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
