5 
auxiliary data, and restraints to keep lakes level, and to fit various types of vertical control that have different 
degrees of reliability. 
During the past few years, the energy of the photogrammetrist involved in designing computer programs 
has been dissipated because of the rapid changes in available computer systems. In 1958, programs were avail 
able on the IBM 650 system. These were converted and modified to the IBM 1620, to medium size computers 
and more recently to the IBM 360 systems. It is hoped that computer systems will stabilize for a period of time 
so that advances can be made in adjustment techniques rather than recoding whole programs to keep pro 
duction in step with the changing computers. 
Auxiliary data 
There is not as wide usage of auxiliary data in Canada as one might expect. Most of the country outside 
the population belt has been covered by suitable photography for some time. The rapid change in computers 
retarded the development of suitable computer programs that would accept auxiliary data as parameters in 
the adjustment. From the questionnaire, it is apparent that APR, simultaneous with air photography, is the 
most widely used auxiliary aid. APR is also used to provide vertical control for existing photography, in which 
case it is not an adjustment parameter in the air triangulation. There is a limited use of the statoscope and the 
horizon camera, although there is a considerable Canadian capability in both techniques. 
Aerodist positioning photography with simultaneous APR is one of the main methods of obtaining 
horizontal control for medium and small scale mapping in the national program. Depending upon the size of 
the areas to be mapped, 6 to 10 maps, each 15' x 15', are surrounded by aerodist controlled photography. 
As yet, blocks of mapping have not been flown completely with aerodist controlled photography. 
Trends for the future 
Computer programs for the adjustment of single model aerotriangulation are now in the development 
stage. Although it is difficult to predict what might happen in the next few years, one could expect that if single 
model adjustment programs are available, there will be a definite reluctance to purchase first order aerotriangula 
tion instruments because of the large number of first order plotting instruments available. This will be par 
ticularly true in mapping organizations where the volume of aerotriangulation is relatively low and where 
first order instruments are used for both plotting and aerotriangulation. 
COMMISSION IV 
Mapping from Photographs 
Reporter: Dr. J. M. Zarzycki, Terra Surveys Ltd., Ottawa. 
During the period 1964-1968, activities in the field of photogrammetry in Canada increased in proportion 
to the demand for small and large-scale mapping of the country. The basic topographical series are at scales 
1/250,000, 1/125,000, 1/50,000 and 1/25,000. Maps for forest inventory are prepared at scales of 1/24,000 and 
1/14,840, depending upon the province. The most common maps for town planning and urban development are 
at scales of 1/2,400, with five-feet contours, for built-up areas, and at 1/4,800, with five or ten-feet contours, 
for rural areas. For detailed engineering planning, maps are prepared at a scale of 1 /480 or 1 /600, with one-foot 
or two-feet contours, and, for special projects, at scales as large as 1 /240. 
During the last four years, photogrammetry found an increased acceptance by civil engineers with the 
result that photogrammetric methods are becoming fully integrated with engineering design. 
In Canada, the responsibility for highways rests with the provincial governments, with the exception of the 
Trans-Canada highway, which is the responsibility of the federal government. The acceptance and utilization 
of photogrammetric engineering to solution of highway engineering problems varies throughout the country. 
The Ontario Department of Highways is r most advanced and has a fully equipped and qualified photogrammetric 
division. The trend in the past has been for the provincial Departments of Highways not to become deeply 
involved with photogrammetric instrumentation, relying on the private consultants to provide these services. 
For highway engineering, plans are compiled at scales of 1/4,800, 1/2,400 and, for detailed design, 1/480. 
Cross sections are compiled photogrammetrically for detailed design of multi-lane highways. In addition, 
aerial photographs are employed to carry out area studies and engineering soils investigation. 
Photogrammetry is employed to provide the necessary terrain information for location of transmission 
lines and pipe lines and is used extensively for log pile and open-pit mine inventories. 
The basic mapping of Canada is carried out by the Surveys and Mapping Branch of the Federal Department 
of Energy, Mines and Resources. A number of provinces have small photogrammetric facilities for forestry 
mapping or for application to highway engineering. The private photogrammetric companies in Canada are 
carrying the task of large-scale mapping, mostly for urban and regional planning, highway and railway location, 
and the mining and oil industry, as well as for consulting engineers. In addition, the private companies have 
carried out photogrammetric mapping projects, under the auspices of Canadian External Aid, in Africa, South 
America, Asia, and the Caribbean.