An Evaluation of the Accuracy of an Autotape Survey

• Published in: The Canadian Surveyor
• Main Author: Pinch, M. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1971
• Subjects: General Earth and Planetary Sciences; General Engineering; General Environmental Science; Canada; Fort Simpson; Survey Point
• Online Access: http://dx.doi.org/10.1139/tcs-1971-0003; http://www.nrcresearchpress.com/doi/pdf/10.1139/tcs-1971-0003

In 1968 the Geodetic Survey of Canada established points approximately 25 kilometers apart on flat terrain near Fort Simpson, NWT, by trilateration methods using autotape equipment and a helicopter. Both line-crossing and hovering techniques were used. Second-order accuracy was anticipated; however, reduction of the field data, using least square adjustments, showed that only third- and fourth-order accuracy had been attained owing mainly to deficiencies in the hovering technique. The methods used to determine when the helicopter was at the zenith of the survey point were inadequate for the high altitude hovering necessary during measurement. If second- or even third-order accuracy between hover points 25 kilometers apart is to be obtained, better methods of hover control will have to be introduced.