@article{gilman_tsynkov_2024, title={Modeling the Earth's Ionosphere by a Phase Screen for the Analysis of Transionospheric SAR Imaging}, volume={62}, ISSN={["1558-0644"]}, DOI={10.1109/TGRS.2023.3335146}, abstractNote={In the problems of transionospheric synthetic aperture radar (SAR) imaging, autofocus, and ionospheric tomography, the Earth’s ionosphere is often represented by a phase screen. A key advantage of the phase screen is that it reduces the overall dimension of the model. Yet, this convenient simplification comes at a price of introducing inaccuracies into the modeled quantities, such as the phase of the propagating radar signals. In this work, we develop the appropriate metrics to quantify these inaccuracies and evaluate their role for two particular scenarios: SAR imaging through large-scale ionospheric disturbances due to the atmospheric gravity waves (AGWs) and SAR imaging through ionospheric turbulence.}, journal={IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2024} }
 @article{gilman_tsynkov_2023, title={Transionospheric Autofocus for Synthetic Aperture Radar}, volume={16}, ISSN={["1936-4954"]}, DOI={10.1137/22M153570X}, number={4}, journal={SIAM JOURNAL ON IMAGING SCIENCES}, author={Gilman, Mikhail and Tsynkov, Semyon V.}, year={2023}, pages={2144–2174} }
 @article{gilman_tsynkov_2023, title={Transionospheric Autofocus for Synthetic Aperture Radar}, ISSN={["2835-1355"]}, DOI={10.1109/ICEAA57318.2023.10297676}, abstractNote={Synthetic aperture radar (SAR) illuminates the target with microwaves and uses digital signal processing to build the image. For a spaceborne SAR, the antenna is mounted on a satellite, whereas the target area is on the ground. The antenna emits pulses of electromagnetic radiation and receives the returns, i.e., signals reflected off the target. The signal processing algorithm takes into account multiple pulses emitted and received by the antenna at a series of its successive positions, called the synthetic aperture. The resulting image approximates the backscattering reflectivity of the target. Mathematically, SAR imaging is equivalent to solving an inverse problem - that of reconstructing the unknown target reflectivity given radar returns as the input data.}, journal={2023 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS, ICEAA}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2023}, pages={24–24} }
 @article{gilman_tsynkov_2023, title={Vertical autofocus for the phase screen in a turbulent ionosphere}, volume={39}, ISSN={["1361-6420"]}, DOI={10.1088/1361-6420/acb8d6}, abstractNote={The performance of spaceborne synthetic aperture radars (SARs) is affected by the Earth’s ionosphere. In particular, the ionospheric turbulence causes phase perturbations of the SAR signals, which may lead to image distortions. A convenient way to model those phase perturbations is by means of a phase screen. The latter is an infinitesimally thin layer positioned at a certain elevation above the Earth’s surface. The radar signal acquires an instant perturbation once its trajectory intersects the screen. The trajectory is a ray between the antenna and the target, and the magnitude of the perturbation is equal to the screen density at the intersection point. The density is a bivariate function of the coordinates along the screen. The coordinates of a specific intersection point are determined by the ray itself, as well as the screen elevation. Thus, the magnitude of the phase perturbation explicitly depends on the screen elevation. Accordingly, to compensate for the resulting image distortions one should be able to determine the elevation of the screen. In the paper, we develop an algorithm of vertical autofocus that derives this elevation from the received SAR data, given a pair of point scatterers in the target area. The proposed algorithm exploits a modification of the coherent interferometric imaging that was previously employed to reduce the effect of phase errors due to the trajectory uncertainty. In our analysis, we highlight the differences between this case and transionospheric propagation.}, number={4}, journal={INVERSE PROBLEMS}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2023}, month={Apr} }
 @article{gilman_tsynkov_2022, title={Polarimetric radar interferometry in the presence of differential Faraday rotation}, volume={38}, ISSN={["1361-6420"]}, DOI={10.1088/1361-6420/ac5525}, abstractNote={Faraday rotation (FR) affects the low-frequency transionospheric radar by creating cross-talk between polarizations. The baseline part of FR can be compensated for by applying an appropriate linear transformation—rotation with a known FR angle. Yet the differential Faraday rotation (dFR), which is a frequency-dependent part of FR, persists and introduces distortions into the observations. We build a simplified model with two polarimetric scattering channels that allows us to evaluate the effect of dFR on the accuracy of PolInSAR reconstruction. We also assess the severity of distortions due to dFR for the future BIOMASS mission and several other spaceborne radar systems.}, number={4}, journal={INVERSE PROBLEMS}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2022}, month={Apr} }
