Characteristics of Data in GIS

Characteristics of Data in GIS:

1. Location:

ü  Spatial locations are defined by co-ordinates in specific reference system.

ü  Represented by Lines, points and polygons.

2. Temporality:

ü  DB model should consider both existence and change over time of features.

ü  Especially crucial with dynamic data.

ü  We are in need to represent current valid data

3. Complex spatial Features:

ü  Several representations includes points, lines, polygons and raster

4. Thematic values:

ü  Different properties and qualities of objects are represented as attributes.

5. Generalization:

ü  Relates to the level of scale and details associated with objects.

ü  Aggregation of objects is from lower to higher scale.

6. Roles:

ü  Objects are assumed with different roles according to the universe of closure.

ü  Usually application dependent.

7. Object ID:

ü  Objects should uniquely identified within data model.

ü  It is necessary for data exchange purpose.

8. Data Quality:

ü  Refers to credibility and accuracy of data.

ü  2types of Quality:

o   Quantitative-relates to measurable components such as spatial accuracy.

o   Qualitative- non measured components that are not to specific objects