| 17 Sep 2025
Improving Wind Speed Availability of a Six-Beam Doppler Lidar
Abstract. A simple adaptive variant of the Doppler Beam Swinging (DBS) method is presented to enhance the availability of wind velocity measurements in profiling lidars. The adaptive method dynamically selects beams with sufficient signal-to-noise ratios (SNR) for wind velocity reconstruction, instead of the standard approach, which discards a complete scan when one beam falls below the SNR threshold. The adaptive method was validated in two measurement campaigns at the Østerild wind turbine test field in Denmark using three BEAM 6x profiling lidars from Lumibird. In the first campaign, a lidar measured up to 500 m in proximity to a meteorological mast; in the second campaign, the first lidar was replaced by two other lidar units to increase the maximum measurement range up to 1 km. Validation against cup anemometers and wind vanes at four different heights of the met mast showed excellent agreement for mean wind speed and wind direction, with results similar to those from the standard approach. Availability assessments indicated improvements for all three lidars at high altitudes, showing a maximum increment of 16.9 percentage points over the standard approach. Due to its simplicity, the adaptive method can be implemented in lidar software without requiring any hardware modifications.
Competing interests: JM holds a chief editor position in the Wind Energy Science (WES) journal. MM, GL, and GG are employed by Lumibird SA.
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The manuscript is well-written and presents the information in a clear and straightforward manner. I am concerned, though, that the new method for filtering DBS scans presented here is behind the state-of-the-art. For instance, Steinheuer 2022 (see below) introduces a method to filter DBS and VAD scans and adaptively reject low-quality measurements. An added benefit is that they use radial wind speed only, avoiding issues associated with fixing an SNR cut-off (which should vary with lidar settings). I would like to see more thought given to other methods such as the one they propose, or direct comparisons against results employing other methods. Or, if other methods are inappropriate for use on the lidar hardware itself given hardware limitations, that could be noted as well. That is, the proposed method might be preferred for running onboard the lidar given its simplicity. In any case, additional justification is needed for the current method compared to other methods.
J. Steinheuer, C. Detring, F. Beyrich, U. Löhnert, P. Friederichs, and S. Fiedler, “A new scanning scheme and flexible retrieval for mean winds and gusts from Doppler lidar measurements,” Atmospheric Measurement Techniques, vol. 15, no. 10, pp. 3243–3260, May 2022, doi: 10.5194/amt-15-3243-2022.