 @article{gilman_tsynkov_2021, title={A MATHEMATICAL PERSPECTIVE ON RADAR INTERFEROMETRY}, volume={7}, ISSN={["1930-8345"]}, DOI={10.3934/ipi.2021043}, abstractNote={Radar interferometry is an advanced remote sensing technology that utilizes complex phases of two or more radar images of the same target taken at slightly different imaging conditions and/or different times. Its goal is to derive additional information about the target, such as elevation. While this kind of task requires centimeter-level accuracy, the interaction of radar signals with the target, as well as the lack of precision in antenna position and other disturbances, generate ambiguities in the image phase that are orders of magnitude larger than the effect of interest.Yet the common exposition of radar interferometry in the literature often skips such topics. This may lead to unrealistic requirements for the accuracy of determining the parameters of imaging geometry, unachievable precision of image co-registration, etc. To address these deficiencies, in the current work we analyze the problem of interferometric height reconstruction and provide a careful and detailed account of all the assumptions and requirements to the imaging geometry and data processing needed for a successful extraction of height information from the radar data. We employ two most popular scattering models for radar targets: an isolated point scatterer and delta-correlated extended scatterer, and highlight the similarities and differences between them.}, journal={INVERSE PROBLEMS AND IMAGING}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2021}, month={Jul} }
 @article{lagergren_flores_gilman_tsynkov_2021, title={Deep Learning Approach to the Detection of Scattering Delay in Radar Images}, volume={15}, ISSN={["1559-8616"]}, DOI={10.1007/s42519-020-00149-w}, number={1}, journal={JOURNAL OF STATISTICAL THEORY AND PRACTICE}, author={Lagergren, John and Flores, Kevin and Gilman, Mikhail and Tsynkov, Semyon}, year={2021}, month={Mar} }
 @article{gilman_tsynkov_2021, title={Divergence Measures and Detection Performance for Dispersive Targets in SAR}, volume={56}, ISSN={["1944-799X"]}, DOI={10.1029/2019RS007011}, abstractNote={When electromagnetic waves impinge on objects with complex geometries and/or internal structure, we can observe scattering that is distributed in time rather than instantaneous. To detect and characterize such targets, we build the coordinate‐delay synthetic aperture radar (cdSAR) images by adding a delay term to the standard SAR matched filter. In order to apply this approach to the case of extended targets where the image intensity and phase are subject to strong and rapid variations (the phenomenon called speckle), we sample the cdSAR image at several coordinate‐delay “points” in the vicinity of the scatterer location. The discrimination between the instantaneous and delayed targets is realized through autocorrelation analysis of this sample. Because of the statistical properties of speckle, misclassification errors are inevitable. Hence, prediction of the error rate as a function of system and target parameters becomes an important problem. While Monte Carlo simulations can generate the ensembles of data for direct calculation of the error rate, this approach is computationally demanding because of its slow convergence. In order to simplify the prediction of the error rate, we employ statistical divergence measures, namely, the Hellinger distance and Kullback‐Leibler divergence. These divergence measures are calculated directly from the theoretical models of reflectivity of extended targets that we want to distinguish. We empirically establish a linear relation between the misclassification rate and the Hellinger distance for a certain class of simple target models. This relation allows us to make predictions of the error rate without performing the Monte Carlo simulations.}, number={1}, journal={RADIO SCIENCE}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2021}, month={Jan} }
 @article{gilman_tsynkov_2020, title={STATISTICAL CHARACTERIZATION OF SCATTERING DELAY IN SYNTHETIC APERTURE RADAR IMAGING}, volume={14}, ISSN={["1930-8345"]}, DOI={10.3934/ipi.2020024}, abstractNote={Distinguishing between the instantaneous and delayed scatterers in synthetic aperture radar (SAR) images is important for target identification and characterization. To perform this task, one can use the autocorrelation analysis of coordinate-delay images. However, due to the range-delay ambiguity the difference in the correlation properties between the instantaneous and delayed targets may be small. Moreover, the reliability of discrimination is affected by speckle, which is ubiquitous in SAR images, and requires statistical treatment. 
