BRITISH NATIONAL REPORT 3 
B.K.S. AIR SURVEYS LIMITED have specialised in the production of large scale engineering 
plans, normally at a scale of 1:500 but also at larger scales such as 1:96 and they also undertake 
the computation of earthwork quantities and the determination of reservoir capacities. The 
company has been concerned in the development of aerial survey techniques in conjunction 
with the present Highways Programme and surveys have been carried out for the British 
Transport Commission, the Central Electricity Authority, water engineers, and for both 
local authorities and private concerns for housing and redevelopment schemes. 
The company has just started to use their new photogrammetric laboratory at Leatherhead, 
Surrey, and their photogrammetric department is at present equipped with three A.8 and one 
A.7 Wild plotting machines. 
MERIDIAN AIRMAPS LIMITED have carried out surveys at scales ranging from 1:360 to 
1:10,560, some with contours at vertical intervals of one foot at the larger scales of planimetry. 
The equipment used consists of Williamson L.S.P. plotters and Multiplex projectors and 
Williamson F.49, OSC and Wild RC.8 cameras which are carried in Auster Autocar and 
Airspeed Consul aircraft. 
Altogether some 135 square miles of surveys at scales of 1:2,500 and larger and some 1,270 
miles of profiles along road and railway routes have been completed. 
3. Non-Topographic Operations 
(Travaux qui ne sont pas Topographiques) 
(Unternehmungen die nicht Topographisch sind) 
THE DEPARTMENT OF SCIENTIFIC AND INDUSTRIAL RESEARCH makes use of photo- 
grammetry in its Road Research Laboratory to obtain a quantitative measure of the fine 
dimensional changes in the surface texture of roads which give rise to seasonal changes in 
their resistance to skidding. Special designs of camera and stereoscopic measuring equip- 
ment for this work have been made at the Laboratory which enable close-up pictures of small 
areas of the surface to be viewed at a ten times magnification and contours to be plotted to 
an accuracy of the order of 1:1,000 inch. The experiments are being made to study the 
changes in these contours, their influence on skid resistance, and the factors which give 
rise to them. 
Photogrammetry is also used in the Laboratory’s on-the-spot accident investigations to 
make quickly and accurately a permanent record of the accident site showing essential 
road features such as kerbs, markings, lamp standards, trees, road contours, and the position 
of the vehicles concerned. The Wild Stereometric camera C.12 and the Autograph A.4 have 
been used for this work, but single cameras for vertical photography (90° angle of acceptance) 
are under development; these cameras are supported at heights of up to 45 feet by a pneu- 
matically operated telescopic mast. 
UNIVERSITY COLLEGE LONDON. The reconstruction of the plans of the dome of Castle 
Howard (1701-1738: architect Sir John Vanbrugh) was carried out from photography obtained 
in 1920 for general architectural purposes (that is, not for photogrammetry). By taking a 
number of precautions and using somewhat unconventional methods an accuracy of about 
+2-5 cms. was obtained and this has enabled the architects to prepare working drawings for 
the rebuilding of the dome which was destroyed by fire in 1940. 
THE TRIALS DEPARTMENT OF THE ROYAL AIRCRAFT ESTABLISHMENT uses photogrammetry 
for the accurate measurement of guided missiles in flight at successive small intervals of 
time throughout the trajectory from release to impact. Trajectory measurements are also 
taken of the fall of bombs from aircraft. 
A method of computing the attitude of the round relative to ground axes from data 
supplied by two separated cine cameras has been used and a somewhat similar method is 
used for obtaining the miss-vector, i.e., the separation at the closest approach to the target. 
The method of obtaining the miss-vector and the attitude of the round relative to the target 
aircraft is by photographic triangulation with wide-angle cameras working simultaneously 
from the two wing-tips of the target aircraft. 
Two or more Vinten Type HS.300 cameras with lenses up to 80 inches focal length are used 
on special tracking mountings for cinematographic records of missiles in flight, from which 
the attitude of the round is derived. 
Cameras which are used for miss-vector distance measurement include the types G.W.1 and 
G.W.2 with lenses covering 143° and the Weapons Research Establishment type 1 camera 
which has a lens covering 180°. These cameras run at 100 frames per second for 6 and 12 
seconds respectively. The format is circular, approximately 1 inch in diameter. 
Two or more kinetheodolites are used for the measurement of trajectory. Exposures 
may be made synchronously in any required number of these instruments at rates of up to 
5 per second. Each instrument is aimed manually using binoculars. The positions in space 
of successive points of the trajectory are obtained by triangulation. 
A semi-automatic film analyser for the kinetheodolite records was designed for the Trials 
Department by the National Physical Laboratory and Messrs. Hilger & Watts Ltd. and is in 
use at the ranges. This machine, with the aid of an operator, reads the azimuth and elevation