Study on Comparison Analysis and Error Analysis of Polarization Ratio Models

2013 ◽  
Vol 655-657 ◽  
pp. 735-739
Author(s):  
Ke Wang ◽  
Yuan Zhang ◽  
Yan Bo Hui ◽  
Feng Wang ◽  
Hong Yan Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
Error Analysis ◽  
Wind Field ◽  
Incidence Angle ◽  
Surface Wind ◽  
Comparison Analysis ◽  
Polarization Ratio ◽  
Sar Images ◽  
Ocean Surface Wind ◽  
Surface Wind Field

Polarization ratio models are key problem for ocean surface wind field retrieval from HH polarization SAR images. This paper studied deeply on various polarization ratio models, and carried on comparison analysis and error analysis about them. We analyzed influence of incidence angle, azimuth, and wind speed for polarization ratio. By using true measurement of polarization ratio, we statistically valuated ability of various polarization ratio models, and proposed the best choice of polarization ratio models. Our research has guide meaning for using polarization ratio models reasonably.

scholarly journals A Wind Speed Retrieval Model for Sentinel-1A EW Mode Cross-Polarization Images

2019 ◽  
Vol 11 (2) ◽  
pp. 153 ◽  
Author(s):  
Yuan Gao ◽  
Changlong Guan ◽  
Jian Sun ◽  
Lian Xie
Keyword(s):  
Wind Speed ◽  
Incidence Angle ◽  
Surface Wind ◽  
European Space Agency ◽  
Sea Surface ◽  
Cross Polarization ◽  
Retrieval Model ◽  
Sar Images ◽  
Wind Speeds ◽  
Sea Surface Wind

In contrast to co-polarization (VV or HH) synthetic aperture radar (SAR) images, cross-polarization (CP for VH or HV) SAR images can be used to retrieve sea surface wind speeds larger than 20 m/s without knowing the wind directions. In this paper, a new wind speed retrieval model is proposed for European Space Agency (ESA) Sentinel-1A (S-1A) Extra-Wide swath (EW) mode VH-polarized images. Nineteen S-1A images under tropical cyclone condition observed in the 2016 hurricane season and the matching data from the Soil Moisture Active Passive (SMAP) radiometer are collected and divided into two datasets. The relationships between normalized radar cross-section (NRCS), sea surface wind speed, wind direction and radar incidence angle are analyzed for each sub-band, and an empirical retrieval model is presented. To correct the large biases at the center and at the boundaries of each sub-band, a corrected model with an incidence angle factor is proposed. The new model is validated by comparing the wind speeds retrieved from S-1A images with the wind speeds measured by SMAP. The results suggest that the proposed model can be used to retrieve wind speeds up to 35 m/s for sub-bands 1 to 4 and 25 m/s for sub-band 5.

scholarly journals A new ocean surface wind field retrieval method from C-band airborne synthetic aperture radar

2013 ◽  
Vol 62 (6) ◽  
pp. 068401
Author(s):  
Ai Wei-Hua ◽  
Yan Wei ◽  
Zhao Xian-Bin ◽  
Liu Wen-Jun ◽  
Ma Shuo
Keyword(s):  
Synthetic Aperture Radar ◽  
Wind Field ◽  
Surface Wind ◽  
Ocean Surface ◽  
Synthetic Aperture ◽  
Retrieval Method ◽  
Ocean Surface Wind ◽  
Surface Wind Field ◽  
Aperture Radar

Measuring Ocean Surface Wind Field Using Shipborne High-Frequency Surface Wave Radar

2018 ◽  
Vol 56 (6) ◽  
pp. 3383-3397 ◽  
Author(s):  
Junhao Xie ◽  
Guowei Yao ◽  
Minglei Sun ◽  
Zhenyuan Ji
Keyword(s):  
Surface Wave ◽  
High Frequency ◽  
Wind Field ◽  
Surface Wind ◽  
Ocean Surface ◽  
Wave Radar ◽  
Ocean Surface Wind ◽  
Surface Wind Field

Scaling Feature of the Ocean Surface Wind Field

2021 ◽  
Author(s):  
Yang Gao ◽  
Francois G Schmitt ◽  
Jianyu Hu ◽  
Yongxiang Huang
Keyword(s):  
Seasonal Variations ◽  
Wind Field ◽  
Surface Wind ◽  
Ocean Surface ◽  
Scaling Exponent ◽  
Scaling Exponents ◽  
Multiscale Dynamics ◽  
Ocean Surface Wind ◽  
Scaling Features ◽  
Surface Wind Field