Previously, we have developed a maximum likelihood based approach for discriminating between the instantaneous and delayed targets in SAR images. To test it, we employed simple statistical models. They allowed us to simulate ensembles of images that depend on various parameters, including aperture width and target contrast. 
In the current paper, we enhance our previously developed methodology by establishing confidence levels for the discrimination between the instantaneous and delayed scatterers. Our procedure takes into account the difference in thresholds for different target contrasts without making any assumptions about the statistics of those contrasts.}, number={3}, journal={INVERSE PROBLEMS AND IMAGING}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2020}, month={Jun}, pages={511–533} }
 @article{gilman_tsynkov_2018, title={Differential Faraday Rotation and Polarimetric SAR}, volume={78}, ISSN={0036-1399 1095-712X}, url={http://dx.doi.org/10.1137/17M114042X}, DOI={10.1137/17m114042x}, abstractNote={The propagation of linearly polarized electromagnetic waves through the Earth's ionosphere is accompanied by Faraday rotation (FR), which is due to gyrotropy of the ionospheric plasma in the magnet...}, number={3}, journal={SIAM Journal on Applied Mathematics}, publisher={Society for Industrial & Applied Mathematics (SIAM)}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2018}, month={Jan}, pages={1422–1449} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={Conventional SAR imaging}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_2}, abstractNote={In this chapter, we explain the fundamental principles of SAR data collection and image formation, i.e., inversion of the received data. Synthetic aperture radar uses microwaves for imaging the surface of the Earth from airplanes or satellites. Unlike photography which generates the picture by essentially recoding the intensity of the light reflected off the different parts of the target, SAR imaging exploits the phase information of the interrogating signals and as such can be categorized as a coherent imaging technology.}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={19–57} }
 @article{gilman_smith_tsynkov_2017, title={Inverse scattering off anisotropic targets}, journal={Transionospheric synthetic aperture imaging}, author={Gilman, M. and Smith, E. and Tsynkov, S.}, year={2017}, pages={373–415} }
 @inproceedings{gilman_tsynkov_2017, title={Mathematical analysis of SAR imaging through a turbulent ionosphere}, volume={1895}, ISSN={["0094-243X"]}, url={http://dx.doi.org/10.1063/1.5007357}, DOI={10.1063/1.5007357}, abstractNote={Synthetic aperture radar (SAR) imaging though the Earth ionosphere is subject to distortions due to ionospheric turbulence. We consider the limiting cases of small-scale and large-scale turbulence and characterize the distortions in terms of image blurring and azimuthal shift. It is shown that in the large-scale case, a high level of eikonal fluctuations can coexist with the low degree of image distortions, and that blurring becomes significant at much higher levels of fluctuations than the shift. In the small-scale case, a low level of eikonal fluctuations is a precondition for imaging, while the magnitude of distortions depends on the ratio between the eikonal correlation radius and the length of the synthetic aperture.}, publisher={Author(s)}, author={Gilman, M. and Tsynkov, S.}, editor={Todorov, Michail D.Editor}, year={2017} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={Modeling radar targets beyond the first Born approximation}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_7}, abstractNote={In this chapter, we return to the foundations of the SAR ambiguity theory SAR ambiguity theory that we presented in Chapter 2 , and address the inconsistencies of the conventional approach outlined in Section 2.7 A standard representation of the image in the SAR ambiguity theory is SAR image by the convolution integral convolution ( 2.1 ) [see also ( 2.31 )]:}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={311–371} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={SAR imaging through the Earth's ionosphere}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_3}, abstractNote={When the signal of a spaceborne