| 15 Jul 2026
Beyond the Intersection Point: Offshore Wind and Turbulence reconstruction from Horizontally Separated Dual-Doppler Scanning Lidar Beams
Abstract. Dual-Doppler scanning lidars (DSLs) are increasingly considered a promising technology for offshore turbulence characterization, yet their performance at long offshore ranges and their sensitivity to spatial separation between reconstructed measurement volumes remain largely unexplored. Conventional DSL configurations require the two lidar beams to intersect at a common measurement volume, whereas many other single-lidar-based wind retrieval techniques rely on assumptions of horizontal flow homogeneity to combine measurements obtained at different locations. This study investigates whether the requirement for intersecting range gates can be relaxed in offshore environments and whether non-collocated dual-Doppler reconstructions can provide useful information on spatial variability. A four-month offshore measurement campaign was conducted near Blyth, UK, using three scanning lidars and an offshore meteorological mast. Collocated DSL reconstructions at ranges of 5–7 km were first validated against cup-anemometer to establish a baseline uncertainty. Subsequently, synchronized range gates with horizontal separations of 500, 1000, and 1500 m were used to quantify the impact of non-collocation on reconstructed wind statistics. The observed deviations were further analyzed using a large-eddy simulation case study. The collocated configuration provided accurate wind speed estimates and TI biases within ±0.01. For wind speeds up to 9 ms−1, non-collocated reconstructions with separations up to 500 m produced uncertainties comparable to the baseline TI measurement uncertainty. Larger separations resulted in increasing deviations, particularly in heterogeneous flow conditions influenced by coastal transitions and wind turbines. Comparison with LES demonstrated that these deviations reflect physically meaningful spatial variability rather than measurement artifacts. The results indicate that strict range-gate intersection is not always required for offshore dual-Doppler reconstruction. Under sufficiently homogeneous offshore conditions, moderate beam separations can be tolerated, while the resulting deviations provide a practical measure of spatial uncertainty relevant for wind resource assessment and load analysis.
Competing interests: At least one of the (co-)authors is a member of the editorial board of Wind Energy Science.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
