282 
  
  
Non-Prism Laser-Renger 
  
) Direction of Movement 
  
(ride ^ v Ri S 
    
  
  
  
  
  
  
go E Potted Plant $ 
EN Tes wi = (DHeight 0. 9m 2 
and ee @lHeight 1. 35m u 
—— D Ground @Height 0. 9m N 
Yater @Height 1. Om n (Sections) 
Figure 3. The Conditions Below The Bridge Figure 4. The Cross-Sectional Profile Below The Bridge 
3. Aerial Tests and Results 
We carried out laboratory and fields tests as mentioned in 2. to determine the 
characteristics of the non-prism laser-ranger we would use as a sensor. Ve then mounted this 
equipment onto a helicopter for the next stage and carried out tests to determine if a line 
profile of the ground could be obtained from the air. Before carrying out the tests, we 
investigated such aspects as electricity, oscillation, maintenance equipment, cables, wiring 
and noise, etc., and installed what was necessary. After carrying out various tests, we 
implemented aerial experiments with the equipment configuration indicated in fig.5. We used 
the video camera in the illustration to verify position for the objects being measured. 
The helicopter flew at a fixed speed and altitude, and the non-prism laser-ranger used as a 
sensor measured the distance between the helicopter and the ground continually at a 
frequency rate of 3.3 times per second. The ground surface line profile obtained with the 
aerial tests is indicated in fig. 6. 
Video Image 
Cmposition 
Gyro Frame | 
Video Camera ||: TT D 
Non-Prism d] ) | : 
Laser-Renger d + en 
Super Imposing Boad a Ley 
| + Composit Image 
m 
= 
MM. 
  
  
  
    
  
  
  
  
  
  
  
  
> 
CAE 
EN 
4 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Personal Computer 
  
  
  
  
Expansion Unit 
  
  
  
> 
: Measurement 
Time 
Values 
Figure 5. The Equipment Configuration 
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop “From Pixels to Sequences”, Zurich, March 22-24 1995