scholarly journals GF-3 SAR Ocean Wind Retrieval: The First View and Preliminary Assessment

2017 ◽  
Vol 9 (7) ◽  
pp. 694 ◽  
Author(s):  
He Wang ◽  
Jingsong Yang ◽  
Alexis Mouche ◽  
Weizeng Shao ◽  
Jianhua Zhu ◽  
...  
2020 ◽  
Vol 5 (1) ◽  
pp. 375-390 ◽  
Author(s):  
Charlotte B. Hasager ◽  
Andrea N. Hahmann ◽  
Tobias Ahsbahs ◽  
Ioanna Karagali ◽  
Tija Sile ◽  
...  

Abstract. Europe's offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of synthetic aperture radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced Scatterometer (ASCAT) ocean wind maps. The wind statistics at 10 and 100 m above mean sea level (a.m.s.l.) height using an extrapolation procedure involving simulated long-term stability over oceans are presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid spacing with data every 30 min for 30 years from 1989 to 2018, while ASCAT has 12.5 km and SAR has 2 km grid spacing. Offshore mean wind speed maps at 100 m a.m.s.l. height from ASCAT, SAR, WRF and ERA5 at a European scale are compared. A case study on offshore winds near Crete compares SAR and WRF for flow from the north, west and all directions. The paper highlights the ability of the WRF model to simulate the overall European wind climatology and the near-coastal winds constrained by the resolution of the coastal topography in the WRF model simulations.


2019 ◽  
Vol 57 (9) ◽  
pp. 6986-6995
Author(s):  
Vegard Nilsen ◽  
Geir Engen ◽  
Harald Johnsen

2018 ◽  
Vol 10 (12) ◽  
pp. 1938 ◽  
Author(s):  
Tianqi Sun ◽  
Guosheng Zhang ◽  
William Perrie ◽  
Biao Zhang ◽  
Changlong Guan ◽  
...  

We propose two new ocean wind retrieval models for right circular-vertical (RV) and right circular-horizontal (RH) polarizations respectively from the compact-polarimetry (CP) mode of the RADARSAT Constellation Mission (RCM), which is scheduled to be launched in 2019. For compact RV-polarization (right circular transmit and vertical receive), we build the wind retrieval model (denoted CoVe-Pol model) by employing the geophysical model function (GMF) framework and a sensitivity analysis. For compact RH polarization (right circular transmit and horizontal receive), we build the wind retrieval model (denoted the CoHo-Pol model) by using a quadratic function to describe the relationship between wind speed and RH-polarized normalized radar cross-sections (NRCSs) along with radar incidence angles. The parameters of the two retrieval models are derived from a database including wind vectors measured by in situ National Data Buoy Center (NDBC) buoys and simulated RV- and RH-polarized NRCSs and incidence angles. The RV- and RH-polarized NRCSs are generated by a RCM simulator using C-band RADARSAT-2 quad-polarized synthetic aperture radar (SAR) images. Our results show that the two new RCM CP models, CoVe-Pol and CoHo-POL, can provide efficient methodologies for wind retrieval.


2019 ◽  
Vol 57 (9) ◽  
pp. 7075-7085 ◽  
Author(s):  
Lin Ren ◽  
Jingsong Yang ◽  
Alexis A. Mouche ◽  
He Wang ◽  
Gang Zheng ◽  
...  

2019 ◽  
Vol 16 (9) ◽  
pp. 1398-1401 ◽  
Author(s):  
Guosheng Zhang ◽  
Biao Zhang ◽  
William Perrie ◽  
Yijun He ◽  
Haiyan Li ◽  
...  

2019 ◽  
Author(s):  
Charlotte B. Hasager ◽  
Andrea N. Hahmann ◽  
Tobias Ahsbahs ◽  
Ioanna Karagali ◽  
Tija Sile ◽  
...  

Abstract. Europe’s offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of Synthetic Aperture Radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced SCATterometer (ASCAT) ocean wind maps. The wind statistics at 10m and 100m height using an extrapolation procedure involving simulated long-term stability over oceans is presented for both SAR and ASCAT. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented. This has 3 km grid resolution with data every 30 minutes during 30 years from 1989 to 2018, while ASCAT has 12.5 km and SAR has 2 km resolution. Offshore mean wind speed maps at 100 m height from ASCAT, SAR, WRF and ERA5 at a European scale are compared. A case study on offshore winds near Crete compares SAR and WRF for flow from north, west and all directions. The paper highlights the ability of the WRF model to simulate the overall European wind climatology and the near coastal winds constrained by the resolution of the coastal topography in the WRF model simulations.


1984 ◽  
Vol 15 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Harriet B. Klein

Formal articulation test responses are often used by the busy clinician as a basis for planning intervention goals. This article describes a 6-step procedure for using efficiently the single-word responses elicited with an articulation test. This procedure involves the assessment of all consonants within a word rather than only test-target consonants. Responses are organized within a Model and Replica chart to yield information about an individual's (a) articulation ability, (b) frequency of target attainment, substitutions, and deletions, (c) variability in production, and (d) phonological processes. This procedure is recommended as a preliminary assessment measure. It is advised that more detailed analysis of continuous speech be undertaken in conjunction with early treatment sessions.


Sign in / Sign up

Export Citation Format

Share Document