Electromagnetic scattering from large steady breaking waves

被引：17

作者：

Coakley, DB ^{[1
]}

Haldeman, PM ^{[1
]}

Morgan, DG ^{[1
]}

Nicolas, KR ^{[1
]}

Penndorf, DR ^{[1
]}

Wetzel, LB ^{[1
]}

Weller, CS ^{[1
]}

机构：

[1] Thomas Jefferson High Sch Sci & Technol, Alexandria, VA 22312 USA

来源：

EXPERIMENTS IN FLUIDS | 2001年 / 30卷 / 05期

关键词：

D O I：

10.1007/s003480000220

中图分类号：

TH [机械、仪表工业];

学科分类号：

0802 ;

摘要：

A submerged hydrofoil generated large steady breaking waves of 0.3 m and 0.4 m height in a circulating water channel. We measured water fraction in the breakers with conductivity probes. We observed the radar cross-section of the breakers at X-band with a pulsed step-frequency instrumentation radar with high spatial resolution in the downstream direction. The normalized radar cross-section increases with increasing elevation angle of observation for both vertical and horizontal polarization. This variation is consistent with a simple interpretation of the breaking wave as a diffuse (Lambertian) surface. However, the observed sizes and shapes of fluid elements in the breakers clearly show that construction of a theory for electromagnetic scattering from first principles will be challenging. We also obtained the velocity spectrum of the scattering features within the breakers. This spectrum indicates that slower moving small liquid elements rather than the faster moving large disturbances are responsible for most of the electromagnetic scattering.

引用

页码：479 / 487

页数：9

共 17 条

[1] ON THE MICROWAVE REFLECTIVITY OF SMALL-SCALE BREAKING WATER-WAVES [J].

BANNER, ML ;

FOOKS, EH .

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1985, 399 (1816) :93-109

[2]

COAKLEY DB, 1996, 21 NAV HYDR S TRONDH

[3]

COAKLEY DB, 1997, THESIS U MARYLAND CO

[4] Surface ripples due to steady breaking waves [J].

Duncan, JH ;

Dimas, AA .

JOURNAL OF FLUID MECHANICS, 1996, 329 :309-339

[5] Radar backscatter from stationary breaking waves [J].

Ericson, EA ;

Lyzenga, DR ;

Walker, DT .

JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 1999, 104 (C12) :29679-29695

[6] FREQUENCY DEPENDENCE OF THE PROPERTIES OF SEA ECHO [J].

GOLDSTEIN, H .

PHYSICAL REVIEW, 1946, 70 (11-1) :938-946

[7]

MOORE RK, 1990, RADAR HDB, pCH12

[8] Radar imaging of water surface flow fields [J].

Nicolas, KR ;

Lindenmuth, WT ;

Weller, CS ;

Anthony, DG .

EXPERIMENTS IN FLUIDS, 1997, 23 (01) :14-19

[9]

PIERSON WJ, 1990, SURFACE WAVES FLUXES, pCH13

[10] AN ULTRAWIDEBAND, POLARIMETRIC RADAR FOR THE STUDY OF SEA SCATTER [J].

SLETTEN, MA ;

TRIZNA, DB .

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 1994, 42 (11) :1461-1466

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