Research on Wind Speed Inversion Method for X-Band Networked SAR Satellite

Synthetic aperture radar (SAR) can extract sea surface wind speed information. To extract wind speed information through the geophysical model function (GMF), the corresponding wind direction information must be input. This article introduces some concepts about networked SAR satellites. The networked satellites enable multiple SARs to observe the same sea surface at different incidence angles at the same time. Aiming at the X-band networked SAR data with different incident angles, the cost function is established by using the GMF. By minimizing the cost function, accurate wind speed information can be extracted without inputting wind direction information. When the noise is small, the wind direction information is introduced, and the accuracy of the extracted wind speed will be improved. When the noise is less than 1 dB and the incident angle is greater than 30°, the root-mean-square error (RMSE) of the wind speed extracted by this method is basically less than 2 m/s.

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SUITABLE WIND DIRECTION FOR SEA SURFACE WIND SPEED RETRIEVAL USING SYNTHETIC APERTURE RADAR

Journal of Japan Society of Civil Engineers Ser B2 (Coastal Engineering) ◽

10.2208/kaigan.77.2_i_1117 ◽

2021 ◽

Vol 77 (2) ◽

pp. I_1117-I_1122

Author(s):

Ryoya OHKUBO ◽

Yuko TAKEYAMA ◽

Tsuyoshi IKEYA ◽

Teruo OHSAWA

Keyword(s):

Wind Speed ◽

Synthetic Aperture Radar ◽

Wind Direction ◽

Surface Wind ◽

Surface Wind Speed ◽

Sea Surface ◽

Synthetic Aperture ◽

Sea Surface Wind Speed ◽

Sea Surface Wind ◽

Aperture Radar

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Characteristics and Applications of the Ground-Based X Band Low Elevation Angle Brightness Temperatures under Low Sea State Based on Measured Data

Remote Sensing ◽

10.3390/rs12111736 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1736

Author(s):

Zhongqing Cao ◽

Lixin Guo ◽

Shifeng Kang ◽

Xianhai Cheng ◽

Qingliang Li ◽

...

Keyword(s):

Wind Speed ◽

Meteorological Data ◽

Surface Wind ◽

Elevation Angle ◽

Surface Wind Speed ◽

Sea Surface ◽

Sea State ◽

Sea Surface Wind Speed ◽

Sea Surface Wind ◽

X Band

In ground-based microwave radiometer remote sensing, low-elevation-angle (−3°~3°) radiation data are often discarded because they are considered to be of little value and are often difficult to model due to the complicated mechanism. Based on the observed X-band horizontal polarization low elevation angle microwave radiation data and the meteorological data at the same time, this study investigated the generation mechanism of low elevation angle brightness temperature (LEATB) and its relationship with meteorological data, i.e., temperature, humidity, and wind speed, under low sea state. As a result, one could find that the LEATB was sensitive to the atmosphere at the elevation angle between 1° to 3°, and a diurnal variation of the LEATB reached up to 10 K. This study also found a linear relationship between the LEATB and sea surface wind speed under low sea state at an elevation range from −3° to 0°, i.e., the brightness temperature decreased as the wind speed increased, which was inconsistent with the observations at the elevation angle from −10° to −5°. The variation of the LEATB difference according to the change in the over-the-horizon detection capability (OTHDC) of the shipborne microwave radar was examined to identify the reason for this phenomenon theoretically. The results showed that the LEATB difference was significantly influenced by a change in the OTHDC. Further, this study examined a remote sensing method to extract the sea surface wind speed data from experimental LEATB data under low sea state. The results demonstrated that the X-band horizontal polarization LEATBs were useful to retrieve the sea surface wind speed data at a reasonable accuracy—the root mean square error of 0.02408 m/s. Overall, this study proved the promising potential of the LEATB data for retrieving temperature profiles, humidity profiles, sea surface winds, and the OTHDC.

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X-band COSMO-SkyMed wind field retrieval, with application to coastal circulation modeling

Ocean Science ◽

10.5194/os-9-121-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 121-132 ◽

Cited By ~ 16

Author(s):

A. Montuori ◽

P. de Ruggiero ◽

M. Migliaccio ◽

S. Pierini ◽

G. Spezie

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Surface Wind ◽

Circulation Model ◽

Coastal Circulation ◽

Wind Fields ◽

Sea Surface Wind ◽

X Band ◽

Sar Data ◽

Ecmwf Model

Abstract. In this paper, X-band COSMO-SkyMed© synthetic aperture radar (SAR) wind field retrieval is investigated, and the obtained data are used to force a coastal ocean circulation model. The SAR data set consists of 60 X-band Level 1B Multi-Look Ground Detected ScanSAR Huge Region COSMO-SkyMed© SAR data, gathered in the southern Tyrrhenian Sea during the summer and winter seasons of 2010. The SAR-based wind vector field estimation is accomplished by resolving both the SAR-based wind speed and wind direction retrieval problems independently. The sea surface wind speed is retrieved by means of a SAR wind speed algorithm based on the azimuth cut-off procedure, while the sea surface wind direction is provided by means of a SAR wind direction algorithm based on the discrete wavelet transform multi-resolution analysis. The obtained wind fields are compared with ground truth data provided by both ASCAT scatterometer and ECMWF model wind fields. SAR-derived wind vector fields and ECMWF model wind data are used to construct a blended wind product regularly sampled in both space and time, which is then used to force a coastal circulation model of a southern Tyrrhenian coastal area to simulate wind-driven circulation processes. The modeling results show that X-band COSMO-SkyMed© SAR data can be valuable in providing effective wind fields for coastal circulation modeling.