<p>The ocean surface wind plays a crucial role in the air-sea exchanges of momentum, heat, and mass, consequently is vital to the controlling of weather and climate. Due to the extremely large range of scales of the motion of the wind field, e.g., flow structures from millimeters to thousands of kilometers, the multiscale dynamics are known to be relevant. In this work, with the help of a Wiener-Khinchine theorem-based Fourier power spectrum estimator, the scaling features of the wind field provided by several satellites, i.e., QuikSCAT, Metop-A, -B, and -C, Haiyang-2B, and China France Oceanography SATellite (CFOSAT), is examined. Power-law scaling behavior is evident in the ranges of 100 to 3000 km with a scaling exponent β varying from 5/3 to 3. The global distributions and seasonal variations of the scaling exponent β have also been considered. The results show that due to the energetic convective activities in the low-latitude zones, the scaling exponents β in these regions are closer to the value of 5/3. As for the mid-latitudes, the values of β are close to 2 and independent of the variation of longitude. Concerning the seasonal variations, for most regions, the scaling exponents measured in winter are larger than those in summer. Furthermore, the seasonal variations of β in low-latitudes are stronger than those in the mid-latitudes. Our preliminary results indicate that all satellites provide a consistent scaling feature of the ocean surface wind field.</p>

scholarly journals Tip Jets and Barrier Winds: A QuikSCAT Climatology of High Wind Speed Events around Greenland

2005 ◽  
Vol 18 (18) ◽  
pp. 3713-3725 ◽  
Author(s):  
G. W. K. Moore ◽  
I. A. Renfrew
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
Surface Wind ◽  
High Wind ◽  
High Wind Speed ◽  
Wind Speeds ◽  
Daily Sampling ◽  
Seawinds Scatterometer ◽  
High Topography ◽  
Surface Wind Field

Abstract The high topography of Greenland results in a number of orographically induced high wind speed flows along its coast that are of interest from both a severe weather and climate perspective. Here the surface wind field dataset from the NASA–JPL SeaWinds scatterometer on board the Quick Scatterometer (QuikSCAT) satellite is used to develop a wintertime climatology of these flows. The high spatial resolution and the twice-daily sampling of the SeaWinds instrument allows for a much more detailed view of the surface winds around Greenland than has been previously possible. Three phenomena stand out as the most distinctive features of the surface wind field during the winter months: the previously identified tip jets and reverse tip jets, as well as the hitherto unrecognized barrier flows along its southeast coast in the vicinity of the Denmark Strait. Peak surface wind speeds associated with these phenomena can be as large as 50 m s−1 with winds over 25 m s−1 occurring approximately 10%–15% of the time at each location. A compositing technique is used to show that each type of flow is the result of an interaction between a synoptic-scale parent cyclone and the high topography of Greenland. In keeping with previous work, it is argued that tip jets are caused by a combination of conservation of the Bernoulli function during orographic descent and acceleration due to flow splitting as stable air passes around Cape Farewell, while barrier winds are a geostrophic response to stable air being forced against high topography. It is proposed that reverse tip jets occur when barrier winds reach the end of the topographic barrier and move from a geostrophic to a gradient wind balance, becoming supergeostrophic as a result of their anticyclonic curvature.

Development of polarization ratio model for sea surface wind field retrieval from TerraSAR-X HH polarization data

2014 ◽  
Vol 35 (11-12) ◽  
pp. 4046-4063 ◽  
Author(s):  
Weizeng Shao ◽  
Xiao-Ming Li ◽  
Susanne Lehner ◽  
Changlong Guan
Keyword(s):  
Wind Field ◽  
Surface Wind ◽  
Sea Surface ◽  
Ratio Model ◽  
Polarization Ratio ◽  
Polarization Data ◽  
Sea Surface Wind ◽  
Surface Wind Field

Ocean Surface Wind Speed Retrieval From C-Band SAR Images Without Wind Direction Input

2014 ◽  
Vol 52 (2) ◽  
pp. 980-990 ◽  
Author(s):  
Alexander S. Komarov ◽  
Vladimir Zabeline ◽  
David G. Barber
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Surface Wind ◽  
Ocean Surface ◽  
Surface Wind Speed ◽  
Sar Images ◽  
Ocean Surface Wind

Measurements of eddies in the ocean surface wind field by a mix of single and multiple-frequency HF radars on monterey bay california

2007 ◽  
Author(s):  
John F. Vesecky ◽  
Jessica Drake ◽  
Kenneth Laws ◽  
Frank L. Ludwig ◽  
Calvin C. Teague ◽  
...  
Keyword(s):  
Wind Field ◽  
Surface Wind ◽  
Ocean Surface ◽  
Monterey Bay ◽  
Multiple Frequency ◽  
Ocean Surface Wind ◽  
Surface Wind Field
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