some layers are called base maps because they provide a context to display the data layers. Interaction with base maps is limited to selecting the base map to be displayed in the application.