1easure-
e image
ulations
n of the
distance
3. Since
of the
:d in the
ed from
ge coor-
ot mag-
cameras
ms were
e of the
nents in
se Table
ge coor-
e 150
rding to
e film 1s
used. A
r of the
espectiv-
sponding
ind to be
additio-
1 photo-
eometric
with the
tographs
ipon the
perature
tographs
)hs taken
method.
ilter was
nnection
cameras
ig power
6.7 For tests of the geometry of oblique photographs a perspective
grid was constructed and the corresponding equation solutions were
performed. The practical tests were satisfactory.
6.8 The results of the tests of photographs from aerial cameras in
a high tower and from the air have clearly indicated that many basic
geometric problems of the fundamental operation number one of aerial
photogrammetry, the photographic procedure, can be successfully treat-
ed in this way, in some cases only in this way. It 1s desirable to continue
the investigations.
6.9 The reliability of the estimation of accuracy can be found from
confidence intervals according to well known statistical methods. If the
adjustment is performed in 5 points the number of redundant measure-
ments 1s 4. For a confidence level of 5 per cent the confidence limits
are found to be 0.60 s, and 2.90 s, respectively. For 2 per cent confid-
ence level the corresponding limits are 0.55 s, and 3.65 s . After ad-
justment in 9 points the number of redundant measurements is 12. For
the confidence level 5 per cent the corresponding confidence limits are
0.71 s, and 1.66 s . For the confidence level 2 per cent the correspond-
ing confidence limits are 0.67 s, and 184 s.
Acknowledgements
[In the experiments the following persons have taken part: From The
Geographical Survey Office: M. Forsell, T. v. Wachenfeldt, K. B.
Segemark, K. Thulin, H. Krosse. From The Board of Land Survey:
C. O. Ternryd, L. Ljunggren. From The Division of Photogrammetry
at the R. Institute of Technology: B. Hallert, L, Ottoson, E. Sigmark,
5. 5j00, B. Shmutter.
The measurements in the photographs and the computations have
been performed at the Division of Photogrammetry.
Financial Support has been given by The Swedish Technical Rese-
arch Council.
7. Application of the grid method for investigations of terrestrial
photographs of various kinds
The grid method has successfully been applied to investigations of
photographs from a great number of terrestrial cameras, microscopes,
and X-ray instruments.
A. few examples of the results of the test of microscopes will here be
demonstrated.
The tests have been performed with the aid of small grids which were
photographed through the microscope in the usual way and also with
grids which were located in the camera and projected backwards
through the microscope. In the latter case the image was photographed
57