/e targets per 
circle. 
  
ing object 
  
=m 
) control points 
otation arm 
^ cameras 
396 
  
  
Number of Circularity Out of plane 
points per track (um) (pm) 
guum 30 30 
9 25 30 
9 26 40 
9 28 25 
16 29 31 
16 27 31 
16 27 38 
16 28 28 
18 28 36 
16 28 37 
16 28 37 
16 27 32 
146 29 39 
  
  
  
  
Table4 Measurement results 
Deviations from circularity and out-of-plane measures 
are given in Tab. 4. The repeatability of the results 
shows that the measurement is nearly independent of 
the number of points per track. The rms deviations from 
the circularity are between 25 and 30 ym and the 
deviations from the best fit plane are between 25 and 
40 um. 
4. OFF-LINE MEASUREMENT WITH KODAK 
DCS 460 CAMERAS 
If an object is signalized with a number of tiny lamps or 
LED's, continuous light traces can be observed during 
object motion and recorded in a single image taken by a 
camera with open shutter. Pulsed light sources create 
light points or streaks at regular intervals. This 
measurement technique has been applied successfully 
using photographic cameras (Dorrer and Peipe, 1987; 
  
Figure 5 Digital motographic image 
473 
Güthner and Peipe, 1988). Now Kodak DCS 460 high 
resolution (3000 x 2000 pixel) digital cameras which 
can be operated like photographic small format 
cameras are used to acquire such motographic images. 
If a moving object is signalized with retroreflective 
targets, a similar single image technique can be 
applied. A flashlight illuminates the targets several 
times and the imaged light points represent the object 
motion. 
Both methods were tested using the rotating bar as 
moving object. One active or passive target was 
attached to the bar. The circular light traces were 
recorded by two DCS 460 cameras (Fig. 5). As result of 
the image measurement and object reconstruction, 3-D 
coordinates of the light points or streaks were 
determined with an accuracy of about 100 - 150 um. 
Further investigations are necessary to improve the 
recording techniques and the accuracy of motion 
estimation. 
  
Encoder 
Retroreflector 
  
  
  
  
Figure 6 SMART Laser Tracker 
5. ON-LINE 3-D COORDINATE MEASUREMENT 
WITH THE SMART LASER TRACKER 
The SMART 310 Laser Tracker (Fig. 6) is a 3-D 
metrology system that uses a single beam laser 
interferometer to measure the distance and two angle 
encoders to measure the horizontal and vertical angles 
between the measuring head and a reflector 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996