COMMISSION II 
Theory, Methods and Instruments of Restitution 
Reporter: R.A. STEWART, Surveys and Mapping Branch, Ministry of Energy, Mines and Resources 
Over the past four years, there has been an accelerated and widespread conversion from the previously 
predominant anaglyphic (optical projection) plotting instruments to higher order mechanical projection plotters, 
This is the case across the entire spectrum of Canadian surveys and mapping endeavour - at all federal, pro- 
vincial and commercial agencies engaged in photogrammetric work, The previous barrier of the higher capital 
investment required for 1st order plotters has been broken by the consideration of the economies that are realized 
by the employment of higher order instruments and their applicability to automation, 
The federal mapping agency, i.e. the Topographical Survey Directorate, surveys and Mapping Branch, 
Ministry of Energy, Mines and Resources, is responsible for the national topographic mapping programme and 
employs 60 plotting instruments, ranging from lst order through 3rd order. Their conversion from anaglyphic 
to mechanical projection plotters is at this time 65% completed. Five of the ten provincial governments have 
mapping capabilities, and they are equipped predominantly with high order plotting instruments, Ninety percent 
of the twenty-four private mapping companies across Canada have first order restitution instruments - slightly 
over fifty plotters in number, Three Universities, the National Research Council and several technological 
institutes are well equipped with high order plotting instruments, 
The influx of high order restitution instruments has been accelerated to a considerable degree by recent 
widespread utilization of the independent models method of aerotriangulation, Using a single higher order 
restitution instrument, smaller firms can now perform both aerotriangulation and compilation to a high degree 
of accuracy. 
The remaining requirement for the basic 1:50, 000 mapping coverage of Canada lies in the northern 
hinterlands. A very great area still remains to be done. For the northern country, the majority of users still 
request that conventional line maps be produced. However, there is a growing demand for photomaps (either 
photoplan or full orthophotomap) through a wide range of scales, from across the length and breadth of the 
country, and for a wide range of clients, 
Thus, while the major portion of the national effort in photogrammetric restitution is still being accomplished 
by conventional optical-mechanical plotting instruments, many private and governmental agencies have acquired 
orthophoto producing instruments and are producing photomapping as a standard procedure, 
It is in the field of orthophotography that Canada is playing a leading role among the nations of the world, 
After their initial successes with the Stereomat in the early 1960's, what is now the firm of Hobrough Ltd. 
has produced the Gestalt Photo Mapper, a high-speed computerized orthophoto printing system employing auto- 
matic image registration, This instrument has enjoyed a considerable degree of success over the past two years 
and improvements are being developed for ensuing models, 
The National Research Council is proceeding with their development of a stereo-orthophoto mapping system, 
This system consists of several innovations, The Orthocartograph instrument produces simultaneously an ortho- 
photo plus its "stereomate'', The stereomate is a special continuous-image photograph in which the X-coordinates 
of points are changed by horizontal parallaxes proportional to the elevation differences. The orthophotograph and 
its stereomate are then viewed in a relatively simple instrument called a Stereocompiler, and compilation, con- 
touring and photo interpretation are performed by direct viewing. By overlaying a transparent drafting sheet 
over the image, both the stereo model and the plotting can be observed continuously by the operator, A contouring 
table and provision for automatic hill-shading complete the total system, 
The Photogrammetry Office, Ontario Ministry of Transportation and Communications, has developed a 
photogrammetric digitization system that is employed principally for the recording and subsequent compilation 
of transportation systems in the Province of Ontario, 
Developmental work continues in the Surveys and Mapping Branch, Ministry of Energy, Mines and 
Resources, on automated terrain digitization procedures for new mapping, map revision and map generalization 
for special purpose mapping. 
COMMISSION III 
Aerial Triangulation 
Reporter: J.R.R. GAUTHIER, Surveys and Mapping Branch, Ministry of Energy, Mines and Resources 
In Canada, the period of 1968 to 1972 was one of consolidation for aerotriangulation, Graphical methods 
of adjustment were completely abandoned and aerotriangulation became an accepted method of control densifi- 
cation for large scale mapping. The period of 1972 to 1976 should be one of renewed progress when rigorous 
methods of adjustment developed in the sixties become production tools in mapping. These adjustment methods 
will further reduce the amount of ground control required, and will increase the accuracy of aerotriangulation 
results,