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APPLICATION OF MARINE GEOGRAPHIC INFORMATION SYSTEM 
USING ANALYSIS OF CONTROL POINTS 
IN POST PROCESSING DGPS SURVEYING 
In. Joon. Kang ®*, Sang. Seok. Kim? Yong. Gu. Jang ®, Byung-Gul Lee © 
; “ Dept. of Civil Engineering, Pusan National University, pnu92@pusan.ac.kr 
GIS/LBS Project Center, Korea Institute of Construction Technology, wkddydrn@kict.re kr 
* Dept. of Civil & Environmental Engineering, Cheju National University, leebg@cheju.ac.kr 
Commission VI, WG VI/4 
KEY WORDS : Post Processing, DGPS Surveying, Chi-Square Verification ,GIS, Map, Chart, Digital Map 
ABSTRACT : 
The GPS precise surveying which is prevailing in Korea now grasps the problem that the result of the GPS observed value is used 
without the analysis of the relationship between the geometric strength and the variance factor. And it was accomplished by the 
necessity of the unified projection of Digital Map and Digital Chart for the unified geographic information system construction on 
the land and the sea, respectively. 
The purpose of this study is firstly presenting the method to improve the precision of the observed value in GPS, and secondly the 
direction for the unified management of Digital Map and Digital Chart by comparing and examining the boundary line error that is 
on these maps which used the GPS control point through the unified projection of them. For the former, it was done using the 
precision analysis method that was divided into two parts as the geometric strength and the change of the variance factor in the 
observed value of GPS. And all these are for 3 control points which is used in GPS network adjustment. 
In this study, when we matched the Digital Map to the Digital Chart by using the coordinate of the boundary point through the 
EDM was carried out in using the result of GPS surveying, generally we could know that the errors were happened largely in the 
southeastern direction. 
1. INTRODUCTION 
Theoretically, GPS has the capacity for the mutual positioning 
to a few millimeter and also is possible to survey scores of 
kilometers in a short time without the mutual collimation. So, it 
can get the positioning value in the area which has the existing 
control point to be desired and the difficulty to survey. 
Moreover, it's receiver is easy to be used when compared to a 
existing surveying instrument, and if it is connected with 
computer, the result value is acquired immediately. GPS is 
becoming a very effective surveying means for these reasons. 
Also there are many kinds of GPS receivers to be developed, 
and the cost is lower and lower. These are caused by the 
advance of hardware and the combination the GPS positioning 
function with a computer technology. 
GPS method is classified into the Static method, the 
Kinematic method and Dynamic method. The first is used in the 
precise static surveying, and the second, though this has a poor 
precision, is used in traverse point, boundary surveying, and the 
last is for tracing the real time position, connecting to the 
navigation instrument. 
In the case of the Static surveying for GPS precise geodetic 
surveying, it must be carried out to proportion precise 
coordinates by the GPS network adjustment that use the control 
points as postprocessing. The GPS positioning involves not 
only *natural' errors associated with the satellites position errors, 
refraction of EM wave in the ionosphere, etc. but 
  
also 'artificial errors associated with the operation of S/A. 
Internally, Many of authors have studied on DGPS in order to 
improve the GPS Positioning Accuracy.(Kang, Lee, 1995; Kim, 
1996; Park, 1997) For estimating the precision of GPS survey 
for the long baseline measurement, Yoo, H. performed the 
simultaneous GPS observations at two points in Korea and nine 
points in Japan, and analysed the precision of GPS survey by 
using broadcast ephemeris and precise ephemeris.(Yoo, Pio, 
1997) 
After GPS network adjustment carries out the base analysis, it 
does this adjustment by fixing 1 point, 2 point, or 3 point. 
Generally the method of 3 point fixing is used. (Kang, 1996) 
Externally, they have used GPS for Hydro-Oceanographic 
Surveying(Abidin, 1994). Many of authors have studied and 
read paper about the GPS Networks, GPS Heighting, real time 
differential GPS surveying actively.(Brunner, 1994; Collier, 
Armstrong, Leahy, 1994; Doller, 1994) 
Recently, they applied GPS surveying on wide area and 
studied on Error analysis(David, 2003), Fault Detection and 
Exclusion Using Normalized Solution Separation and Residual 
Monitoring Methods.(Ryan, 2003) 
There are many kinds of domestic digital maps. Widely, these 
are divided into a digital map and a Digital Chart. At present, a 
digital map is turned out by the TM projection method and 
Digital Chart is by the UTM projection method. 
Now, as the process of the united management for the 
national geographic information on land and at sea, the 
geographic information system is constructed on land, and the 
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