radar travels between the satellite and the ground, it becomes subject to the temporal dispersion of radio waves in the Earth’s ionosphere [18]. dispersion temporal The dispersion distorts the signal, and if the matched filter does not properly account for that, a mismatch occurs and the quality of the image deteriorates. The extent of deterioration becomes smaller as the ratio of the Langmuir frequency of the ionospheric plasma to the carrier frequency of the radar decreases. This is a part of the reason why many modern spaceborne SAR instruments operate in higher frequency bands. For example, TerraSAR-X operates in the X-band, on the frequency of 9.6GHz. X-band}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={59–161} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={The effect of ionospheric anisotropy}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_5}, abstractNote={In Chapter 3, we have shown that the Earth’s ionosphere exerts an adverse effect on SAR imaging. It is due to the mismatch between the actual radar signal affected by the dispersion of radio waves in the ionosphere and the matched filter used for signal processing. Accordingly, to improve the image one should correct the filter. This requires knowledge of the total electron content in the ionosphere, as well as of another parameter that characterizes the azimuthal variation of the electron number density (see Section 3.9). These quantities can be reconstructed by probing the ionosphere on two distinct carrier frequencies and exploiting the resulting redundancy in the data (see Section 3.10).}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={217–264} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={The effect of ionospheric turbulence}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_4}, abstractNote={In Chapter 3, we have shown that temporal dispersion of the propagation medium (Earth’s ionosphere) causes distortions of SAR images (see Section 3.8). Moreover, we have identified the key integral characteristics of the ionospheric plasma that allow one to quantify those distortions. They are the zeroth moment of the electron number density N e, i.e., the TEC N H given by (3.66), as well the first moment $$\mathcal{Q}$$ of the azimuthal derivative of N e defined by ( 3.182 ). We have also demonstrated that one can obtain the unknown quantities N H and $$\mathcal{Q}$$ with the help of dual carrier probing (see Section 3.10 ) and subsequently incorporate them into the SAR matched filter matched filter in order to effectively eliminate the distortions (see Section 3.11 ). This correction of the filter is possible because one and the same pair of values $$(N_{H},\mathcal{Q})$$ “serves” all antenna signals used for the construction of the image, i.e., all the terms in the azimuthal sum. Once the values of N H and $$\mathcal{Q}$$ have been derived, the corrected filter will match the received signals for all antenna positions along the synthetic array.}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={163–215} }
 @article{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, title={The start-stop approximation}, ISBN={["978-3-319-52125-1"]}, DOI={10.1007/978-3-319-52127-5_6}, abstractNote={For the analysis of the SAR data inversion algorithm in Chapters 2 through 5, we have employed the start-stop approximation, which is considered standard in the literature, see, e.g., [25, 40, 76, 79] and also [86]. It assumes that the radar antenna is at standstill while it sends the interrogating pulse toward the target and receives the scattered response, after which the antenna moves down the flight track to the position where the next pulse is emitted and received.}, journal={TRANSIONOSPHERIC SYNTHETIC APERTURE IMAGING}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={265–309} }
 @book{gilman_smith_tsynkov_gilman_smith_tsynkov_2017, place={Cham, Switzerland}, title={Transionospheric Synthetic Aperture Imaging}, ISBN={9783319521251 9783319521275}, ISSN={2296-5009 2296-5017}, url={http://dx.doi.org/10.1007/978-3-319-52127-5}, DOI={10.1007/978-3-319-52127-5}, abstractNote={This landmark monograph presents the most recent mathematical developments in the analysis of ionospheric distortions of SAR images and offers innovative new strategies for their mitigation. As a prer}, journal={Applied and Numerical Harmonic Analysis}, publisher={Springer International Publishing}, author={Gilman, M. and Smith, E. and Tsynkov, S. and Gilman, M and Smith, E and Tsynkov, S}, year={2017}, pages={1–1} }
