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The 3rd ISPRS Workshop on Dynamic and Multi-Dimensional GIS & the 10th Annual Conference of CPGIS on Geoinformatics
Chen, Jun

ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS”, Bangkok, May 23-25, 2001
Linyuan XIA
National Laboratory for Information Engineering in Survey, Mapping and Remote Sensing,
Wuhan University, 129#Luoyu Rd.,430079 Wuhan, China
Tel: 86-27-87881292, fax:86-27-87863229,e-mail: Inyx@hp01 .wtusm.edu.cn, Iyxia@hpb1.wtusm.edu.cn
Jingnan LIU
President office, Wuhan University, 129#Luoyu Rd.,430079 Wuhan, China
Tel: 86-27-87884841, fax: 86-27-87863229, e-mail: jnliu@wtusm.edu.cn
A multi-purpose path representation and optimization system is introduced in this paper. Path analysis can be performed in two
ways:(1)design and comparasion on digital elevation map(DEM)(for initial planning). (2)path evaluation and optimization with GPS
navigation aiding(for practical assessment). Digital model can be generated as DEM by Open Graphical Library with standardARC INFO
data format or with other data format transferred. When implemented with practical GPS navigation data, environmental influence such
as multipath interference can be given and point data quality plus reliability can be denoted on the map. Moreover, if a path is selected by
mouse on the map, possible navigation accuracy by GPS is also indicated for path planning reference. The system can be used for fine
farming, vehicle highway profiling, aircraft forestation and field investigation.
With the rapid development of geoinformatics and spatial
technologies, revolutionary innovations for geography and its
related subjects have occurred. Geoinformatics based
application such as resource management, environment
conservation, traffic control and management, surveying and
mapping is becoming more and more popular and important, and
is gaining daily progresses. One of these development trends is
the integration of spatial technologies(RS,GIS and GPS ). In the
integration application, GIS is the base for comprehensive
application and analysis. Deren Li has developed 3S integration
system of ITS(Deren Li,2000), GPS combined with other
sensors is employed as road network generation(Deren
Li, 1999) . David Tyler used GPS as data collecting sensor to
form DTM for an agricultural GIS( David Tyler,1992). American
Institute of Navigation(ION) designed a AIRPLAN system to
carry out flight routine planning with the global DTM base. In
these application, DTM or DEM data source can be from RS,
digital input or satellite image and it may be global or regional
coverage according to the application purpose of the geomatics
system. The digital mode(DTM or DEM) is an important
component in the database of GIS and forms a basis of terrain
data and topographic analysis.
In thsis paper, a DEM is employed as a means of an area terrain
representation to depict the earth’s relief, GPS receiver Is
equipped into a dynamic object(vehicle or low flight plane) to
collect data and achieve navigation. The positioning data is
post-processed(differentiated if necessary) to get point position.
Flight path or traveling path is then denoted on the DEM. Open
GL approach is used to form moving terrain along the path to
show the dynamic geographic environment. As an option, the
terrain induced multipath influence on navigation and satellite
distribution on the sky is indicated on the dynamic terrain map.
Zooming local comparasion and optimization can be carried out
in the software system.
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Figure 1. Start Up Of The Software
In this analysis system, spatial modeling of the regional terrain is
described by DEM. Source data is archived in format of standard
ARC/INFO. To achieve the display of DEM and the related
analysis, the source data is extracted and decoded firstly, and
then data points are synthesized by the principle of efficiency
and accuracy, efficiency is mainly the computation speed and
accuracy is the display equality and modeling fitness(source
data equality is not discussed here). In this process, a proper
number of important points are selected and filtered to form
some intermediate layer files for later display and analysis. This
can reduce the burden of too dense points and large data
quantity. The general chart is as follow.