{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T17:54:14Z","timestamp":1774979654744,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2011,1,11]],"date-time":"2011-01-11T00:00:00Z","timestamp":1294704000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Ocean winds in the Baltic Sea are expected to power many wind farms in the coming years. This study examines satellite Synthetic Aperture Radar (SAR) images from Envisat ASAR for mapping wind resources with high spatial resolution. Around 900 collocated pairs of wind speed from SAR wind maps and from 10 meteorological masts, established specifically for wind energy in the study area, are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a root mean square error of 1.17 m s\u22121, bias of \u22120.25 m s\u22121, standard deviation of 1.88 m s\u22121 and correlation coefficient of R2 0.783. Wind directions from a global atmospheric model, interpolated in time and space, are used as input to the geophysical model function CMOD-5 for SAR wind retrieval. Wind directions compared to mast observations show a root mean square error of 6.29\u00b0 with a bias of 7.75\u00b0, standard deviation of 20.11\u00b0 and R2 of 0.950. The scale and shape parameters, A and k, respectively, from the Weibull probability density function are compared at only one available mast and the results deviate ~2% for A but ~16% for k. Maps of A and k, and wind power density based on more than 1000 satellite images show wind power density values to range from 300 to 800 W m\u22122 for the 14 existing and 42 planned wind farms.\r\n\t\t\t\t\t\t\t\t\t\t\t <\/jats:p>","DOI":"10.3390\/rs3010117","type":"journal-article","created":{"date-parts":[[2011,1,12]],"date-time":"2011-01-12T04:53:33Z","timestamp":1294808013000},"page":"117-144","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":97,"title":["SAR-Based Wind Resource Statistics in the Baltic Sea"],"prefix":"10.3390","volume":"3","author":[{"given":"Charlotte B.","family":"Hasager","sequence":"first","affiliation":[{"name":"Wind Energy Division, Ris\u00f8 DTU, Frederiksborgvej 399, 4000 Roskilde, Denmark"}]},{"given":"Merete","family":"Badger","sequence":"additional","affiliation":[{"name":"Wind Energy Division, Ris\u00f8 DTU, Frederiksborgvej 399, 4000 Roskilde, Denmark"}]},{"given":"Alfredo","family":"Pe\u00f1a","sequence":"additional","affiliation":[{"name":"Wind Energy Division, Ris\u00f8 DTU, Frederiksborgvej 399, 4000 Roskilde, Denmark"}]},{"given":"Xiaoli G.","family":"Lars\u00e9n","sequence":"additional","affiliation":[{"name":"Wind Energy Division, Ris\u00f8 DTU, Frederiksborgvej 399, 4000 Roskilde, Denmark"}]},{"given":"Ferhat","family":"Bing\u00f6l","sequence":"additional","affiliation":[{"name":"Wind Energy Division, Ris\u00f8 DTU, Frederiksborgvej 399, 4000 Roskilde, Denmark"}]}],"member":"1968","published-online":{"date-parts":[[2011,1,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1007\/s10236-004-0098-3","article-title":"Ocean wind fields retrieved from the advanced synthetic aperture radar aboard ENVISAT","volume":"54","author":"Horstmann","year":"2004","journal-title":"Ocean Dyn."},{"key":"ref_2","first-page":"102","article-title":"Ocean wind field mapping from synthetic aperture radar and its application to research and applied problems","volume":"26","author":"Monaldo","year":"2005","journal-title":"Johns Hopkins Apl. Tech. Dig."},{"key":"ref_3","unstructured":"Kerbaol, V. (2008, January January). Near-Real Time Generation of ENVISAT ASAR Level-2 Wind and Waves Products: Presentation of the System and Preliminary Achievements. Proceedings of SEASAR 2008\u20142nd International Workshop on Advances on SAR Oceanography from ENVISAT and ERS Missions, Rome, Italy."},{"key":"ref_4","unstructured":"Kerbaol, V. (2007, January April). Improved Bayesian Wind Vector Retrieval Scheme Using ENVISAT ASAR Data: Principles and Validation Results. Proceedings of ENVISAT Symposium 2007, Montreux, Switzerland. ESA-SP-636."},{"key":"ref_5","unstructured":"Monaldo, F., Kerbaol, V., Clemente-Col\u00f3n, P., Furevik, B., Horstmann, J., Johannessen, J., Li, X., Pichel, W., Sikora, T.D., Thomson, D.J., and Wackerman, C. (2003, January September). The SAR Measurement of Ocean surface Winds: An Overview. Proceedings of the Second Workshop Coastal and Marine Applications of SAR, Svalbard, Norway."},{"key":"ref_6","unstructured":"Beal, R.C., Young, G.S., Monaldo, F., Thompson, D.R., Winstead, N.S., and Schott, C.A. (2005). High Resolution Wind Monitoring with Wide Swath SAR: A User\u2019s Guide."