Terminology

OrbisGIS organizes geographic data into a series of layers. A layer can be simple (BasicLayer) or composite (LayerCollection)

       

BasicLayer

A BasicLayer is an heterogeneous collections of geographic objects and their symbolic representation (Style). Geographic objects can represent some geometry features such as parcels and some raster data such as  orthophoto imagery or raster-based digital elevation models. The objects are stored in a GDMS datasource.

LayerCollection


A set of BasicLayer. A LayerCollection can store different kinds of geographic objects. For example a LayerCollection can group vector features and raster data.


Datasource

A datasource is an heterogeneous collection of spatial or alphanumeric objects :  geometry, raster, integer, double, boolean, date...

Raster


A Raster is an abstraction of the real world where spatial data is expressed as a matrix of cells or pixels. Data are divided into rows and columns, which form a regular grid structure. A Raster can have continuous  discrete values.


Geometry

A Geometry is an heterogeneous collection of  geometries. They may represent buildings, roads, streams. It is made up of a geometry (point, linestring,  polygon, multipoint, multilinestring, multipolygon). 

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