auig-
| des-
Fest-
'ering,
Photo-
; 1948.
' Bild.
9
Communication to
VIII International Congress for Photogrammetry
Reprint from
Svensk Lantmateritidskrift
Congress Number 1956
Commission 11
THE INFLUENCE OF RADIAL DISTORTION AND OTHER
SYSTEMATIC ERRORS UPON PHOTOGRAMMETRIC
MODELS FROM APPROXIMATELY VERTICAL
PICTURES
By B. Hallert, Stockholm 70, Sweden
Introduction
If radial distortion is present in the aerial pictures and the distortion
is not compensated in the plotting instrument, deformations of the pho-
togrammetric model will occur, that may cause considerable systematic
errors of particularly the elevations and also of the x- and y-coordinates
of the model,
Concerning the elevations, two different types of deformations have
to be distinguished, namely:
1. Deformations due to the direct influence of the distortion upon the
x- (horisontal-) parallaxes of the model.
2. Deformations due to the indirect influence upon the x-parallaxes
of the model via the y-parallaxes in the orientation points.
The first (direct) type of deformations has frequently been treated
in the photogrammetric literature, see for instanse Bean [1] or Tham
[2], but the latter (indirect) one seems to have been more or less
neglected. Schwidefsky [7], briefly mentions this effect, however. In
this paper a brief demonstration will be made of how the model will
be deformed due to the systematic errors of the relative orientation as
caused by the influence of the radial distortion upon the y-parallaxes.
We will start with the treatment of the influence of the radial distor-
tion upon the elevations.
As is immediately clear, the radial distortion will cause varying y-
parallaxes in the model in addition to those, caused by other circum-
stances, for instance lacking reconstruction of the relative orientation.
See for instance [2]. For the derivation of the actual formulas we will
temporarily assume that the relative orientation is exactly reconstructed