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X-band COSMO-SkyMed wind field retrieval, with application to coastal circulation modeling

Ocean Science Discussions ◽

10.5194/osd-9-3251-2012 ◽

2012 ◽

Vol 9 (5) ◽

pp. 3251-3279 ◽

Cited By ~ 1

Author(s):

A. Montuori ◽

P. de Ruggiero ◽

M. Migliaccio ◽

S. Pierini ◽

G. Spezie

Keyword(s):

Wind Speed ◽

Wind Direction ◽

Surface Wind ◽

Coastal Circulation ◽

Wind Fields ◽

Sea Surface Wind ◽

X Band ◽

Circulation Modeling ◽

Sar Data ◽

Ecmwf Model

Abstract. In this paper, X-band COSMO-SkyMed© SAR wind field retrieval is investigated to force coastal circulation modeling. The SAR data set consists of 60 X-band Level 1B Multi-Look Ground Detected ScanSAR Huge Region COSMO-SkyMed© SAR data, gathered in the Southern Tyrrhenian Sea during the Summer and Winter seasons of 2010. The SAR-based wind vector field estimation is accomplished by resolving both the SAR-based wind speed and wind direction retrieval problems independently. The sea surface wind speed is retrieved by means of a SAR wind speed algorithm based on the Azimuth cut-off procedure, while the sea surface wind direction is provided by means of a SAR wind direction algorithm based on the Discrete Wavelet Transform Multi-Resolution Analysis. The obtained wind fields are compared with ground truth data provided by both ASCAT scatterometer and ECMWF model wind fields. SAR-derived wind vector fields and ECMWF model wind data are used to construct a blended wind product regularly sampled in both space and time, which is then used to force a coastal circulation model of a Southern Tyrrhenian coastal area to simulate wind-driven circulation processes. The modeling results clearly show that X-band COSMO-SkyMed© SAR data can be valuable in providing effective wind fields for coastal circulation modeling.

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Lidar In-space Technology Experiment measurements of sea surface directional reflectance and the link to surface wind speed

Applied Optics ◽

10.1364/ao.37.005550 ◽

1998 ◽

Vol 37 (24) ◽

pp. 5550 ◽

Cited By ~ 24

Author(s):

Robert T. Menzies ◽

David M. Tratt ◽

William H. Hunt

Keyword(s):

Wind Speed ◽

Surface Wind ◽

Surface Wind Speed ◽

Sea Surface ◽

Space Technology ◽

Directional Reflectance

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GPS Reflections for Sea Surface Wind Speed Measurement

IEEE Geoscience and Remote Sensing Letters ◽

10.1109/lgrs.2008.2000620 ◽

2008 ◽

Vol 5 (4) ◽

pp. 569-572 ◽

Cited By ~ 7

Author(s):

D. K. Yang ◽

Y. Q. Zhang ◽

Y. Lu ◽

Q. S. Zhang

Keyword(s):

Wind Speed ◽

Surface Wind ◽

Surface Wind Speed ◽

Sea Surface ◽

Sea Surface Wind Speed ◽

Sea Surface Wind ◽

Speed Measurement ◽

Wind Speed Measurement

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Sea surface wind perturbations over the Kashevarov Bank of the Okhotsk Sea: a satellite study

Annales Geophysicae ◽

10.5194/angeo-29-393-2011 ◽

2011 ◽

Vol 29 (2) ◽

pp. 393-399

Author(s):

T. I. Tarkhova ◽

M. S. Permyakov ◽

E. Yu. Potalova ◽

V. I. Semykin

Keyword(s):

Wind Speed ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Surface Wind ◽

Sea Surface ◽

Cold Spot ◽

Okhotsk Sea ◽

Autumn Period ◽

Sea Surface Wind ◽

Spot Center

Abstract. Sea surface wind perturbations over sea surface temperature (SST) cold anomalies over the Kashevarov Bank (KB) of the Okhotsk Sea are analyzed using satellite (AMSR-E and QuikSCAT) data during the summer-autumn period of 2006–2009. It is shown, that frequency of cases of wind speed decreasing over a cold spot in August–September reaches up to 67%. In the cold spot center SST cold anomalies reached 10.5 °C and wind speed lowered down to ~7 m s−1 relative its value on the periphery. The wind difference between a periphery and a centre of the cold spot is proportional to SST difference with the correlations 0.5 for daily satellite passes data, 0.66 for 3-day mean data and 0.9 for monthly ones. For all types of data the coefficient of proportionality consists of ~0.3 m s−1 on 1 °C.

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