A high-resolution incoherent-detection Doppler lidar has been constructed at the University of Michigan Space Physics Research Laboratory. The lidar uses multiple Fabry-Pe´ rot interferometers to measure the Doppler shift of aerosol-backscattered light and to attenuate background light. In this way, vertical profiles of the horizontal wind field are obtained with high spatial and temporal resolution. It has been found that if the transmission functions of the etalons are not properly aligned, a systematic error in the Doppler-shift determination can result. This error is dependent on the relative aerosol loading of the atmosphere and can be quite large. For large etalon offsets the wind error can be in excess of 10 m/s. Even for small offsets and high aerosol loadings, the wind determination can be biased by as much as 1 m/s. A previously developed model and inversion process can be modified to allow for an offset between the etalons and recover data without bias.