Algorithm for Sea Surface Wind Retrieval From TerraSAR-X and TanDEM-X Data

A geophysical model function (GMF), which is denoted by XMOD2, is developed to retrieve sea surface wind field from X-band TerraSAR-X/TanDEM-X (TS-X/TD-X) data. In contrast to the previously developed XMOD1, XMOD2 consists of a nonlinear GMF, and thus, it depicts the difference between upwind and downwind of the sea surface backscatter in X-band synthetic aperture radar (SAR) imagery. By exploiting 371 collocations with in situ buoy measurements that are used as the tuning data set together with analysis wind model results, the retrieved TS-X/TD-X sea surface wind speed using XMOD2 shows a close agreement with buoy measurements with a bias of -0.32 m/s, a root-mean-square error (RMSE) of 1.44 m/s, and a scatter index (SI) of 16.0%. Further validation using an independent data set of 52 cases shows a bias of -0.17 m/s, an RMSE of 1.48 m/s, and an SI of 17.0% comparing with buoy measurements. To apply XMOD2 to TS-X/TD-X data acquired at HH polarization, we validate three X-band SAR polarization ratio models that were tuned using TS-X dual-polarization data by comparing the retrieved sea surface wind speed with buoy measurements.

[1]  Alexis Mouche,et al.  Dual-polarization measurements at C-band over the ocean: results from airborne radar observations and comparison with ENVISAT ASAR data , 2005, IEEE Transactions on Geoscience and Remote Sensing.

[2]  H. Masuko,et al.  Measurement of microwave backscattering signatures of the ocean surface using X band and Ka band airborne scatterometers , 1986 .

[3]  Charlotte Bay Hasager,et al.  Wake effects of large offshore wind farms identified from satellite SAR , 2005 .

[4]  H. Hersbach,et al.  An improved C-band scatterometer ocean geophysical model function: CMOD5 , 2007 .

[5]  Yijun He,et al.  Wind speed retrieval from RADARSAT-2 quad-polarization images using a new polarization ratio model , 2011 .

[6]  Masanobu Shimada,et al.  An L-Band Ocean Geophysical Model Function Derived From PALSAR , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[7]  Marcos Portabella,et al.  On Scatterometer Ocean Stress , 2009 .

[8]  J. Horstmann,et al.  Comparison of high‐resolution wind fields extracted from TerraSAR‐X SAR imagery with predictions from the WRF mesoscale model , 2012 .

[9]  J. Peixoto,et al.  Physics of climate , 1992 .

[10]  Weizeng Shao,et al.  Study on polarisation ratio for X-band using dual-polarisation Terra-SAR X image , 2012, 2012 IEEE International Geoscience and Remote Sensing Symposium.

[11]  David L. T. Anderson,et al.  Scatterometer Data Interpretation: Measurement Space and Inversion , 1997 .

[12]  W. Timothy Liu,et al.  Equivalent Neutral Wind , 1996 .

[13]  M. He,et al.  An algorithm for the retrieval of sea surface wind fields using X-band TerraSAR-X data , 2012 .

[14]  M. Gade,et al.  Investigation of multifrequency/multipolarization radar signatures of rain cells over the ocean using SIR‐C/X‐SAR data , 1998 .

[15]  K. Katsaros,et al.  Observation of tropical cyclones by high-resolution scatterometry , 1998 .

[16]  Carl A. Mears,et al.  Comparison of Special Sensor Microwave Imager and buoy‐measured wind speeds from 1987 to 1997 , 2001 .

[17]  David L. T. Anderson,et al.  Scatterometer data interpretation: Estimation and validation of the transfer function CMOD4 , 1997 .

[18]  D. R. Thompson,et al.  Polarization ratio for microwave backscattering from the ocean surface at low to moderate incidence angles , 1998, IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174).

[19]  Pablo Clemente-Colon,et al.  Comparison of SAR-derived wind speed with model predictions and ocean buoy measurements , 2001, IEEE Trans. Geosci. Remote. Sens..

[20]  Jochen Horstmann,et al.  Wind retrieval over the ocean using synthetic aperture radar with C-band HH polarization , 2000, IEEE Trans. Geosci. Remote. Sens..

[21]  Marco Schwerdt,et al.  Calibration of the TerraSAR-X and the TanDEM-X satellite for the TerraSAR-X mission , 2012 .

[22]  Marco Schwerdt,et al.  Final TerraSAR-X Calibration Results Based on Novel Efficient Methods , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[23]  Xiaofeng Li,et al.  Coastal upwelling observed by multi-satellite sensors , 2009 .

[24]  Jochen Horstmann,et al.  High-resolution mapping of Bora winds in the northern Adriatic Sea using synthetic aperture radar , 2010 .

[25]  Helko Breit,et al.  TerraSAR-X Ground Segment Basic Product Specification Document , 2008 .

[26]  S. Lehner,et al.  Mesoscale wind measurements using recalibrated ERS SAR images , 1998 .

[27]  P. Vachon,et al.  Wind Retrieval from RADARSAT SAR Images: Selection of a Suitable C-Band HH Polarization Wind Retrieval Model , 2000 .

[28]  Hans Hersbach,et al.  554 CMOD 5 . N : A C-band geophysical model function for equivalent neutral wind , 2022 .

[29]  A. Monahan The Probability Distribution of Sea Surface Wind Speeds. Part I: Theory and SeaWinds Observations , 2006 .

[30]  Michael H. Freilich,et al.  Scatterometer-Based Assessment of 10-m Wind Analyses from the Operational ECMWF and NCEP Numerical Weather Prediction Models , 2005 .

[31]  Xiaofeng Li,et al.  Coastal katabatic winds imaged by SAR , 2007 .

[32]  Frank J. Wentz,et al.  A model function for the ocean‐normalized radar cross section at 14 GHz derived from NSCAT observations , 1999 .

[33]  T. Koh,et al.  A diagnostic suite to assess NWP performance , 2012 .