Sea Surface Wind Speed Inversion Using the Low Incident NRCS Measured by TRMM Precipitation Radar

As the launch of radars that observe the ocean at low incident angles, such as the Precipitation Radar (PR) on Tropical Rainfall Measuring Mission (TRMM) satellite and the Surface Wave Investigation and Monitoring (SWIM) on China France Oceanography SATellite, more and more normalized radar cross sections (NRCS) σ0 of ocean surface in low incident angles are obtained. In this paper, the ocean surface NRCS of PR, when there are no rain, are used for wind speed retrieve. The sea surface wind speeds are retrieved by the Maximum Likelihood Estimate. First, the data preprocessing and wind speed inversion method of PR 2A21 data are introduced. In order to improve the inversion accuracy, the empirical GMF at low incident angle is established, using the PR NRCS and QuikScat wind speed. The accuracy of retrieved wind speed is analyzed by comparing it with the buoy, Advanced Scatterometer (ASCAT), and QuikScat. The retrieved wind speeds have a standard deviation of about 1.5 m/s when compared with the buoy, and a standard deviation of 1.1 m/s when compared with ASCAT. The year averaged global wind speed maps of PR as also calculated and compared with that of QuikScat, ASCAT, and TRMM Microwave Imager. Their spatial structures of wind speed are very consistent and correlation coefficient is greater than 0.99. At last, the standard deviation and bias of retrieved wind speeds versus incident angles and wind speeds are also analyzed.

[1]  C. Winn,et al.  SeaWinds on QuikSCAT: sensor description and mission overview , 2000, IGARSS 2000. IEEE 2000 International Geoscience and Remote Sensing Symposium. Taking the Pulse of the Planet: The Role of Remote Sensing in Managing the Environment. Proceedings (Cat. No.00CH37120).

[2]  Jeffrey A. Jones,et al.  Use of the Surface Reference Technique for Path Attenuation Estimates from the TRMM Precipitation Radar , 2000 .

[3]  J. Wilson,et al.  ASCAT – Metop’s Advanced Scatterometer , 2000 .

[4]  Fuk K. Li,et al.  A comparative study of several wind estimation algorithms for spaceborne scatterometers , 1988 .

[5]  G. Valenzuela.  Theories for the interaction of electromagnetic and oceanic waves — A review , 1978 .

[6]  Yijun He,et al.  Asymmetry and Anisotropy of Microwave Backscatter at Low Incidence Angles , 2012, IEEE Transactions on Geoscience and Remote Sensing.

[7]  H. Kuroiwa,et al.  Precipitation radar onboard TRMM satellite , 1996, Proceedings of International Symposium on Phased Array Systems and Technology.

[8]  C. Cox.  Statistics of the sea surface derived from sun glitter , 1954 .

[9]  William J. Plant,et al.  The normalized radar cross section of the sea at 10° incidence , 2000, IEEE Trans. Geosci. Remote. Sens..

[10]  D. Barrick,et al.  Wind dependence of quasi-specular microwave sea scatter , 1974 .

[11]  Donald E. Barrick.  Wind Dependence of QuasiSpecular Scatter Microwave Sea , 1974 .

[12]  Katsuhiko Nishikawa,et al.  Development of precipitation radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite , 2001, IEEE Trans. Geosci. Remote. Sens..

[13]  T. N. Krishnamurti,et al.  The status of the tropical rainfall measuring mission (TRMM) after two years in orbit , 2000 .

[14]  David R. Boggs,et al.  The SASS^{1} scattering coefficient σ ° algorithm , 1980 .

[15]  Michael H. Freilich,et al.  The relationship between winds, surface roughness, and radar backscatter at low incidence angles from TRMM precipitation radar measurements , 2003 .

[16]  Laurent Rey,et al.  SWIMSAT: A Real-Aperture Radar to Measure Directional Spectra of Ocean Waves from Space—Main Characteristics and Performance Simulation , 2001 .

[17]  Gary S. Brown,et al.  Quasi-Specular Scattering from the Air-Sea Interface , 1990 .

[18]  David G. Long,et al.  Spaceborne radar measurement of wind velocity over the ocean-an overview of the NSCAT scatterometer system , 1991, Proc. IEEE.

[19]  Jacques Richard,et al.  SWIM: A Multi-Incidence Beams Ku-band Real Aperture Radar for the Observation of the Ocean Wave Field Spectra , 2008, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium.

[20]  J. Apel.  An improved model of the ocean surface wave vector spectrum and its effects on radar backscatter , 1994 .

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

[22]  A.K. Fung,et al.  Radar determination of winds at sea , 1979, Proceedings of the IEEE.

[23]  David G. Long,et al.  Improved resolution backscatter measurements with the SeaWinds pencil-beam scatterometer , 2000, IEEE Trans. Geosci. Remote. Sens..

[24]  H. Freitag,et al.  Calibration procedures and instrumental accuracies for ATLAS wind measurements , 2001 .

[25]  M. Drinkwater,et al.  The advanced scatterometer (ASCAT) on the meteorological operational (MetOp) platform: A follow on for European wind scatterometers , 2002 .

[26]  Li Li,et al.  Retrieving ocean surface wind speed from the TRMM Precipitation Radar measurements , 2004, IEEE Transactions on Geoscience and Remote Sensing.