 @book{gilman_smith_tsynkov_2017, title={Transionospheric Synthetic Aperture Imaging}, volume={xxiii}, journal={Birkhäuser}, author={Gilman, M. and Smith, E. and Tsynkov, S.}, year={2017} }
 @article{gilman_smith_tsynkov_2017, title={Transionospheric Synthetic Aperture Imaging Discussion and outstanding questions}, journal={Transionospheric synthetic aperture imaging}, author={Gilman, M. and Smith, E. and Tsynkov, S.}, year={2017}, pages={417–431} }
 @article{gilman_smith_tsynkov_2017, title={Transionospheric synthetic aperture imaging Introduction}, journal={Transionospheric synthetic aperture imaging}, author={Gilman, M. and Smith, E. and Tsynkov, S.}, year={2017}, pages={1–17} }
 @article{gilman_tsynkov_2015, title={A Mathematical Model for SAR Imaging beyond the First Born Approximation}, volume={8}, ISSN={1936-4954}, url={http://dx.doi.org/10.1137/140973025}, DOI={10.1137/140973025}, abstractNote={The assumption of weak scattering is standard for the mathematical analysis of synthetic aperture radar (SAR), as it helps linearize the inverse problem via the first Born approximation and thus makes it amenable to solution. Yet it is not consistent with another common assumption, that the interrogating waves do not penetrate into the target material and get scattered off its surface only, which essentially means that the scattering is strong. In the paper, we revisit the foundations of the SAR ambiguity theory in order to address this and other existing inconsistencies, such as the absence of the Bragg scale in scattering. We introduce a new model for radar targets that allows us to compute the scattered field from first principles. This renders the assumption of weak scattering unnecessary yet keeps the overall inverse scattering problem linear. Finally, we show how one can incorporate the Leontovich boundary condition into SAR ambiguity theory.}, number={1}, journal={SIAM Journal on Imaging Sciences}, publisher={Society for Industrial & Applied Mathematics (SIAM)}, author={Gilman, Mikhail and Tsynkov, Semyon}, year={2015}, month={Jan}, pages={186–225} }
 @article{gilman_smith_tsynkov_2014, title={Single-polarization SAR imaging in the presence of Faraday rotation}, volume={30}, ISSN={0266-5611 1361-6420}, url={http://dx.doi.org/10.1088/0266-5611/30/7/075002}, DOI={10.1088/0266-5611/30/7/075002}, abstractNote={We discuss the single-polarization SAR imaging with the Faraday rotation (FR) taken into account. The FR leads to a reduction in the intensity of the received radar signal that varies over the signal length. That, in turn, results in a degradation of the image. In particular, the image of a point target may have its intensity peak split in the range direction. To distinguish between the cases of low reflectivity and those where the low antenna signal is due to the FR, we employ the image autocorrelation analysis. This analysis also helps determine the parameters of the FR, which, in turn, allow us to introduce an approach for correcting the single-polarization SAR images distorted by FR.}, number={7}, journal={Inverse Problems}, publisher={IOP Publishing}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon}, year={2014}, month={Jun}, pages={075002} }
 @article{gilman_smith_tsynkov_2013, title={Reduction of ionospheric distortions for spaceborne synthetic aperture radar with the help of image registration}, volume={29}, ISSN={0266-5611 1361-6420}, url={http://dx.doi.org/10.1088/0266-5611/29/5/054005}, DOI={10.1088/0266-5611/29/5/054005}, abstractNote={We propose a robust technique for reducing the ionospheric distortions in spaceborne synthetic aperture radar (SAR) images. It is based on probing the terrain on two distinct carrier frequencies. Compared to our previous work on the subject (Smith and Tsynkov 2011 SIAM J. Imaging Sciences 4 501–42), the increase in robustness is achieved by applying an area-based image registration algorithm to the two images obtained on two frequencies. This enables an accurate evaluation of the shift between the two images, which, in turn, translates into an accurate estimate of the total electron content and its along-track gradient in the ionosphere. These estimates allow one to correct the matched filter and thus improve the quality of the image. Moreover, for the analysis of SAR resolution in the current paper we take into account the Ohm conductivity in the ionosphere (in addition to its temporal dispersion), and also consider the true Kolmogorov spectrum of the ionospheric turbulence, as opposed to its approximate representation that we have used previously.