2.2
ant
rcm-
3.5
o. e
Je
errors in the photograms were chosen to be d = 100 um to
allow an easy conversion of the results to other magnitudes
of deformation.
THE EFFECTS OF SYSTEMATIC IMAGE ERRORS IN THE PROCESS OF
AERIAL TRIANGULATION
The Synthetic data:
What now are the effects of the selected basic types of image
deformation in the process of aerial triangulation? This
question was answered by Kubik (1971) and Clerici (1972),who
studied synthetic strips and blocks of wide angle photography
up to a blocksize of 9 strips each with 18 models. The terrain
covered by the blocks was assumed to be horizontal.
The error magnitudes:
After the various stages of aerial triangulation - model- and
stripformation, stripadjustment, blockadjustment - grid
coordinates of the minor control points were obtained, The
differences(e,, e, e,) between these and the true coordinates
were computed and plotted for all points in the block. Further-
more the maximum coordinate errors, e and the standard
max?
deviation o of the coordinate errors in a block were derived
(separately for each coordinate direction) according to the
formulae: e = max fe
max + À
0 {5 e dua
Ni i
where i stands for the point number, ranging from 1 to the
total number. of points, N, in the block. in order to eliminate
the influence of the photoscale in the results, all values
are expressed in units of 1| um at the photoscale.
Error effects after model- and stripformation:
The photogrammetric strips were computed using the cantilever
strip triangulation method of van den Hout (1966). Other
methods of strip formation have not yet been investigated
so far. The deformations of the individual models and of the