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UNIVERSITY OF LONDON:
UNIVERSITY COLLEGE LONDON, Department of Photogrammetry and
Surveying
Access to some original papers of F V Thompson led to an investigation of the
Vivian Thompson stereo-planigraph (142). This hitherto unpublished design dates
from 1908 and relates to an automatic plotting instrument for terrestrial photo-
graphs. It is historically important because this design pre-dates Pulfrich's
solution of the problem, based on von Orel.
Further developments in the use of the Cartographic Engineering plotter CP1 for
off-line contour plotting are in progress (57), assisted by a substantial grant
from the R W Paul Instrument Fund administered by the Royal Society.
Work on the calibration of plotting instruments (55), on their day to day use by
photogrammetric operators (150), and on aspects of aerial triangulation (60, 108)
and the measurement of photographs (144) has continued. In addition, contribu-
tions to the theory of space resection and convergence have been published (146,
145).
MEAT RESEARCH INSTITUTE, Agricultural Research Council
Moiré methods have been used to obtain contours of equal depth on photographic
records of living animals and carcasses. A technique has been devised which
allows the levels at which contours are observed to be adjusted after a record
has been taken.
MOORFIELDS EYE HOSPITAL, Glaucoma Unit
A stereophotogrammetric method for measuring the depth of the optic disc in
glaucoma has been developed using a retinal camera with an image separator
(67). The accuracy of the method has been assessed and found to compare
favourably with other clinical methods of optic disc depth estimation. This work
was awarded the Combined Royal Colleges Medal for 1974 as the outstanding
example of photography in the service of medicine and surgery.
NATIONAL PHYSICAL LABORATORY, Division of Mechanical and Optical
Metrology
Using holographic methods, a number of practical problems in engineering
requiring the recording and subsequent measurement of movements and distortion
inthe surfaces of solid bodies and changes in density in gases have been solved
(72, 73). Special methods using multiple pulse lasers have been evolved for the
measurement of transient changes and movements necessitating repetition at
intervals down to a few microseconds.
A programme has begun to develop new methods of locating points in a 3
dimensional space by the use of coherent light, with the prime objective of
providing for a calibration of three dimensional measuring machines.
A technique (3, 4, 5, 68) for measurement of plane surface displacement has been
developed, in which a double-exposure photograph of the laser-illuminated object
is recorded on the same frame of holographic film, before and after deformation
has taken place. By examining the diffraction pattern generated by the speckle
pattern recorded at individual points on the negative image, the local displacement