4-1-7 
consumed about 26 hours of flying time and yielded a 
productivity rate of about 580 powerline spans per hour. 
In addition to the 66 kv high-voltage lines, some 2000 spans of 
lower voltage lines were also recorded, but at the slower rate of 
165 spans/hour. The low-voltage lines required more aircraft 
maneuvering. The selected imagery for stereo analysis filled 14 
CD-ROMs and all extracted powerline survey data was 
subsequently entered into a SMALLWORLD GIS. 
6 CONCLUDING REMARKS 
The airborne RCAMS demonstrates that a relatively 
inexpensive mobile mapping system for powerline recording, 
and specifically for mapping vegetation in support of bushfire 
mitigation, can be configured through an integration of stereo 
video imaging, kinematic GPS and inertial positioning sensors. 
Moreover, utilization of the concept of photogrammetric self 
calibration enables a complete system calibration for imaging 
sensor interior and exterior orientation, which is necessary for 
accurate triangulation and geo-referencing of feature points 
within the recorded video imagery. The RCAMS application to 
66kv powerline mapping described in this paper was carried 
out in 1996. Were the system to be assembled today, it is more 
likely that high-speed digital CCD cameras or digital video 
technology would be employed instead of analog SVHS video, 
and advantage would also be taken of both recent 
developments in kinematic GPS and improvements in attitude 
sensor technology. Otherwise, the proven basic design criteria, 
processing algorithms and operational procedures would 
remain essentially the same. 
7 REFERENCES 
Hunt, J., Rowlands, A. and Judd, A.M., 1998. Rapid Rail 
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Leahy, F.J. and Judd, A.M., 1998. Precision Rapid Route 
Mapping Incorporating Stereo Imagery. Presented paper, 
ISPRS Commission II Symposium “Data Integration: Systems 
and Techniques”, Cambridge, July 13-17, 8 pages. 
Leahy, F,J. and Judd, A.M., 1999. Precision of Models for 
Kinematic Positioning in Rapid Route and Facilities Mapping. 
Proceedings of the International Workshop on Mobile 
Mapping Technology, Bangkok, April 21-23 (this volume).