On the synthetic aperture radar imaging of ocean surface waves

Ivanov, A. M.

doi:10.1109/joe.1982.1145517

Cited by 21 publications

(6 citation statements)

References 9 publications

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“…In this expression, U, corresponds to the spatial fluctuations of the cross-section and ut represents the temporal change of U, at a position ( x , y ) on the surface. The present surface model is in good agreement with experiment as shown in a previous paper (Ouchi 1982b) and has been used by various authors (Alpers and Rufenach 1979b, Raney 1980, Ivanov 1982) with different interpretation of the temporal random fluctuations.…”

Section: H ( X Y ; L ) = Hm(x Y ; L) + Hr(x Y ;supporting

confidence: 89%

“…In the limit to+ and for azimuth waves, equation ( 37) is equivalent to the result of Rufenach and Alpers (1981). Similar results have also been obtained by Ivanov (1982). The above image modulation comes from velocity bunching, of which the mechanisms have been studied for mainly azimuth waves.…”

Section: Of Ocean Wavessupporting

confidence: 71%

“…Jain (1978) and Shuchman and Zelenka (1978) consider that the phase velocity of a long wave changes the relative velocity of the radar platform, while Alpers and Rufenach (1979a) and Alpers et a1 (1981) suggest that defocusing is due to the slant-range acceleration associated with the orbital motions of a long wave. Recently, Ivanov (1982), Ouchi (1983) and Rotheram (1983) have independently reached the same conclusion that the amount of defocusing of the reference signal for optimum images depends only on the phase velocity of a long wave and propagation direction.…”

Section: Introductionmentioning

confidence: 88%

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Two-dimensional imaging mechanisms of ocean waves by synthetic aperture radars

Ouchi¹

1984

J. Phys. D: Appl. Phys.

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Expressions are derived and discussed for the local mean intensity of the two-dimensional images of ocean waves produced by a synthetic aperture radar (SAR). Accounts are taken of the spatial and temporal changes of both back-scattered radar cross-section and ocean wave height. It is shown that the images of ocean waves are distorted as a result of radar layover. This imaging process is similar to velocity bunching by the effect is largest for range waves and it vanishes for azimuth waves. The mechanism of defocusing is also investigated. If reference signals are designed for stationary objects, the images of dynamic waves are always defocused, irrespective of their propagation direction and of the types of imaging processes, including radar layover, velocity bunching and back-scattered cross-section. Defocusing originates from the systematic degradation and upgradation of point spread (impulse response) functions associated with the periodic structure of the waves. The images can be enhanced by applying a defocused azimuth reference signal and the amount of defocusing for optimum images depends only on the wave phase velocity and propagation direction.

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Section: H ( X Y ; L ) = Hm(x Y ; L) + Hr(x Y ;supporting

confidence: 89%

Section: Of Ocean Wavessupporting

confidence: 71%

Section: Introductionmentioning

confidence: 88%

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Two-dimensional imaging mechanisms of ocean waves by synthetic aperture radars

Ouchi¹

1984

J. Phys. D: Appl. Phys.

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“…First, an analysis of the SAR is presented. The analysis extends the work of Ivanov (1982) and Ouchi (1984) and avoids the use o f linear superpositon with a point spread function. Secondly, it is shown that a wide range of the properties of SAR oceanic imaging follow, in a rigorous and thoroughly self-consistent way, from such an approach.…”

Section: Introductionmentioning

confidence: 87%

“…The analysis is an extension of that of Ivanov (1982) and Ouchi (1984). However, this paper is not intended as a general review of ocean imaging theories.…”

Section: Introductionmentioning

confidence: 99%

Synthetic aperture radar imaging of ocean surface waves: multi-look and single-look systems

Burridge

1992

International Journal of Remote Sensing

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A single two-dimensional expression is givcn for the (speckleaveraged) image associated with a model of ocean swell which may be applied to single-look and multi-look synthetic aperture radar (SAR) systems (albeit with different arguments). That expression accommodates real and artificial crosssection modulation mechanisms, shows rescaling elfects (i.e. rotation of the image of a wavefield), suggests the use of processor refocusing to maximize image contrast, accounts for scene coherence, and indicates a variation of image contrast with range (assuming homogeneous swell). Most of the above have been observed and discussed previously in the literature. However, in this paper it is shown that all the effects are derived (simultaneously) by a relatively simple, rigorous and self-consistent analysis: it is not always necessary to treat the SAR imaging of ocean waves in a piece-wise manner. The analysis dilfers from that most frequently found in the literature. A space-time variant point spread function is not presumed: and some of the conclusions. in particular with regard to the optimum image processing strategy, differ with those following the use of the more conventional forms of analysis. Throughout, care is taken to minimize, but also to make explicit, the underlying assumptions in the treatment.

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Inverse Methods for Ocean Wave Imaging by SAR

Rotheram¹,

Macklin²

1985

Inverse Methods in Electromagnetic Imaging

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On the synthetic aperture radar imaging of ocean surface waves

Cited by 21 publications

References 9 publications

Two-dimensional imaging mechanisms of ocean waves by synthetic aperture radars

Two-dimensional imaging mechanisms of ocean waves by synthetic aperture radars

Synthetic aperture radar imaging of ocean surface waves: multi-look and single-look systems

Inverse Methods for Ocean Wave Imaging by SAR

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