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BRITISH NATIONAL REPORT
As indicated, mapping is undertaken at various scales, but the majority of work is topo-
graphical mapping at a scale of 1:50,000.
Photogrammetric plotting equipment in use consists mainly of 148 Williamson Multiplex
projectors, a Thompson-Watts plotter, a Wild A.5 and two Zeiss C.6 Stereoplanigraphs;
further equipment is on order. Multiplex is used mainly for contouring but also in certain
cases for supplying detail For the 1:50,000 and smaller scale mapping, detail is usually
plotted by graphical methods - based on a slotted template assembly. When multiplex is
used for detail the multiplex plots are adjusted by means of a stereotemplate assembly.
Larger scale mapping at scales varying from 1:25,000 to 1:2,500 is usually undertaken in
the Directorate's first and second order plotters with aerial triangulation being used to
break down existing control. A Jerie L' T.C. Analogue Computer (12) has recently been
acquired to assist in adjustment.
Special purpose maps are also prepared to a large variety of specifications and scales.
Most of the photography for mapping is undertaken under contract by civilian firms who
use Wild R.C.5 and R.C.8 survey cameras.
FAiREY AIR SumvEYs LiMiTED have changed their name from "The Air Survey Company
Ltd" since the Eighth Congress.
During the past four years Fairey Air Surveys Ltd. has photographed an area in excess of
450,000 square miles. Photographic scales have varied from 1:3,000 to 1:50,000 and
practically all of this work has been undertaken using the Aviogon 152 mm. lens. The types
of aircraft used are Douglas DC.3, de Havilland Dove and de Havilland Rapide. Visual
navigational methods have been used throughout.
Operations have been undertaken in many parts of the world, the principal areas being
Burma, the Federation of Rhodesia and Nyasaland, lran, East and South Africa, British
Guiana and Pakistan.
Geophysical surveys have been made in various parts of the world, using magnetic, electro-
magnetic and radiometric methods. Among the more interesting geophysical surveys
carried out was one using two de Havilland Dove aircraft in Tanganyika and covering
approximately 100,000 line miles of radiometric survey.
During the period under review the mapping undertaken by Fairey Air Surveys has ranged
from ultra-large scale railway and engineering surveys at a scale of 1:500 to contouring at
1:100,000 scale. The more important projects have included the use of the Airborne Profile
Recorder (6) over an area of 17,000 square miles in the Protectorate of Aden, the mapping of
an area of 7,250 square miles at 1:12,500 scale in the Caribbean and of some 130,000 hectares
at a scale of 1:2,500 on behalf of the National Cartographic Centre of Iran.
Aerial triangulation and intensification of control continues to be carried out in the Zeiss
Stereoplanigraph C.8, now supplemented by the Jerie LT.C. Analogue Computer for block
adjustment (12).
A number of surveys have been made for cadastral and land tenure purposes, involving
both a graphical and numerical cadastre.
HunTING SURVEYS LIMITED (amalgamation of the former Hunting Aerosurveys Ltd. and
Hunting Geophysics Ltd.) have undertaken planimetric and topographic mapping on a wide
range of plotting instruments at scales ranging from 1:480 with 1 ft. contours to 1:100,000.
The Hi-Spec photogrammetric electronic computation technique has been used for highway
and railway construction projects, stockpile measurements and work involving accurate
determination of profiles, cross sections and volumes of earth or other materials.
In 1956-57, Huntings completed a 31,000 square mile survey in Grahamland; for this very
difficult Antarctic territory shipborne helicopters were used to move the ground triangulation
teams. 37,000 square miles have been mapped since 1957 at 1:20,000 scale for a national road
construction project in Ethiopia and plans at 1:2,000 have been prepared for Addis Ababa.
Further road and town planning surveys have been carried out in Afghanistan, Iran, Pakistan,
East Africa, Persian Gulf Area and the United Kingdom.
In Africa alone, over 300,000 square miles have been photographed, more than 150,000 line
miles of geophysical survey have been flown, and extensive ground geological investigations
have been undertaken for oil exploration since the 1956 Congress. Widespread geophysical
surveys for minerals with the airborne radiation detector and electro-magnetometer have
been completed.
In 1958 comprehensive tests with the Airborne Profile Recorder (6) were carried out over
a well mapped area in South Wales for a detailed assessment of the instrument required by
the then Ministry of Supply. More recently the Airborne Profile Recorder has been used on
an engineering survey in West Africa with conspicuous success.
The company has recently carried out photography of extensive areas employing the Wild
R.C.9 super wide angle lens and it is believed that super wide-angle photography combined
with the Airborne Profile Recorder and the Doppler Navigator will introduce significant
economies in small scale mapping. Successful use has also been made of the distances
recorded by the Doppler Navigator for controlling mosaics.
Hunting Technical Services Ltd., have carried out resources and geological studies in
Sudan, East Africa, Algeria, Iraq, Iran, Pakistan, Burma, Cyprus and Italy since 1956.
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