High-resolution wind fields from synthetic aperture radars and numerical models for offshore wind farming

2003 ◽  
pp. 450-457
Author(s):  
S. Lehner ◽  
J. Horstmann ◽  
C. Hasager
Keyword(s):  
High Resolution ◽  
Numerical Models ◽  
Offshore Wind ◽  
Synthetic Aperture ◽  
Wind Fields ◽  
Synthetic Aperture Radars

High Resolution Wind Fields Retrieved From Spaceborne Synthetic Aperture Radar Images in Comparison to Numerical Models

2002 ◽  
Author(s):  
Jochen Horstmann ◽  
Wolfgang Koch ◽  
Susanne Lehner
Keyword(s):  
High Resolution ◽  
Wind Speed ◽  
Synthetic Aperture Radar ◽  
Wind Direction ◽  
Numerical Models ◽  
Synthetic Aperture ◽  
Wind Fields ◽  
Coastal Regions ◽  
Radar Images ◽  
Aperture Radar

This paper introduces a recently developed algorithm to retrieve high-resolution wind fields over the ocean surface from spaceborne synthetic aperture radar (SAR) data. The algorithm consists of two parts, the first for determining wind direction and the second for wind speed retrieval. Wind directions are extracted from wind induced streaks e.g. from boundary layer rolls, Langmuir cells, or wind shadowing, which are approximately in line with the mean wind direction. Wind speed is derived from the normalized radar cross section (NRCS) and image geometry of the SAR image, together with the local retrieved wind direction. The application of SAR-wind retrieval in coastal regions is demonstrated using data acquired aboard the European satellites ERS-1 and ERS-2 and the Canadian satellite RADARSAT-1. These data allow to measure wind fields of an area of up to 500 km × 500 km with a resolution of up to 200 m. To improve and validate the set-up of numerical high-resolution models in coastal regions SAR-retrieved wind fields offer an unique opportunity. This is shown by comparisons of wind fields measured by SAR to results of the numerical model REMO, HIRLAM and GESIMA.

Wind Measurements for Optimal Siting, Construction and Operation of Offshore Wind Farms With Synthetic Aperture Radar

2003 ◽  
Author(s):  
Susanne Lehner ◽  
Jochen Horstmann ◽  
Tobias Schneiderhan ◽  
Johannes Schulz-Stellenfleth
Keyword(s):  
High Resolution ◽  
Numerical Models ◽  
Wind Farms ◽  
Offshore Wind ◽  
Wind Fields ◽  
Sar Images ◽  
Offshore Wind Farms ◽  
Radar Sensors ◽  
The North ◽  
The Baltic

In all European countries with shallow coastal waters and strong mean wind speed at the coast the planning and construction of offshore wind farms is on the way and large parts of the North Sea and the Baltic are under investigation as to whether they are suitable for offshore parks. In this paper it is demonstrated how satellite images taken by spaceborne radar sensors can be used to determine mesoscale wind fields and thus help in the task of planning offshore wind farms. High resolution SAR images acquired by the European remote sensing satellite ERS 2 are presented which show single wind turbines (Fig. 1). The derivation of high resolution wind fields from SAR images is explained and comparisons with numerical models are presented.

scholarly journals Modeling Watershed Response in Semiarid Regions With High-Resolution Synthetic Aperture Radars

2014 ◽  
Vol 7 (7) ◽  
pp. 2732-2745 ◽  
Author(s):  
Donato Amitrano ◽  
Fabio Ciervo ◽  
Gerardo Di Martino ◽  
Maria Nicolina Papa ◽  
Antonio Iodice ◽  
...  
Keyword(s):  
High Resolution ◽  
Synthetic Aperture ◽  
Semiarid Regions ◽  
Watershed Response ◽  
Synthetic Aperture Radars

scholarly journals Storm surge in the Adriatic Sea: observational and numerical diagnosis of an extreme event

2006 ◽  
Vol 7 ◽  
pp. 371-378 ◽  
Author(s):  
L. Zampato ◽  
G. Umgiesser ◽  
S. Zecchetto
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Storm Surge ◽  
Hydrodynamic Model ◽  
Adriatic Sea ◽  
Extreme Event ◽  
Numerical Models ◽  
Limited Area ◽  
Wind Fields ◽  
Northern Adriatic

Abstract. Storm surge events occur in the Adriatic Sea, in particular during autumn and winter, often producing flooding in Venice. Sea levels are forecasted by numerical models, which require wind and pressure fields as input. Their performances depend crucially on the quality of those fields. The storm surge event on 16 November 2002 is analysed and simulated through a finite element hydrodynamic model of the Mediterranean Sea. Several runs were carried out, imposing different atmospheric forcings: wind fields from ECMWF analysis, high resolution winds from the limited area model LAMI and satellite observed winds from QuikSCAT (NASA). The performance of the hydrodynamic model in each case has been quantified. ECMWF fields are effective in reproducing the sea level in the northern Adriatic Sea, if the wind speed is enhanced by a suitable multiplying factor. High resolution winds from LAMI give promising results, permitting an accurate simulation of the sea level maxima. QuikSCAT satellite wind fields produce also encouraging results which claim, however, for further research.

scholarly journals Relationship between SAR-Derived Wind Vectors and Wind at 10-m Height Represented by a Mesoscale Model

2006 ◽  
Vol 134 (5) ◽  
pp. 1505-1517 ◽  
Author(s):  
Wolfgang Koch ◽  
Frauke Feser
Keyword(s):  
Wind Speed ◽  
Mesoscale Model ◽  
Numerical Models ◽  
Synthetic Aperture ◽  
Band Model ◽  
Strong Decrease ◽  
Wind Fields ◽  
Sar Images ◽  
Wind Speeds ◽  
Sar Imagery

Abstract Wind vectors over the ocean were extracted from a large number of synthetic aperture radar (SAR) images from the European Remote Sensing Satellites (ERS-1 and ERS-2). The wind directions are inferred from the orientation of wind streaks that are imaged by the SAR, while the wind speeds are retrieved by inversion of the C-band model CMOD4. The derived wind directions and speeds were compared to wind vectors from the numerical Regional Model (REMO) that are available hourly on a 55-km grid. The large number of comparisons and independent weather situations allowed for an analysis of subsets that are classified by SAR-derived wind speed. A strong decrease of the standard deviation of directional differences with increasing wind speed was found. Biases of directional differences depend on SAR wind speed as well. Furthermore, the influence of the temporal difference between SAR overflight and model and an automatic image filtering on the directional error is demonstrated. Overall, reasonable fields of wind vectors were extracted from SAR imagery in 70 of 80 cases. These fields provide valuable information for validation of numerical models of the atmosphere and case studies of coastal wind fields.

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