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1781","DOI":"10.1080\/014311600209733","article-title":"Wind energy mapping of coastal zones by synthetic aperture radar (SAR) for siting potential windmill locations","volume":"21","author":"Johannessen","year":"2000","journal-title":"Int. J. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.rse.2006.06.005","article-title":"Wind resource assessment from C-band SAR","volume":"105","author":"Christiansen","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1002\/we.190","article-title":"Quantifying offshore wind resources from satellite wind maps: Study area the North Sea","volume":"9","author":"Hasager","year":"2006","journal-title":"Wind Energy"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Badger, M., Badger, J., Nielsen, M., Hasager, C.B., and Pe\u00f1a, A. (2010). Wind class sampling of satellite SAR imagery for offshore wind resource mapping. J. Appl. Meteorol. Climatol., (in press).","DOI":"10.1175\/2010JAMC2523.1"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/j.rse.2005.07.009","article-title":"Wake effects of large offshore wind farms identified from satellite SAR","volume":"98","author":"Christiansen","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1002\/we.337","article-title":"Wind climate from the regional climate model REMO","volume":"13","author":"Mann","year":"2010","journal-title":"Wind Energy"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Lars\u00e9n, X.G., LARSEN, S.E., and Badger, M. (2010). A case study of mesoscale spectra of wind and temperature, observed and simulated. Q.J.R.Meteorol. Soc., 137.","DOI":"10.1002\/qj.739"},{"key":"ref_14","unstructured":"Horstmann, J., and Koch, W. (2004, January September). Evaluation of an Operational SAR Wind Field Retrieval Algorithm for ENVISAT ASAR. Proceedings of 2004 IEEE International Geoscience and Remote Sensing Symposium, Anchorage, AK, USA."},{"key":"ref_15","unstructured":"Niclos, R., and Caselles, V. (2008). Ocean Remote Sensing: Recent Techniques and Applications, Research Singpost."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1109\/JSTARS.2008.2002218","article-title":"Remote sensing observation used in offshore wind energy","volume":"1","author":"Hasager","year":"2008","journal-title":"IEEE J. Sel. Topics Appl. Earth Obs. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"C03006","DOI":"10.1029\/2006JC003743","article-title":"An improved C-band scatterometer ocean geophysical model function: CMOD5","volume":"112","author":"Hersbach","year":"2007","journal-title":"J. Geophys. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2587","DOI":"10.1109\/36.974994","article-title":"Comparison of SAR-derived wind speed with model predictions and ocean buoy measurements","volume":"39","author":"Monaldo","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1109\/TGRS.2003.817213","article-title":"A systematic comparison of QuickSCAT and SAR ocean surface wind speeds","volume":"42","author":"Monaldo","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"DO09101","DOI":"10.1029\/2009JD012679","article-title":"Estimated global ocean wind power potential from QuikSCAT observations, accounting for turbine characteristics and siting","volume":"115","author":"Capps","year":"2010","journal-title":"J. Geophys. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1007\/BF00118567","article-title":"A note on estimating the effect of a limited fetch on micrometeorological evaporation measurements","volume":"35","author":"Gash","year":"1986","journal-title":"Bound.-Layer Meteorol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3817","DOI":"10.1080\/01431160410001688286","article-title":"Validation of ERS-2 SAR offshore wind-speed maps in the North Sea","volume":"25","author":"Hasager","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_23","unstructured":"Nielsen, M., Astrup, P., Hasager, C.B., Barthelmie, R.J., and Pryor, S.C. (2004). Satellite Information for Wind Energy Applications, Ris\u00f8 National Laboratory. Ris\u00f8-R-1479(EN)."},{"key":"ref_24","unstructured":"Troen, I., and Petersen, E.L. (1989). European Wind Atlas, Ris\u00f8 National Laboratory."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1175\/2096.1","article-title":"Can satellite sampling of offshore wind speeds realistically represent wind speed distributions? Part II Quantifying uncertainties associated with sampling strategy and distribution fitting methods","volume":"43","author":"Pryor","year":"2004","journal-title":"J. Appl. Meteorol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"915","DOI":"10.1175\/1520-0493(1977)105<0915:RODCOO>2.0.CO;2","article-title":"Review of drag coefficients over oceans and continents","volume":"105","author":"Garratt","year":"1977","journal-title":"Month. Weather Rev."