ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001
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newer than t2. Then, execute the GDSF commands stored in The system definition file define the extent of the spatial data
the queue in the working memory W while the time print of the and names of several definition files,
command is newer than t1. When the steps have completed,
the entities existing in W are a part of the result. To do this Spatial index file is for high-speed spatial retrieval, which is
operation over the leaf nodes overlapping the specified area, organized by GBD-tree. The contents of vector file and
the change can be detected in the area. connector file are managed by this index.
5. DATA FORMAT Legend definition file defines several attributes of depicted line
Figure 7 shows datasets used in STIMS. The detail of the format and regions, including the kind of hatching, kind of line,
will be released to public after fixed the detail of the format. thickness and color.
system definition file
F'S 7 Organization of STIMS files
Theme definition file define several kinds of theme used in
several kinds of spatial retrieval. A theme is defined by a
ordered set of line kinds. For example, city shape is defined the
region divided by shoreline, country border, prefectural border,
city border, and sheet border. The theme definition file defines
such kinds of line for each theme.
Differential script file is for synchronization with external GIS.
This file is similar with transaction file, recording addition and
deletion of geographic entities.
Current version of STIMS has simple DBMS to manage
attribute information. The attribute database file showing in the
figure is this file. For more complicated query, ordinary database
managenet system, for example SQL server, MS ACCESS, or
Postgre SQL, are used. To connect these attribute databases,
STIMS provides two interfaces. The first one is attribute
database interface file, and the other one is communication
using ODBC. Suppose an order to color each city area to
distinguish the population density according to a legend, the
send to external attribute DBMS. Then the DBMS replay the
result by an attribute database interface file.
6. CONCLUSION
STIMS is now implemented on PC by VC++. At present, basic
spatio-temporal data and attribute data handling is available.
Figure 7 shows an example of STIMS window.
This paper describes abstract feature of spatio-temporal
geographic information system based on Implicit topology
description. This system will be open to public as free software
in near future.
At present, core of spatio-temporal management has been
implemented, however, ample functions for spatial calculations
and operations have not been implemented yet. According to
user’s feedback, to enrich such functions are future issues.
The implicit topology description model adopted in STIMS
require much calculation time than conventional GIS. this
problem becomes less serious according to remarkable
progress of computer power. However, when several users
access the system through network simultaneously, the
calculation load may become large. The authors have been
developping a chase method to settle the problem. To adopt the
method to STIMS is a future work.
