Sb. Bortolami et al., MODELING THE SYSTEMATIC UNCERTAINTY OF PHOTOGRAMMETRIC TRACKING OF HUMAN MOTION, Journal of dynamic systems, measurement, and control, 119(2), 1997, pp. 358-361
We address bias errors of photogrammetric tracking of four SELSPOT-II(
R) cameras using active marker photogrammetry in a 2 m x 2 m x 2 m vie
wing volume for human locomotion measurements. We present uncertainty
modeling regarding the first stage of equipment set tip, which provide
s the camera frame to global frame rotation matrices and the distances
among cameras. We also characterize the uncertainty due to the camera
distortions of the bare system as compared to published performances
achieved with a camera correction procedure. The particular approach i
s to qualify performances of photogrammetric tracking during routine o
peration and to identify the nature and magnitude of the uncertainty d
ue to equipment set tip and camera distortions as part of the total un
certainty in a self-consistent manner. We found that uncertainty of th
e camera frame to global frame rotation matrices produced rotation of
the image and uncorrected camera hardware uncertainty produced dilatat
ion or compression of the image twice the magnitude of that seen with
camera correction. However, camera resolution remains as an equally im
portant factor limiting the accuracy of photogrammetric tracking that
can not be easily reduced numerically. In conclusion, the analysis elu
cidates how uncertainty propagates to numerical derivatives of the tra
cking data and prepares the groundwork for future development.