18 
Improved methods of identifying ground control, both by pre-marking and 
photo-identification, have been investigated. A portable Polaroid enlarger for 
field surveyors is being tested. 
There has been considerable experimentation with photo-mechanical 
techniques to reproduce photographic detailas a background for printed maps 
(59). Considerable success has been achieved in this field, though the 
procedure is restricted to flat country. Research has also been undertaken into 
the portrayal of under water features by photo map techniques. 
The Land Resources Division has further refined the method of land use 
analysis by means of stereoscopic identification of sample points on air 
photographs and subsequent processing of the data by computer. This method 
has now been used in Nigeria, Malawi and Gambia. Comparative studies of 
colour, infra-red and panchromatic black and white films, using both prints 
and transparencies or diapositives, have been made. 
ENVIRONMENT Dept. of the 
A recent development in the Department of the Environment has been the 
institution of a Central Register of Air Photography of England, and for the time 
being also of Wales, containing particulars not only of Ordnance Survey and 
RAF cover but also of other photography. A similar Register for Scotland is 
operated by the Scottish Development Department, York Buildings, Queen Street, 
Edinburgh. 
EDINBURGH UNIVERSITY. School of Built Environment 
Photogrammetry was used during the excavations of Saliagos. An 
inexpensive photogrammetric approach to the reduction of diving time has been 
developed, and a photogrammetric method for recording the underwater 
distribution of marine benthic organisms. A paper of instructions has been 
written for a simple submarine photogrammetric technique, and field trials 
have been undertaken for a new method of excavation photogrammetry. A 
current work is in hand which will deal with submarine mosaics. (126, 127, 
129, 130) 
FAIREY SURVEYS LTD 
During the period 1968-1971, the Company has increased its number of plotting 
instruments by three, by the purchase of Zeiss (Jena) Stereometrographs E and 
D and à Zeiss (Jena) Topocart B with Orthophot and Orograph attachments. The 
use of numerical methods in photogrammetry has been intensified considerably 
during the period and all aerial triangulation adjustments are now done using 
electronic computer programs. For this purpose, the Company has been 
operating through a time sharing computer terminal as well as using outside 
bureaux for batch processing of data. IBM 360 series and ICL 1900 series have 
been used mainly. A large number of digital ground models have been produced 
for clients in the UK mainly Road Construction Units of the Department of the 
Environment. The data is supplied to the clients either on punched cards, 
punched paper tapes or on magnetic tape. 
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