SMALL-SCALE MAPPING DURING THE PERIOD 
1956 TO 1960 
Introduction 
The general situation in the field of small-scale mapping has changed little 
from that which existed four years ago. However, a certain evolution has taken 
place and there are developments underway that promise more spectacular changes 
within the next few years. In this brief review of the present state of the small- 
scale mapping technique we will stress elements that are new or that have been 
more intensively used during the period 1956 to 1960. Some of the opinions 
expressed here are based on the answers to the questionnaire distributed by 
Commission IV. The basic information on small-scale activity in various coun- 
tries is contained in three tables. 
Ground Control Survey for Small-Scale Mapping 
The establishment of the ground control constitutes an important phase of 
the small-scale mapping operation. Even in vast, underpopulated countries with 
low accuracy requirements, the official small-scale mapping program is based 
largely on field control surveys. There is a two-fold reason for this: first, 
various electronic means such as Shoran, which could reduce the volume of field 
operations, are too complex and expensive and therefore not practical. In addition, 
they only provide planimetric control with an accuracy that may not be sufficient 
for larger scales. On the other hand, the use of the airborne profile recorder is 
still in the initial stages, except in Canada and the U. S. 5. R. 
The second reason is that the general surveying and mapping of the country 
requires the establishment of monumented control points that could be used for 
any other surveying operations. Therefore, the establishment of basic ground 
control by means of field survey seems to be justified even if there should be 
no necessity for it from a purely cartographic point of view. This consideration 
is supported by the fact that a newly developed distance-measuring device, the 
Tellurometer, greatly facilitates field operations. 
Although the Tellurometer was not developed with a view to photogram- 
metric needs, its impact on photogrammetric mapping is enormous. Particularly 
incountries that are only partly mapped, the mainapplications of the Tellurometer 
are connected with the photogrammetric activity. 
In the main the Tellurometer is used to run first-order traverses over 
medium distances from 8 to 15 km. Longer distances would produce difficulties 
in angular observations and are measured rather by the trilateration procedure. 
A Tellurometer party equipped with a helicopter can establish 60 to 80 km of 
Tellurometer traverse with up to 15 traverse stations in one day. There is no 
doubt that the Tellurometer is a major advance in small-scale mapping in that 
it increases the economy and betters the quality.