Canada 2 
employing a large number of aircraft and several hundred personnel and there 
are in addition three or four small mapping companies. 
Photogrammetry is not as yet used to any significant extent for cadastral 
survey, because generally speaking, photogrammetric surveys have no legal 
status for land title registry purposes. Since the great majority of property 
boundaries are straight lines, ground surveying and monumenting is simplified, 
and in general can be carried out more effectively, if not more economically 
than photogrammetric surveys. 
Most urban maps are produced for local authorities by commercial firms. 
Compilations are carried out by precision plotters such as the Wild A8 for a 
publication scale of 1/1,200 to 1/5000 with 2/ 2 to 5 foot contour intervals. They 
are used for assessment, town planning, engineering planning, real estate de 
velopments etc. The demand for such maps has increased greatly in recent 
years and there is every probability that it will continue to do so for some time. 
In general, small scale mapping is exclusively a function of the Federal 
Government, except in the province of British Columbia where federal mapping 
resources are augmented by the provincial survey organization. 
Until recently, horizontal control for standard topographic maps was 
established almost exclusively by ground triangulation and/or traverse, and 
vertical control by spirit levels supplemented by trignometric levelling and 
aneroid altimetry. However, with an ever increasing proportion of the mapping 
being devoted relatively inaccessible areas of the country, other methods, mostly 
dependent upon the use of aircraft, have come into use. Examples of these 
are astronomical fixes, electronic fixes and air-borne flare triangulation for 
horizontal control, while radar altimetry has come into prominence for the 
major part of vertical control. Within the past seven years, the Canadian main 
land has been almost completely covered with a net of shoran trilatération with 
sides averaging approximately 320 km in length and some 1,500,000 km 2 of this 
area has been covered by a grid at approximately 30 km interval of shoran 
controlled photography. Radar altimeter profiles originally adopted for use 
with 1/500,000 maps for reconnaissance elevations have now attained an accuracy 
suitable for use on some types of 1/50,000 maps. 
The bulk of topographical mapping is confined to scales of 1/50,000 and 
1/250,000, though for special purposes a few maps at scales of 1/25,000 and 
1/126,720 are produced. To indicate the rate of progress the table below gives 
map coverages in 1950 and 1955: — 
Map Scale 
1/50,000 
1/126,720 
1/250,000 
1950 Coverage 
450,000 km 2 
134,000 km 2 
1,850,000 km 2 
1955 Coverage 
1,050,000 km 2 
207,000 km 2 
3,360,000 km 2 
In addition to the foregoing, the Canadian mainland and Arctic Islands 
have been completely covered by the 8 mile=l inch map series which is intended 
primarily for aeronautical purposes. These maps were compiled largely from 
trimetrogon photographs controlled by astronomical fixes. 
Development 
A Photogrammetric Research Section has been established within the 
National Research Council. This section, equipped with a good variety of 
precision plotters and staffed by photogrammetrists of international repute, is