},{"key":"ref_27","unstructured":"Antoniou, I., J\u00f8rgensen, H.E., Mikkelsen, T., Frandsen, S., Barthelmie, R., Perstrup, C., and Hurtig, M. (2,, January February). Offshore wind profile measurements from remote sensing instruments. European Wind Energy Conference and Exhibition 2006, Athens, Greece."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1016\/j.jweia.2004.05.005","article-title":"Importance of thermal effects and sea surface roughness for offshore wind resource assessment","volume":"92","author":"Lange","year":"2004","journal-title":"J. Wind Eng. Ind. Aerodyn."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"21049","DOI":"10.1029\/97JC01070","article-title":"The turbulence regime of a very stable marine airflow with quasi-frictional decoupling","volume":"102","author":"Smedman","year":"1997","journal-title":"J. Geophys. Res."},{"key":"ref_30","unstructured":"Mortensen, N., Heathfield, D.N., Landberg, L., Rathmann, O., TROEN, I., and Petersen, E.L. (2000). Wind Atlas Analysis and Wind Atlas Analysis and Application Program: WAsP 7.0 Help Facility, Ris\u00f8 National Laboratory."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"702","DOI":"10.1109\/TGRS.2003.818811","article-title":"Directional analysis of SAR images aiming at wind direction","volume":"42","author":"Koch","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5767","DOI":"10.1029\/96JC02860","article-title":"Scatterometer data interpretation: Estimation and validation of the transfer fuction CMOD4","volume":"102","author":"Stoffelen","year":"1997","journal-title":"J. Geophys. Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1260\/030952407784079762","article-title":"Offshore coastal wind speed gradients: Issues for the design and development of large offshore windfarms","volume":"31","author":"Barthelmie","year":"2007","journal-title":"Wind Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1061\/(ASCE)0733-9402(2006)132:3(91)","article-title":"Challenges in predicting power output from offshore wind","volume":"132","author":"Barthelmie","year":"2006","journal-title":"J. Energy Eng."},{"key":"ref_35","unstructured":"Barthelmie, R., Courtney, M., and Nielsen, M. (1998). The Wind Resource at Middelgrunden, Ris\u00f8 National Laboratoy."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/S0167-6105(01)00195-7","article-title":"Statistical analysis of flow characteristics in the coastal zone","volume":"90","author":"Pryor","year":"2002","journal-title":"J. Wind Eng. Ind. Aerodyn."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1002\/we.196","article-title":"Using airborne and satellite SAR for wake mapping offshore","volume":"9","author":"Christiansen","year":"2006","journal-title":"Wind Energy"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Sathe, A., Gryning, S.-E., and Pe\u00f1a, A. (2010). Comparison of the Atmospheric Stability and Wind Profile Climatology at two Wind Farm Sites over a long marine fetch in the North Sea. Wind Energy, (in review).","DOI":"10.1002\/we.456"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1002\/we.283","article-title":"Offshore wind profiling using light detection and ranging measurements","volume":"12","author":"Hasager","year":"2009","journal-title":"Wind Energy"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1007\/s10546-008-9285-y","article-title":"Charnock\u2019s roughness length model and non-dimensional wind profiles over the sea","volume":"128","author":"Gryning","year":"2008","journal-title":"Bound.-Layer Meteorol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1007\/s10546-008-9323-9","article-title":"Measurements and modelling of the wind speed profile in the marine atmospheric boundary layer","volume":"129","author":"Gryning","year":"2008","journal-title":"Bound.-Layer Meteorol."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/3\/1\/117\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:54:50Z","timestamp":1760219690000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/3\/1\/117"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,1,11]]},"references-count":41,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2011,1]]}},"alternative-id":["rs3010117"],"URL":"https:\/\/doi.org\/10.3390\/rs3010117","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2011,1,11]]}}}