199 
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