}, number={5}, journal={Inverse Problems}, publisher={IOP Publishing}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon}, year={2013}, month={Apr}, pages={054005} }
 @article{gilman_smith_tsynkov_2012, title={A linearized inverse scattering problem for the polarized waves and anisotropic targets}, volume={28}, ISSN={0266-5611 1361-6420}, url={http://dx.doi.org/10.1088/0266-5611/28/8/085009}, DOI={10.1088/0266-5611/28/8/085009}, abstractNote={We analyze the scattering of a plane transverse linearly polarized electromagnetic wave off a plane interface between the vacuum and a given material. For a variety of predominantly dielectric materials, from isotropic to anisotropic and weakly conductive, we show that when the scattering is weak, the first Born approximation predicts the correct scattered field in the vacuum region. We also formulate and solve the corresponding linearized inverse scattering problem. Specifically, we provide a necessary and sufficient condition under which interpreting the target material as a weakly conductive uniaxial crystal allows one to reconstruct all the degrees of freedom contained in the complex 2 × 2 Sinclair scattering matrix. This development can help construct a full-fledged radar ambiguity theory for polarimetric imaging by means of a synthetic aperture radar (SAR), which is in contrast to the approach that currently dominates the SAR literature and exploits a fully phenomenological scattering matrix. Moreover, the linearized scattering off a material half-space naturally gives rise to the ground reflectivity function in the form of a single layer (i.e. a δ-layer) at the interface. A ground reflectivity function of this type is often introduced in the SAR literature without a rigorous justification. Besides the conventional SAR analysis, we expect that the proposed approach may appear useful for the material identification SAR (miSAR) purposes.}, number={8}, journal={Inverse Problems}, publisher={IOP Publishing}, author={Gilman, Mikhail and Smith, Erick and Tsynkov, Semyon}, year={2012}, month={Jul}, pages={085009} }
 @inbook{soloviev_matt_gilman_huhnerfuss_haus_jeong_savelyev_donelan_2011, title={Modification of turbulence at the air-sea interface due to the presence of surfactants and implications for gas exchange. Part I: laboratory experiment}, booktitle={Gas Transfer at Water Surfaces}, publisher={Kyoto University Press}, author={Soloviev, A. and Matt, S. and Gilman, M. and Huhnerfuss, H. and Haus, B. and Jeong, D. and Savelyev, I. and Donelan, M.}, year={2011}, pages={245–258} }
 @article{gilman_soloviev_graber_2011, title={Study of the Far Wake of a Large Ship}, volume={28}, ISSN={0739-0572 1520-0426}, url={http://dx.doi.org/10.1175/2010jtecho791.1}, DOI={10.1175/2010jtecho791.1}, abstractNote={Abstract}, number={5}, journal={Journal of Atmospheric and Oceanic Technology}, publisher={American Meteorological Society}, author={Gilman, M. and Soloviev, A. and Graber, H.}, year={2011}, month={May}, pages={720–733} }
 @article{soloviev_gilman_young_brusch_lehner_2010, title={Sonar Measurements in Ship Wakes Simultaneous With TerraSAR-X Overpasses}, volume={48}, ISSN={0196-2892 1558-0644}, url={http://dx.doi.org/10.1109/tgrs.2009.2032053}, DOI={10.1109/tgrs.2009.2032053}, abstractNote={A pilot experiment was conducted in the period from April to June 2008 in the Straits of Florida near Port Everglades, Florida, in order to study the dynamics of far wakes of ships. In this experiment, a small boat with downward-looking sonar made ¿snakelike¿ sections through wakes of ships of opportunity during the TerraSAR-X overpasses. The ship and its parameters (length, speed, course, etc.) were identified utilizing an automated identification system. The