Gutierrez, M.; Tiana-Alsina, J.; Rocadenbosch, F.; Sospedra, J.; Aghabi, R.; González-Marco, D. IEEE International Geoscience and Remote Sensing Symposium p. 1607-1610 DOI: 10.1109/IGARSS.2017.8127280 Data de presentació: 2017-07-25 Presentació treball a congrés
This paper presents the development of a new commercial floating lidar system aimed to measure the wind resource and other environmental variables at candidate wind farm locations. This work describes this new lidar system along with the pilot validation trial (IJmuiden, North Sea) carried out. The two main algorithms developed to correct and qualify wind data to fulfill Key Performance Indicators (KPIs) of wind industry are also presented. The two data-processing algorithms are: homodyne wind-direction correction and outlier data filtering. Finally, results of this pilot validation trial are discussed, showing fulfillment of the wind industry requirements for acceptance of commercial floating lidars.
Tiana-Alsina, J.; Rocadenbosch, F.; Gutierrez, M. IEEE International Geoscience and Remote Sensing Symposium p. 1614-1617 DOI: 10.1109/IGARSS.2017.8127282 Data de presentació: 2017-07-25 Presentació treball a congrés
This works presents a simplified Vertical Azimuth Display (VAD) motion simulator for off-shore wind lidars. The simulator is rooted to the case of a conically-scanning lidar (e.g., the Zephyr lidar), where the wind speed vector is retrieved from the Line-of-Sight velocities over one scan period. The methodological part addresses the geometrical foundations of the simulator and how the lidar attitude is assimilated in matrix form. The discussion part considers the case of time-invariant, horizontally-homogeneous wind under two motional cases of the lidar, static and dynamic. Cases examples are parameterized by Horizontal Wind Speed, Wind Direction and tilt amplitude.
This work provides a signal-processing and statistical-error analysis methodology to assess key performance indicators for a floating Doppler wind lidar. The study introduces the raw-to-clean data processing chain, error assessment indicators and key performance indicators, as well as two filtering methods at post-processing level to alleviate the impact of angular motion and spatial variability of the wind flow on the performance indicators. Towards this aim, the study mainly revisits horizontal wind speed (HWS) and turbulence intensity measurements with a floating ZephIR 300 lidar buoy during a 38 day nearshore test campaign in Pont del Petroli (Barcelona). Typical day cases along with overall statistics for the whole campaign are discussed to illustrate the methodology and processing tools developed.
Tiana-Alsina, J.; Gutierrez, M.; Würth, I.; Puigdefabregas, J.; Rocadenbosch, F. IEEE International Geoscience and Remote Sensing Symposium p. 5379-5382 DOI: 10.1109/IGARSS.2015.7327051 Data de presentació: 2015-07-31 Presentació treball a congrés
This paper addresses a cardanic frame as mechanical-compensation device for a Doppler-wind lidar installed on a floating sea buoy as the “moving” lidar. From the methodological point of view, the horizontal wind speed (HWS) measured by both a reference lidar (i.e., “fixed”) and a floating lidar (i.e., “moving”) with and without a cardarnic frame is cross-examined by using standard statistical indicators and a compound pendulum model. Performance results are analysed both at laboratory level using a pitch/roll motion-simulation platform and at a sea-test measurement-campaign level some 250-m offshore Barcelona coast. Finally, simulations of the proposed pendulum-based model enables to tune-in and optimize cardanic-frame design parameters.
Gutierrez, M.; Tiana-Alsina, J.; Bischoff, O.; Cateura, J.; Rocadenbosch, F. IEEE International Geoscience and Remote Sensing Symposium p. 2147-2150 DOI: 10.1109/IGARSS.2015.7326228 Data de presentació: 2015-07-28 Presentació treball a congrés
This paper departs from a preliminary near-shore measurement test campaign hold at El Pont del Petroli (PdP), Barcelona (Spain) where measurements from a Doppler wind-lidar buoy (the ”floating” lidar) are cross-examined against an on-shore reference lidar. From this framework the methodological analysis to intercompare two such lidars in terms of the retrieved Horizontal Wind Speed (HWS) - as key variable - is presented along with an overview of the signal-processing block diagram. Central to this work is to introduce the main error indicators (e.g., bias, RMSE, determination coefficient, absolute error and scatter plots) used to assess the performance of the floating lidar in the campaign. Finally, it is shown that even a basic smoothing procedure on the retrieved 1-s HWS time series is enough to enhance the determination coefficient against the reference lidar Turbulence Intensity (TI).