Monday, November 24, 2014

Conceptual Data model for GIS

The well known models for storing Geo data are:
             1. Raster Data model:
ü  Raster data- an array of Cells.
ü  Each cell value represents an attribute.
ü  Meta data stored in File header includes cell size, the number of rows and columns.
ü  Manly used for Analytical applications like modeling, map algebra and clustering..

            2. Vector Data model:
ü  Representation of discrete object as points, lines and polygons.
ü  Spatial analyses are done using this model for decision making.

3. Network Model:
ü  Special type of topological feature model.
ü  Allows modeling of flow and transport of resources and services.
ü  Defines how lines are connected to each other.
ü  The rules are stored in Connectivity table.
ü  Everyday application uses this model usually.

4. TIN Data model:
ü  Triangulated Irregular Network -TIN
ü  Mainly used to create and represent Surfaces.
ü  Surfaces are represented as non-overlapping triangles constructed from irregularly spaced points.

ü  Easy calculation of elevation, slope and line-of –sight between points

No comments:

Post a Comment