Requirement on Antenna Cross-Polarization Isolation for the Operational Use of C-Band SAR Constellations in Maritime Surveillance

2010 ◽  
Vol 7 (4) ◽  
pp. 861-865 ◽  
Author(s):  
R. Touzi ◽  
P. W. Vachon ◽  
J. Wolfe
Keyword(s):  
Cross Polarization ◽  
Maritime Surveillance

scholarly journals DETECTION OF MARINE VESSELS BASED ON VARIATION OF DEGREE OF POLARIZATION

2018 ◽  
Vol IV-5 ◽  
pp. 311-316
Author(s):  
G. K. Dashondhi ◽  
K. M. Buddhiraju
Keyword(s):  
Satellite Images ◽  
Speckle Noise ◽  
Vital Role ◽  
Degree Of Polarization ◽  
False Alarms ◽  
Cross Polarization ◽  
Maritime Surveillance ◽  
L Band ◽  
Sar Imagery ◽  
Marine Vessels

<p><strong>Abstract.</strong> For improving security of any country, satellite images are playing vital role. Vessels detection using SAR imagery is one of the primary requirements for maritime surveillance. In this paper, the algorithm used for vessels detection has four parts. The first part includes pre-processing to reduce speckle noise, second part helps in the reduction of cross polarization by real and complex rotation of the coherency matrix, third part derives a new parameter called variation of degree of polarization (VD) and fourth one is a post processing part to connect region and fill gaps using morphological operation. The proposed algorithm is tested on ALOS PALSAR1 (space borne L band) and UAVSAR (Airborne L band) datasets and yielded promising results with a relatively few false alarms.</p>

A Cross Polarization Suppressed Sequential Array with L-Probe Fed Rectangular Microstrip Antennas

2011 ◽  
Vol E94-B (9) ◽  
pp. 2653-2655
Author(s):  
Kazuki IKEDA ◽  
Keigo SATO ◽  
Ken-ichi KAGOSHIMA ◽  
Shigeki OBOTE ◽  
Atsushi TOMIKI ◽  
...  
Keyword(s):  
Microstrip Antennas ◽  
Cross Polarization

High-Pressure Homogenization Alters Physicochemical Properties and In Vitro Digestibility of Chinese Yam (Dioscorea Opposita Thunb.) Starch

2018 ◽  
Vol 18 (1) ◽  
pp. 10-15
Author(s):  
Wang Yi-Wei ◽  
He Yong-Zhao ◽  
An Feng-Ping ◽  
Huang Qun ◽  
Zeng Feng ◽  
...  
Keyword(s):  
High Pressure ◽  
Physicochemical Properties ◽  
Starch Content ◽  
In Vitro Digestibility ◽  
High Pressure Homogenization ◽  
Starch Granules ◽  
Cross Polarization ◽  
Chinese Yam ◽  
Crystal Type

In this study, Chinese yam starch-water suspension (8%) were subjected to high-pressure homogenization (HPH) at 100 MPa for increasing cycle numbers, and its effect of on the physicochemical properties of the starch was investigated. Results of the polarizing microscope observations showed that the starch granules were disrupted (i.e. greater breakdown value) after HPH treatment, followed by a decrease in cross polarization. After three HPH cycles, the crystallinity of starch decreased, while the crystal type remained unaltered. Meanwhile, the contents of rapidly digestible starch and slowly digestible starch were increased. On the contrary, resistant starch content was decreased. Our results indicate that HPH treatment resulted in reduction of starch crystallinity and increase of starch digestibility.

scholarly journals Simple design of efficient broadband multifunctional polarization converter for X-band applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thi Kim Thu Nguyen ◽  
Thi Minh Nguyen ◽  
Hong Quang Nguyen ◽  
Thanh Nghia Cao ◽  
Dac Tuyen Le ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Incident Angle ◽  
Polarization Conversion ◽  
Simple Design ◽  
Cross Polarization ◽  
Polarization Converter ◽  
Frequency Bands ◽  
X Band ◽  
Cost Efficient ◽  
Patch Resonators

AbstractA simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42–7.6 GHz and 13–13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.

scholarly journals Pulse sequence and sample formulation optimization for dipolar order mediated 1H→13C cross-polarization

2021 ◽  
Vol 23 (15) ◽  
pp. 9457-9465
Author(s):  
Stuart J. Elliott ◽  
Olivier Cala ◽  
Quentin Stern ◽  
Samuel F. Cousin ◽  
Dmitry Eshchenko ◽  
...  
Keyword(s):  
Pulse Sequence ◽  
Cross Polarization ◽  
Diverse Range ◽  
Formulation Optimization ◽  
Dipolar Order

Optimization of a dipolar cross-polarization (dCP) sequence increases the efficiency of 1H polarization transfers to 13C spins in a diverse range of molecular candidates with 13C polarizations surpassing 30%.

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