Waveform Design for Synthetic-Aperture Radar Imaging through Dispersive Media

Varslot, Trond; Morales, J. Héctor; Cheney, Margaret

doi:10.1137/100802438

Cited by 6 publications

(27 citation statements)

References 26 publications

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“…The sensing precursor is analogous to Oughstun's Brillouin pulse [19]. We compare the propagation and imaging performance of this sensing precursor to that of the optimal waveform derived by Varslot et al [27]. Our results show that, in general, the optimal waveform of Varslot et al [27] is not a precursor waveform.…”

Section: Introductionmentioning

confidence: 80%

“…We compare the propagation and imaging performance of this sensing precursor to that of the optimal waveform derived by Varslot et al [27]. Our results show that, in general, the optimal waveform of Varslot et al [27] is not a precursor waveform. For high levels of signal-to-noise ratio (SNR), the optimal waveform is comprised of frequencies higher than those that comprise the sensing precursor.…”

Section: Introductionmentioning

confidence: 83%

“…The optimal waveform is numerically derived for each noise level by solving a fixed-point equation for the absolute value of the optimal pulse spectrum and then applying a minimum-phase algorithm to obtain the optimal waveform. The authors conclude that the optimal minimum-phase waveforms have a 'transmit spectrum that is concentrated around the frequencies which are conducive to the generation of precursors' [27], but no conclusive statement could be made.…”

Section: Introductionmentioning

confidence: 97%

“…The question of whether or not the Brillouin precursor is the ideal waveform for synthetic aperture radar (SAR) imaging through dispersive material was partially addressed by Varslot, Morales, and Cheney in a pair of papers appearing in 2010 and 2011 [26,27]. These authors used a filtered back-projection algorithm to derive an optimal filter and its associated optimal waveform.…”

Section: Introductionmentioning

confidence: 99%

“…In section 2 of this paper, we provide a brief history and derivation of the Brillouin precursor and Brillouin pulse in dispersive material. In section 3, we formulate the imaging problem and give a description of the optimal minimum-phase results of [26,27]. Section 4 derives the sensing precursor for an isotropic point scatterer.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Precursors for synthetic aperture radar

Cartwright

Muller

2023

Inverse Problems

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In this paper we study waveform design for synthetic-aperture radar (SAR) imaging through dispersive media. Under the assumptions of scalar wave propagation through a causal dielectric medium and single-scattering from an isotropic point scatterer, we use asymptotic analysis to derive the asymptotic approximation to the scattered electric field. From this asymptotic approximation, we define a sensing precursor that we propose for the transmit waveform for SAR imaging through dispersive material. We compare our sensing precursor with previously defined optimal waveforms (Varslot, Morales, and Cheney, Waveform design for synthetic-aperture radar imaging through dispersive media, SIAM J. Appl. Math., 71 (2011), pp. 1780 - 1800) in terms of both propagation and scattering capabilities, as well as imaging performance. With the filtered back-projection imaging algorithm that we use, we find that for high levels of signal-to-noise ratio (SNR), the optimal waveforms contain higher frequencies and thus produce better images. For low levels of SNR, the transmitted optimal waveforms and the sensing precursors are similar, thus giving comparable images.

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Section: Introductionmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Precursors for synthetic aperture radar

Cartwright

Muller

2023

Inverse Problems

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Discussion and outstanding questions

Gilman

Smith

Tsynkov

2017

Transionospheric Synthetic Aperture Imaging

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Upscaling mass adsorption and momentum transport in the crown of trees

Valdés-Parada,

Sánchez-Vargas

2024

Physics of Fluids

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Airborne chemical species transport and adsorption in the crown of trees are relevant processes with many crucial environmental consequences. This multiphase and multiscale process requires incorporation of momentum transport both in the air and in the solid phases composing the biomass (leaves and branches) and coupling with species mass transport. In this work, an upscaled model for momentum transport and adsorption of chemical species in tree crowns is derived using the method of volume averaging. The model comprises four effective-medium equations, namely: the macroscopic balance equation for momentum transport in the air, which has a Darcy-like structure; the macroscopic equations for total mass and momentum transport, considering the air and deformable leaves and branches; and an unsteady upscaled equation for species mass (diffusive and convective) transport and adsorption at the surface of leaves and branches. These equations are written in terms of effective-medium coefficients that capture the essential microscale information by solving ancillary closure problems in periodic unit cells in the Laplace domain. This allowed evaluating the dynamic functionality of the unsteady adsorption and dispersion coefficients in terms of the Reynolds number, the solid velocity and the adsorption rate. The macroscopic model predictions of the average chemical species concentration were found to be in excellent agreement with direct numerical simulations (i.e., with a relative percent difference smaller than 1%), thus providing a first validation of the upscaled model. Extensions to other systems are briefly discussed.

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Waveform Design for Synthetic-Aperture Radar Imaging through Dispersive Media

Cited by 6 publications

References 26 publications

Precursors for synthetic aperture radar

Precursors for synthetic aperture radar

Discussion and outstanding questions

Upscaling mass adsorption and momentum transport in the crown of trees

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