The representativeness and accuracy of laser Doppler anemometer (LDA) mean wind velocity measurements in the planetary boundary layer under different conditions of atmospheric stability and earth surface roughness is studied, both theoretically and experimentally, for two measurements techniques: 1) Velocity-Azimuth-Display (VAD) and 2) Doppler Beam Swinging (DBS). In many instances LDA measurements better represent true mean wind than traditional point measurements, because of measured spatial temporal averaging.