Described herein is a method and system for mitigating the effects of speckle in a laser Doppler system, and, in particular in a laser Doppler vibrometry/velocimetry system. A scan unit is provided in at least one of: a transmit path for scanning at least one beam from a transmitting antenna over a moving target surface and a receive path for scanning at least one reflected beam received from the moving target surface onto a receiving antenna. An averaging unit is provided prior to post-processing or demodulation to average electrical signals corresponding to the reflected beams. By averaging before demodulation, speckle in the output signal is mitigated.