Windspeed determination from a near-field, UV, direct-detection Doppler wind lidar based on Michelson interferometer...

The determination of the wind speed from direct-detection Doppler wind lidar (DD-DWL) instruments is a crucial part within their development and operation. The previously developed AeroLi system [Appl. Opt.55, 6910 (2016)APOPAI0003-693510.1364/AO.55.006910; Remote Sens.14, 3356 (2022)RSEND32072-429210.3390/rs14143356] utilizes a fringe-imaging, field-widened, and skewed Michelson interferometer as its spectral analyzer. In this communication, we focus solely on the analysis of the imaged linear interference fringe for the derivation of the wind speed. For this, a process of different operations is necessary, including multiple corrections and regression operations. We describe this process in detail and investigate the influence of the different steps (in particular correction of the illumination, contributions of the laser reference and atmospheric contribution) on the final results of windspeed dispersion, bias, and correlation with a reference DWL. By providing a series of case studies we also demonstrate the performance of this realization of a DD-DWL as adequate for its intended use case in an aeronautics application. We assume these steps and considerations as relevant for developments of fringe-imaging DWL in general, or by extension for any lidar system with imaging analysis of a spatially distributed signal.