Table.4 Accuracy of Measurement 5) A level of accuracy adequate for practical purpo-
Measuring area 40m X 40m se can be obtained by the three-dimensional shape m-
easurement using digital still cameras, making great
Tota ion 2 : 12.3 » contributions to raising the efficiency in the mea-
mesh 10m 20m h = 14.9 m surement work at construction sites
a mesh length : x m= == 10 5
on matching(m) : y SES EZ 10 5
BS errorof i xf —- + —| 0213 0.218
standard point ' y === —— 1 0.608:0.688 REFERENCES
(m) 12}. 70 2772), 9.110. 9.120
RMS error of hight e === 0.208 0.257 1)Application of GPS Navigation Sensors to Position-
volume of cutting | 0.000 165.52 | -20. 531 -75.65 ing of Heavy Earthwork Equipment, Proc. of the 46th
(n3) 0% 15.3% 1.92 1.0% Annual Conference of the Japan Society of Civil Eng-
volume of 0.000 71.367 | 18.128 -111. 59 ineers, Sept. 1991, pp.324-325 (in Japanese), Sakurai
embankment (m?) 0% 7. 8X 2.0% 12.3% AK. Nakagawa, Y.. Takads, T. & Sada, T.
error of volume 0.000 250.90 | 21.028 -24. 738
2)A Study on the Applicability of GPS to Engineering
3 ; ; ; Work, 8th Symposium on Issues Relating to Construc-
Table.5 investigation of surveying efficiency ; ;
tion Management, Dec. 1990, pp. 225-232 (in Japanese
. ), Nakagawa, Y., Takada, T. & Sada, T.
Time (min) measurment : analysis
by sut i 20 3)GPS-A Precise Geodetic System using Artificial Sa-
Weasurment Dy, sti camera tellites, Japan Association of Surveyors, 1986 (in
: Japanese), Geodesic Society of Japan
measurment of Range Finder 54 |! half day
5 CONCLUSION
The results of the research and development work
for the system may be summarised as follows.
1) The system curtails the time and personnel requi-
red for conducting patrols for safety control and o-
ther purposes on construction sites,while the patrol
results, which can be reproduced instantaneously at
the site office, can be used immediately for consu-
ltations and giving instructions.
2) Since the patrol positions are recorded automati-
Camera cally using GPS in the site information collection
system, there is no need for confirmation of the po-
sitions using markers and other devices. This means
that those conducting the patrols need not be famil-
iar with the site and that even on sites where the
landscape is changing constantly those conducting t-
he patrols can confirm their positions on maps and
are not likely to be misled.
3) On the site office monitoring system, the inform-
ation can easily be displayed on maps on the CRT ,
facilitating explanation to newcomers and visitors
unfamiliar with the site.
4) The instant display of the site conditions using
electronic still cameras facilitates consultations
and giving of instructions.
41