6B-1-6 
Thus, it can be concluded that a GPS positioning tech 
nique used in a rolling management system or a con 
struction vehicle monitoring system should be selectable 
according to the environmental conditions under which 
the system is to be used. 
Table. 10 The percentages of 
effective measurements by RTK-GPS 
Samples 
Errors 
Probability 
of Error 
1 
693 
178 
25.685% 
2 
650 
112 
17.231% 
3 
672 
24 
3.571% 
4 
702 
16 
2.279% 
5 
680 
30 
4.412% 
6 
1871 
57 
3.046% 
7. CONCLUDING REMARKS 
The authors developed a construction vehicle monitoring 
system using DGPS and RTK-GPS. The system is still at 
the experimental stage. The test results indicate, however, 
that the system will be highly practicable if the GPS-based 
positioning method to be used can be selected according 
to the environmental conditions. 
The next step is to test the system for practicality and 
field-test and refine it so that high-quality rolling manage 
ment can be performed. 
REFERENCES 
1) Tsuchiya,A., Tsuji.M., 1995. The Basic of GPS 
Surveying, A Corporate Juridical Person. Japan 
Surveying Society, pp. 135-214. 
2) Sada, T.,Takada, T., Hard-hat GPS:Real-time Kinematic 
Surveying on Construction Sites, GPS World, 
1994.11,pp.26-28