A Doppler velocimeter apparatus that may have a coherent light source for generating a beam of coherent light. A modulating subsystem may receive and modulate at least a first portion of the beam of coherent light to form a first beam portion, the first beam portion forming a frequency offset and being a modulated, coherent optical signal. An optical element may receive the first beam portion and direct the first beam portion at a subject, the first beam portion being reflected from the subject to form a reflected beam that has a frequency that is modified in relation to the motion of the subject. A processing subsystem may receive a second portion of the beam of coherent light, and also the reflected beam, and uses the second beam portion and the reflected beam to determine a Doppler shift of the reflected beam.