Which survey device generates an infrared continuous wave carrier beam and measures the phase-shift of the reflected beam to determine the distance of an object?
A)Theodolite
B)EDM
C)GPS
D)Transit

Question

Quizplus · Accepted Answer

An EDM generates an infrared continuous wave carrier beam and measures the phase-shift of the reflected beam to determine the distance of an object. EDMs utilize the basic distance measurement principal of comparing a measurement to a known distance. With EDMs, the known distance is the wavelength of the modulation of a carrier wave.

Which Survey Device Generates an Infrared Continuous Wave Carrier Beam