BRITISH NATIONAL REPORT 
5 
3. Non-Topognaphic Operations 
(Travaux qui ne sont pas topographiques) 
(Unternehmungen die nicht Topographisch sind) 
Relatively little non-topographical work appears to have been done in Great Britain during 
the period from 1960. Attempts have been made to apply photogrammetric processes to the 
systematic recording of National monuments, but without great success: the difficulties 
having been administrative and not technical. The University of Glasgow has undertaken 
a survey of Glasgow Cathedral which is in progress. The Marconi Company has applied 
photogrammetric methods to the measurement of large radio aerials and Imperial Chemical 
Industries have used the methods in connection with complicated pipe-line layouts. 
Valuable work has been done in soil and vegetation classification by University College 
London, Glasgow University and Bristol University. 
4. Development of Equipment, Methods and Research 
(Développement du Material et des Recherches) 
(Entwickelung von Ausrustung und Forshung) 
The period under review has seen the production of a high-resolution, wide angle lens of 
f.5-6 aperture by the Wray Optical Company. A new wide-angle (Eagle 10) camera has been 
developed by the Williamson Manufacturing Company with a shutter whose basic design 
was evolved by the Royal Aircraft Establishment, Farnborough and which incorporates 
contra-rotating co-axial disks with sector cut-outs. The shutter has an efficiency of 80 per cent 
at f.8 with speeds varying from 1:250 to 1:1250. 
The Automatic Recording Stereocomparator exhibited at the Ninth Congress by Messrs. 
Hilger and Watts has been fully developed with a new transistorised recording system. The 
Thompson-Watts Plotter Model 2 is now in production with a number of improvements made 
as a result of experience with the prototype exhibited in London in 1960. Messrs. Hilger and 
Watts have developed an examination mirror stereoscope which incorporates a new device 
for parallax measurement in which the floating marks are optically projected into the system 
and form an integral part of the stereoscope. Messrs. Fairey Surveys continue their work on 
anti-vibration mountings and their most recent development is a mounting for a six inch 
camera with remote control of yaw and pitch. 
The Ordnance Survey has been able to improve the quality of air photography, taking 
advantage of finer grain emulsions now available with suitable speeds, and by exposing a 
test strip of photography in each sortie and using this to determine the most suitable developer 
(49). Modern cameras are expected to improve results further. A test for flatness of the film 
at the instant of exposure is carried out as a routine (51). Laboratory methods of camera 
calibration have now replaced that by horizontal photography of a field calibration range (48) 
The system of analytical aerial triangulation using réseau photography has given results 
of steadily increasing accuracy, assisted by the Hilger and Watts automatic recording stereo 
comparator, more of which will be purchased. The block adjustment of aerial triangulation 
has now been programmed for the DEUCE and ACE electronic computers and these pro 
grammes have replaced the use of the Jerie-I.T.C. Analogue Computer giving a considerable 
economy (47). 
Direct scribing of contours in plotting machines has been adopted in the 1:10560 resurvey 
and most of these can be accepted as production documents with only minor improvements 
at the drawing stage. 
The introduction of air revision to the 1:2500 programme was the result of experiments 
which demonstrated its economy over the normal ground revision used hitherto. It is now 
intended to revise about half the remaining 1:2500 plans from air photography. A technique 
has also been developed whereby built up areas, difficult to revise, can be completely replotted 
and let into the revision documents, using only these documents as control. 
Trials continue with a view to acquiring an improved 6" focal length réseau camera. Réseau 
cameras being tested include those manufactured by Messrs. Hilger and Watts, Wild and 
Zeiss. 
The Directorate of Overseas Surveys has developed a production method of aerotri- 
angulation using the Wild A.8 plotter with EK5a readout and the Pegasus electronic computer. 
Trials have been made with various stereocomparators and further research is in hand to 
investigate the practicability of completely analytical air triangulation. 
For general purposes, and to make possible the use of Super Wide Angle cameras for air 
triangulation and contouring, the Directorate has purchased a Kern P.G.2 plotter. New 
techniques for the use of this instrument have been tried and developed, and two more 
instruments should be in use before September 1964. 
Trials and research have been carried out in connection with the various processes involved 
in the production of air photography, premarking of control points, and the use of auxiliary 
height data techniques.