ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS’’, Bangkok, May 23-25, 2001
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A SPATIAL-TEMPORAL DATA MODEL FOR MOVING AREA PHENOMENA*
Shanzhen Yl\ Yong ZHONG 1 , Lizhu ZHOU 1 , Jun CHEN 2 , Qilun LIU 1
1 Department of computer technology and science
Tsinghua University, 100084, Beijing, China
Tel: 86-10-62789150
E-mail: ysz@mail.tsinqhua.edu.cn
dcszlz@mail.tsinghua edu.cn
2 National Center of Geographic Information of China, Beijing, China
Tel: 86-10-68424072
Email:jchen@gps. ceic.gov.cn
KEY WORDS: spatial-temporal data model, moving phenomena, GIS, database.
ABSTRACT
The spatial-temporal data model of moving object is a critical problem for spatial-temporal database, geographical information system,
and multi-media information system. In this paper we give a spatial-temporal data model for moving area phenomena, named OPH
model. In this model, the feature geometry of moving area object described by three sub-geometries, which are observation geometry
of the moving area object, named O; currently present geometry of the moving area object, named P; and history geometry of the
moving area object, named H. We give the definition of OPH, and than using the union, intersection, and difference of set theory to
populate and update the value of OPH. We define the spatial-temporal topological relation between moving area object, then we give
the spatial temporal operators and define trigger on OPH.
*This research is supported by Natural Science Foundation of P.R.China (Number: 69833010).
1. Introduction
The researches of spatial-temporal data model include
spatial geometry representation of variational spatial objects
over time, spatial-temporal topological relation, and
operation on them. In geographical information system
(GIS), spatial phenomena (or object) usually be represented
as vector graphics, such as point, line and polygon. The
vector model can describe spatial distribution of spatial
object, but could not represent evolvement for spatial object
over time. The information of spatial distribution and
temporal evolvement of spatial object is useful for many
fields, such as moving point object of vehicle, ship, and
aeroplane, moving area object of land use, weather, urban
growth, and area pollution. Currently the observation of
remote sensing provides huge different temporal location
data of spatial object. In order to apply different spatial and
temporal data to resolve the problem of interaction between
spatial processes, to reply the spatial-temporal query, we
need to research and develop spatial-temporal data model
for spatial database. This paper contributes to the research
of spatial-temporal data model of moving area object.
There are many separate researches about spatial database
and temporal database, these researches did not effectively
combine spatial aspect and temporal aspect [Andrew Frank,
1999. ]. The literatures for dynamic spatial object include
David J.Wilcox 's Modeling Dynamic Polygon Objects
[ David J.Wilcox, 2000 ] which models dynamic polygon
object, gives Spatial Temporal Graph Model (STGM) and its
data structure. In the graph the node represents polygon,
direction edge represents relation of polygon evolvement. In
temporal aspect, this model only represents the change of
whole polygon, does not represent the growth, surviving,
and disappearance of polygon object, can not reply
spatial-temporal query.
Donna J. Peuqeut gave an event-based spatio-temporal
data model ( ESTDM) [ Donna J. Peuqeut 1995]. In this
model the changed section of area object at an instant is
regarded as an event, a series of changed sections of the
object at different instants regarded as a list of events
which recorded the changed value of object. The changed
value is recorded by run-length-encoding. This model is
based on raster model.
Kathleen Hornsby and Max J, Egenhofer gave the concept
of identity-based change [ Kathleen Hornsby 2000].They
Introduced existence object, non-existing object without
history and non-existing object with history, and brought
forward continue existence object, new created object,
recalled object, destroyed object, etc. but they do not give
the data model and data structure.
In this paper we consider area moving object (MO) in
2-dimension plan Euclid space, discuss dynamic change
and history of the object, and give spatial-temporal data
representation, spatial-temporal topological relation, and
several operators.
2. The OPH model of area moving object
Area objects in 2-dimension space are represented as
geometry polygon or geometry function in spatial database.
We usually use polygon representing spatial irregular area
object, and use geometry function (such as rectangle, circle,
etc.) representing regular area object. We name all of them
as spatial geometry.
We give the OPH model for area moving object. Where
geometry O represents the observation geometry snapshot
of area object at an instant, geometry P represents the
sections of object which generated at past instant and
continue existing at current instant, and geometry H
represent the sections of object which existed during past
period but did not existing at current instant.
2.1 Spatial and temporal representation of area object
