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The proceedings turned out sufficiently exact and economically convenient.
While the above mentioned work is referred to practical case, the tests made by
the Swedish Hydrographie Dept. of the National Board of Shipping and Navigation
with flights at 10.000 m altitude are still at the experimental phase of search.
The tests made in order to obtain a net of control points for large and medium
scale cartography for nautical purposes, and the results obtained, are described in the
note « Stereotriangulation with photographs from 10.000 m altitude» in the Interna-
tional Hydrographie Review — November 1958.
The square average value of planimetric errors turned out to be of -- 2 m about.
7. — CONCLUSIONS
To conclude properly the analysis of results obtained from the research on the
technical applications of aerial triangulation, it would be necessary to make a compar-
tive analysis of the present stage of the activity with the one in the previous 4 years
as it results from the Stockholm Congress’ Report.
From the aforesaid analysis it shoud be possible to state the increasing factor that
both aerial triangulation on its whole and the several triangulation proceedings have
recorded in an absolute and relative sense.
However, owing to the different criterions of the enquiry and mostly of the
unregular distribution of replies, 1t 1s deemed impossible to carry out such a research.
Anyway, also the analysis of the productive augmentation only in a limited num-
ber of Countries might be not only of very little meaning, but perhaps also a false one.
We do not think it worthy to deduce anything more from the quite unanimous
concordance of replies to the general part of the questionnaire than a sure increase of
aerial triangulation in the future.
More significant may be a comparison between the conclusions reached in the
Commission III's Report at the Congress held in 1956, and the conclusions that we
can draw from the present situation.
The Secretary of Commission III, in charge in 1956, Mr. Van der Weele concluded
his sharp analysis on the aerial triangulation problem with 8 statements of which we
think useful to control, afterwards, not so much the validity 1n the absolute sense,
where they already fully justify themselves, as in the relative sense: namely, the effec-
tive correspondence with practical developments (1).
(1) The conclusions by Mr. Van der Weele included into the 7th section of Chapter X of the ** Rapport
Général de la. Commission III" **L'Aérotriangulation et son application à la Géodésie" (VIIIe Congrés de la
Société internationale de Photogrammétrie — Stockholm 17 — 26 Juillet 1956), are reported here below:
l^ L'organisation d'une préparation efficace est économiquement avantageuse. Il importe de déchar-
ger l’opérateur-restituteur de toute autre tâche que le travail à l’appareil.
20 La comparaison des méthodes de triangulation aérienne manque encore d’une base objective.
Toute initiative pouvant améliorer cet état de choses doit être encouragée.
39 L'appliestion de la méthode analytiqe de triangulation aérienne postule une amélioration des
stéréocomparateurs existants.
49 Dans le développement des techniques de caleul en photogrammétrie, le problème de la com-
pensation du bloc mérite la priorité.
59 L'emploi d'appareils auxiliaires pour la détermination des inclinaisons de l'axe de la chambre
de prise de vues présente une grande importance pour la compensation du bloc.
69 L'application au bloe photographique d'une méthode de compensation rigoureuse rend superflue
la discussion sur le caractère des discontinuités (sauts et cassures).
7° Le développement des méthodes électroniques de localisation mérite une attention spéciale.
89 La triangulation radiale numérique peut, dans un proche avenir, connaître de nouveaux déve-
loppements.
21
