International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004 
2. CASE STUDY 
2.1 Structure and Tools 
In this study, mapping application type is dynamic web 
browser. Dynamic maps enable to choose features that will be 
displayed, such as the scale, location etc. 
applications, maps are drawn according to preset parameters. 
And then the web browser displays the map as an image. By 
changing the parameters, users can generate and view a new 
map. This type causes heavy load on the server side. The server 
side has geographic data, GIS softwares, and an interface 
program (Figure 2). It requires also programming to provide a 
map service. In this study, activex control is used to extend the 
browser capabilities. When users visit the site, the control is 
downloaded automatically and temporarily. 
m. asie + parameters 
NTER a 
EN 
map 
  
GIS 
Software 
    
     
GIS 
Interface PEE 
Program 
Application 
Development 
Environment 
  
Figure2: Server side model 
MapObjects ActiveX software component and MapObjects 
Internet Map Server (MOIMS) software are used in the study. 
MapObjects is used to build the GIS application and MOIMS is 
used as a gateway program. MapObjects and MOIMS are used 
together with Visual Basic application development 
environment. Windows XP is choosed as the operating system 
and Microsoft Internet Information Server (IIS) is it's web 
server. It is used to share information over the Internet. Also 
Microsoft Internet Transfer Control is used to connect other 
web servers and retrieve HTML documents for the application. 
In order to listen requests from the users, WebLink ActiveX 
Control is used. For the preparation of the spatial data ArcView, 
ArcInfo, Erdas Imagine, and Microsoft Photo Editor programs 
were used (Figure 3). 
  
  
  
(MicroSoft Windows XP) 
Application Development Environment 
Web Server (MicroSoft Visual Basic) 
(MicroSoft IIS) 
Application Development Tool 
(ESRI MapObjects ) 
Map Server Data Compilation 
: v mmpiau 
(ESRI MapObjects IMS) (ESRI ArcInfo, ArcView, 
ERDAS Imagine, MS Photo Editor ) 
  
Figure 3: Tools 
2.2 Data Acquisiton and Manipulation 
Entire Turkey is the study area. Both raster and vector 
geographic data types are used in the study. Raster data 
represent topography and population density. Vector data 
In this type of 
146 
represent current earthquakes, historical ^ earthquakes, 
earthquake record stations, fault lines, GPS stations, 
displacements by GPS, city boundaries, city centers, county 
boundaries, map index, lakes, rivers, and roads. GIS data come 
from different sources and in a variety of formats. For 
combining multiple files on the same display, data must be in 
the same spatial reference system. Figure 4 displays data from 
different sources in different datums and forms. 
  
  
Dias Chat of us World 
USGS GTOPO30 Project 
Com | http; //edcaaec 
scale: 1/1,000,000 projection: geographic 
format: shp (esri Cities : 
fi p (esri) | Counties datum: wgs-84 ___ DEM 
projection: geographic — City Centers || unit: decimal degree 
; Roads | 
datum: wgs-84 Lakes z-unit: meter 
unit: decimal degree Rivers 
  
ellipsoid: wgs-84 
  
  
Kandilli Observatory and Earthquake Research Institute 
(Bodazigi University-Turkey) http://www.koeri.boun.ed 
Current Earthquakes 
Historical Earthquakes 
Earthquake Record Stations 
Fault Lines 
projection: geographic 
datum: ed-50 
unit: dms 
projection: geographic 
datum: wgs-84 
unit: dms 
GPS Stations 
Displacements by GPS 
} 
Figure 4: Data, sources, and formats 
  
  
  
  
  
Digital Elevation Model were exported to cell based grid 
format. ArcView was used to classify grid data according to its 
height values. In order to use raster data in MapObjects Internet 
Map Server application, data were converted from grid format 
to JPEG image format. And then it was converted to TIFF 
format using Microsoft Photo Editor software. Because 
MapObjects displays TIFF format more efficiently than JPEG 
format. For population density map, ArcView and it’s scripting 
language were used to calculate areas of the boundary polygons 
and colorize shape file according to the population density 
values. Population values of districts were added to districts 
dBASE table. Density image was exported to JPEG format. 
And then JPEG file was converted to TIFF format. Current 
Eartquakes and Historical Earthquakes layers were symbolized 
using their magnitude and depth values. Other vector layers 
were symbolized with single values. 
In the study, vector data format is ArcView shape file format. 
Vector data downloaded from http:/www.gisdatadepot.com 
DCW web site were acquired in shape file format. For other 
ASCII text files which include coordinate information of 
stations and earthquake parameters information, ArcView 
scripting was used to convert text file to shape file format. 
All of these data were in geographic coordinates relative to the 
WGS-84 and ED-50 datums. Datum transformations and 
coordinate conversions were performed. Data were projected to 
Lambert Conformal Conic map projection. It is one of the best 
for middle latitudes. ArcView can not export maps to 
georeferenced images. So topographic map image and 
population density map image were georeferenced to the 
Lambert Conformal Conic projection by using image 
processing software ERDAS Imagine.