Die Geodatische Erschliessung Kanadas Durch Elektronische Entfernungsmessung

Since the end of the war, the electronic methods for measuring distances have made considerable progress and very remarkable new possibilities in the field of surveying techniques have been found. Means originally serving war purposes only have been adapted to civilian and economic use by con­ tinued development of methods and equipment. After a survey on the conventional methods of triangulation applied in Germany and the United States and after a brief discussion of modern base measuring by means of the intcrference method according to Vais?la and the geodimeter according to Bergstrand, the Canadian trilateral method is taken as an example to show the specific possibilities the Shoran and the Hiran methods, developed from radar techniques, oHer to-day to a geo­ desist for exploring virgin areas. By these methods distances of about 300 to 400 kms can be measured with relatively high accuracy. The longest distances so far covered by one direct Hiran surveying action is known to be 884 kms (see page 55, note 20). Technical problems in the field of surveying arising in connection with the Shoran method are the main subjects, such as the calibration of instru­ ment reaction delay, the measuring and determining of the minimum sum and the reduction of the measured lengths to distances on the ground. Fur­ thermore, the accuracy achievable with Shoran or the more advanced Hiran­ system is discussed in detail, based on the Canadian results obtained during the period 1949 to 1953 and subsequent experience.