112 PRESENTATION OF THE GENERAL REPORT OF SUB-COMM Iv-l
tion of the research work; I think they are of
importance. We have the impression from our
work that up to now the importance of the
procedure in the autographs has been over-
estimated. It seems to be of far greater impor-
tance for us to concentrate upon earlier stages
of the photogrammetric process, for example,
the changes of dimension of the photographic
material, the signalisation and we mean the size,
form and contrast to the surrounding ground,
the identification of the points in the model and
several other questions, if you want to extend
the accuracy of the measurements.
Further, we have had the most excellent
co-operation with Mr Härry and his colleagues
in Switzerland, as a matter of fact, without his
valuable support it would not have been possible
to make any research at all. Nevertheless, we
recommend that for the future the test field
should be localized to the same country that is
responsible for the error investigation and the
statistical treatment of the observations.
For the continuing researches within Com-
mission IV-1, it is of course necessary to dispose
a test field with a very accurate geodetic net-
Work. A test field is a very expensive establish-
ment and can serve many purposes in combina-
tion. It is also an advantage, in our opinion, to
give it a permanent character, a place where
you can repeat tests continuously and under
identical conditions. For the special purposes of
Commission IV-1 it ought to combine the
character of Oberriet and Monti di Revdira,
thus including both flat and hilly terrain, and it
should be as varied and diversified as possible.
No doubt it would be valuable if a test could
include larger material of measured points than
Monti di Revoira. A statistical treatment of this
material would probably give more valuable
results.
Let me recommend once more that we
recommend every test in the future should be
combined with a special investigation about the
cause of gross errors and a study of the possi-
bilities of eliminating them.