^ic
13,
a-
ned
is
1,4 in height, Because of the limited accuracy of the contro]
points and check points, by which the accuracy figures y are
distorted the more, the smaller they are, the real accuracy
advantage of bundle block adjustment can even be expected as
higher,
- Table 4 -
Altogether the test results demonstrate, that by simultaneous
self calibration excellent accuracies can be obtained, even if
systematic errors of considerable size are existing. As an
example we cite the RMS values ux,y obtained with the extreme
control distributions i. = 8 and.i.-= 11. Here, both adjustment
methods lead to amounts of 7 um to 8 um at the photo scale or
20 cm to 22 cm in the terrain. If we compare these accuracies
with the control spacings of 20 km to 31 km we obtain ratios
which are better than 1:105,
Finally, the important statement can be made, that the test
results, obtained with simultaneous self calibration meet the
theoretical expectations in a twofold way. Firstly the standard
deviations of unit weight co, oop and coop are practically inde-
pendent of the control distribution and secondly the empirical
ratios wog, representing the error propagation with the block
adjustment, are in well agreement with the corresponding theo-
retical predictions, being based on random errors only. These
facts indicate,that the systematic deformations of the image and
model coordinates are extensively compensated and that the re-
maining errors can be considered as random.
5. CONCLUDING REMARKS
This reduction of the data errors to the purely random component
is the most important result of the test. It confirms, that the
used strategy for self calibrating block adjustment is fully
effective in the present case, For a real] conclusive valuation
of the suggested Strategy however, further and more generally
drafted tests with block variable systematic errors and diffe-
rent overlap configurations still have to be performed.
APPENDIX
Self calibrating block adjustment with additional parameters,
treated as a collocation problem.
Let us first formulate the functional model of block adjustment
as:
Ax - f = 0 2 (2)
f is the observation vector, containing the measured image or
model coordinates and x is the vector of the unknown terrain
coordinates and transformation parameters. By X an f the theo-
retical values of x and f are ment.
The mathematical model of collocation supposes, that the actual
observation vector f differs from the theoretical one f due to
two random vectors n and s with the statistical expectations
zero (see Moritz |16]).