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V.P. Nenonen and Y. VaiscllH of Finland developed in 1936 a method
of aerotriangulation aided by horizon photographic records and statoscope
readings. This initiated the concept of using auxiliary data for photo-
triangulation.
Bertil Hallert (1910-1971) a professor of the Swedish Royal Techni
cal Institute at Stockholm contributed much in developing numerical rela
tive orientation procedures and establishing the concepts of calibration,
and standards for testing cameras, comparators and stereoinstruments. The
terra "standard error of unit weight" was first used by him.
Starting in the early 1930s through the 1950s, some theoretical
and conceptual analytical developments were made at the Federal Institute
of Technology, Zurich by Professor Max Zeller and his associates, some of
whom continued their contributions well into the 1970s. Arthur J.
Brandenberger and W.K. Bachmann, two outstanding ones of the group made
numerous contributions in various orientation concepts. Hugo Kasper, also
of Zurich, Switzerland contributed considerably to the general concepts
during the 1940s and later.
Earl Church (1890-1956) published a series of 19 articles on com
putational photogrammetrv in the 1930s after the first American Institute
of Photogrammetrv was established in 1929 under his direction at Syracuse
University. The first six articles were bound in a book (Church 1934).
Church started a trend in which numerous scientists made significant con
tributions in the USA for solving problems of space resection, orientation,
intersection, etc. One of the approaches developed by Church, on the
determination of the camera station (perspective center) coordinates by
utilizing an approximate position and an iterative approach, has in effect
remained virtually unchanged to this day. He, however, separated the
solution for the orientation angles from the camera station coordinates.
He also tackled another problem which he called "Determination of scale
data" i.e. to compute the dimensions of objects from the photographs with
out reference to their absolute positions in space. He also turned his
attention to the calculations of rectifier settings. He later formalized
his procedures by codifying his derivations in the direction cosine nota
tions (Church 1948). The approaches of Church were, however, explicit
i.e., with no consideration of redundant observations or data. Also, he
never applied any error analysis to his solutions.
6.2.3 Post World War II Developments
Real advancements were made with regard to analytical methods only
after World War II, although it is recorded (ISP Archives, 1948 and 1952
Congresses) that numerous "experts" would define photogrammetry as the
"art of avoiding calculations". Many of them felt that analog plotting
machines had achieved sufficient accuracy with regard to detail plotting
and contouring. The only area where further developments were required
was aerotriangulation, in which supplementary computational work was always
necessary. In this regard, governmental and commercial interests with
academic collaboration were successful in establishing steady growths in
various aspects in numerous countries. Although these were peace-time
efforts, international competitions, national priorities (in planning and
