TENTH INTERNATIONAL CONGRESS 
OF PHOTOGRAMMETRY 
BRITISH NATIONAL REPORT 
this report covers the period between the Ninth International Congress of Photogrammetry 
held in London in September 1960 and 31st December 1963. Publications that have appeared 
in 1964 before the printing of the report have been included. 
1. Introduction 
(Introduction) 
(Einleitung) 
The period under review has seen a considerable increase in the use of photogrammetry by 
British organisations engaged on preparing maps and plans at home and abroad. The interest 
in digital methods continues to be sustained and there have been significant improvements 
in both methods and equipment. There has not perhaps been any great increase in the use of 
fully digital methods outside the Ordnance Survey but digital methods are being increasingly 
used in independent model triangulation and in block adjustment. 
There has been a very noticeable increase in the use of photogrammetric methods in 
problems connected with road location and construction including the computation of earth 
work volumes. This is also an indication of a tendency for the more direct use of photo 
grammetric processes in engineering without, necessarily, the intermediate step of map 
production. 
2. Survey Operations 
(Travaux Cadastraux et Topographiques) 
(Vermessungunterrehm ungen) 
The Ordnance Survey of Great Britain is continuing to survey uncontoured plans of 
urban areas at a scale of 1:1250 and the proportion of these produced photogrammetrically 
has been increased during the period covered by this report in which 666 sq. kms. have been 
plotted. Air survey techniques have been introduced in the revision of the 1:2500 uncontoured 
plans of rural areas; up to 31st December 1963, 4374 sq. kms. have been air revised, and one 
area of 85 sq. kms., where a revision would have been inadequate, has been resurveyed at 
this scale. Work continues at an increased rate on the resurvey of the mountain and moorland 
areas of the country at a scale of 1:10560, the largest scale of mapping in these areas, with 
contours at a vertical interval of 25 feet (31); 11,583 sq. kms. have been plotted in the period 
reported. Contours, at the same vertical interval, are also being plotted on the 1:10560 maps 
derived from larger scale plans, and 7894 sq. kms. have been contoured. The photogrammetric 
equipment used for resurvey and contouring includes ten Thompson Watts plotters (Mk. I, 
Mk. IA and Mk. II), nine Wild plotters (A.8 and A.5) and four Santoni Stereosimplex; seven 
Grant projectors and a Santoni Stereomicrometer are used for air revision, as also are rectified 
enlargements made on a Zeiss Seg V rectifier. A cyclic tidal survey is also being carried out 
with graphical plotting from infra-red photography. 
The Department carries out all stages of the aerial survey including flight planning, taking 
and processing aerial photography, aerial triangulation where required, the actual plotting 
and a subsequent ground completion. Aircraft were provided by the Ministry of Aviation 
Flying Unit but in 1963 one additional aircraft was also hired from a civil firm and this will 
be repeated. 
The areas photographed during the period covered by this report are 795 sq. kms. at scales 
of 1:4000 to 1:5000 for 1:1250 surveys, Î9402 sq. kms. at scales of 1:5000 to 1:8000 for 1:2500 
surveys, 32,575 sq. kms. at a scale of 1:24000 for 1:10560 surveys, and 2181 miles of tidal 
photography. Williamson F.49 cameras fitted with réseaux and Ross 6-3" or 12" lenses are 
used, a Zeiss 12" non-réseau camera is being purchased for use in 1964 and trials are in hand 
to select a new 6" réseau camera. 
The technique of analytical aerial triangulation, used by the Department for the control 
of all the 1:10560 resurvey and a small proportion of the 1:1250 resurvey, has been continuously 
improved (49) over the period covered by this report. Observations are made on one Hilger 
and Watts automatic recording stereocomparator and five Cambridge stereocomparators, 
computations are performed on the DEUCE and ACE electronic computers at the National 
Physical Laboratory. 
The Directorate of Overseas (Geodetic and Topographical) Surveys, part of the 
Department of Technical co-operation, assists the developing countries overseas in the basic 
surveying and mapping of their territories. Most of its mapping output is topographical maps 
produced from air photography.