AN ALIDADE FOR USE WITH ELECTRO-OPTICAL DISTANCE MEASUREMENT
A. L. Allan · Survey Review · 1977
In this paper a Polar Alidade is described which has been developed by the author for use with EDMin either of two ways (i) as an ancillary or satellite instrument, or (ii) with the EDMinstrument mounted on top (as an alternative to a theodolite). (See reference 1.) The Polar Alidade records directions by punching fine holes in stable plastic sheets to an accuracy of 1:3000.