05 
therefore, 
be trian- 
has used the instrumental measurements for the preparation of his dissertation on 
block triangulation. Miss M. W. Hindman, Research Associate, and Mr. Simha 
Weissman, Technical Assistant, assisted in analyzing the results, and Mrs. Vera 
N. Hoff prepared the final report. 
► E 
2 — MEASURING INSTRUMENTS AND MEASURING PROCEEDINGS 
1. Instrumental Work. 
First, the three principal strips (tie strips) T-1, T-2, and T-3 were triangulated. 
The longitudinal strips (filler strips) 1, 2, 3, 4, 5, 6, 7, and 8 were triangulated on the 
basis of points obtained from the unadjusted principal strip triangulations. The 
instrumental work was done, basically, according to the aerolevelling method described 
in Publication [1]. 
Predetermined 6z-values from the statoscope data were introduced into the A7 
and the relative orientation was performed by elements by' or by", co 7 or u>", cp' 
and cp", yJ or y." according to the optical-mechanical procedure (tolerance for the 
maximum residual F-parallax — do 0.02 mm in photo scale). The « base-in » — 
«base-out» procedure was applied. Three transfer points between adjacent models 
in the strip were used. These points are located in the center and at the strip edges 
of the common area between the two adjacent models. Scale transfer was performed 
by means of the elevations of the transfer points, and the coordinate transfer was 
done by using the center transfer point. Machine coordinates x and y (scale 1:20000), 
and elevations H of the given ground control points, the transfer points, and the test 
points, were recorded. 
dve test 
^ulation 
3ated in 
2. Photographic Material. 
The available RC7 diapositives were not of high quality. A fairly coarse grain 
and low contrast made the identification of the unsignalized ground control points 
and test points rather difficult. In addition, the presence of foreign objects, such as 
fibers and large dust particles, in the reproduction equipment (as evidenced by their 
images on the diapositives) indicated that the copying instrument was not clean. 
In one strip the complete loss of one fiducial marker and the frequent occurance of 
light flares indicates either insufficient care in reproduction or inefficient camera ope 
ration. Furthermore, emulsion scratches were prevalent, and in one case the emulsion 
had separated from the glass plate. This, together with emulsion stains and drying 
marks, leads one to suspect the presence of relatively large emulsion shrinkage. To 
test this suspicion a sample consisting of 50 photographs was selected, and measure 
ments of the fiducial markers were taken. A maximum range of emulsion shrinkage 
of 0.05 per cent was found which clearly proves the existence of a considerable emul 
sion shrinkage due to insufficient care in the reproduction of the glass diapositives. 
>rk was 
e, using 
3. Adjustment of the Wild Autograph Al. 
bructor. 
esearch 
3NTERO 
Owing to other commitments of the A7, the block triangulation « Massif Central » 
could not be triangulated in one step. This intermittent machine work was frustrating 
and made it necessary to examine and calibrate the Autograph A7 prior to each instru 
mental work period for the block triangulation. This had the advantage to assure a 
certain guarantee for a good adjustment status of the autograph when work was 
performed for the block triangulation « Massif Central». On the other hand, this