sonar responded to the clouds of microbubbles generated in the ship wake by the propulsion system and ship-hull turbulence. The ship wakes were traced in the sonar signal typically from 10 to 30 min after the ship's passage. A preliminary analysis of the measurements suggests that the visibility of the centerline ship wake in synthetic aperture radar (SAR) images is correlated with the presence of microbubbles in the wake. This supports the hypothesis that natural surfactants scavenged and brought to the surface by rising bubbles play an important role in the wake visibility in SAR. The influence of the wind-wave field on the ship wake, as well as the effect of screening of the wind-wave field by the ship's hull, adds another level of complexity to wake patterns observed in SAR images.}, number={2}, journal={IEEE Transactions on Geoscience and Remote Sensing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Soloviev, A. and Gilman, M. and Young, K. and Brusch, S. and Lehner, S.}, year={2010}, month={Feb}, pages={841–851} }
 @article{gilman_sadov_shamaev_shamaev_2000, title={Radar Sensing of Sea Surface: Some Problems of Numerical Simultaion of Scattering of Electromagnetic Waves, review}, volume={45}, number={2}, journal={Radiotechnics and Electronics}, author={Gilman, M.A. and Sadov, S. Yu and Shamaev, A.S. and Shamaev, S.I.}, year={2000}, pages={229–246} }
 @article{gilman_1997, title={Bispectrum and Analysis of the Statistics of Electromagnetic Waves Backscattered by Sea Surface}, volume={36}, number={6}, journal={Journal of Computer and System Sciences International}, author={Gilman, M.A.}, year={1997}, pages={972–980} }
 @article{gilman_kirgetov_mikheev_tkachenko_shamaev_1996, title={Methods and Algorithms for Processing and Identification of Radar Images of the Ocean Surface}, volume={34}, number={6}, journal={Journal of Computer and System Sciences International}, author={Gilman, M.A. and Kirgetov, A.V. and Mikheev, A.G. and Tkachenko, T.L. and Shamaev, A.S.}, year={1996}, pages={155–175} }
 @article{gilman_mikheev_tkachenko_1996, title={The Two-scale Model and Other Methods For the Approximate Solution of the Problem of Diffraction by Rough Surfaces}, volume={36}, number={10}, journal={Journal of Computational Mathematics and Mathematical Physics}, author={Gilman, M.A. and Mikheev, A.G. and Tkachenko, T.L.}, year={1996}, pages={1429–1442} }
 @article{bingham_shapiro_tsytovich_de angelis_gilman_shevchenko_1991, title={Theory of wave activity occurring in the AMPTE artificial comet}, volume={3}, ISSN={0899-8221}, url={http://dx.doi.org/10.1063/1.859984}, DOI={10.1063/1.859984}, abstractNote={One of the main experiments of the Active Magnetospheric Particle Tracer Explorers (AMPTE) [J. Geophys. Res. 91, 10013 (1986)] satellite mission was the release of neutral barium atoms in the solar wind. The barium atoms ionized by photoionization extremely rapidly forming a dense, expanding, plasma cloud that interrupted the solar wind flow creating diamagnetic cavities. On the upstream side of the cavity a region of compressed plasma and enhanced magnetic field was created as the result of being produced by the slowing down and deflection of the solar wind, and magnetic field line draping. Intense electrostatic and magnetic turbulence was observed by both the IRM [J. Geophys. Res. 91, 10 013 (1986)] and UKS [J. Geophys. Res. 91, 1320 (1986)] satellites at the boundary of the diamagnetic cavity, with the most intense waves being detected near the outer boundary of the compressed region. This paper examines how the newly created expanding plasma couples to the solar wind by means of plasma–beam and current-driven instabilities. In particular, it is shown how lower-hybrid and lower-hybrid drift waves are generated by cross-field proton–barium streaming instabilities and cross-field electron currents. The saturation mechanism for these waves is considered to be the modulational instability, this instability can also lead to filamentation and coupling to magnetosonic modes, which are also observed. As the result of modulational instability the k∥ component increases, which allows the heating and acceleration of electrons that is consistent with the observations.}, number={7}, journal={Physics of Fluids B: Plasma Physics}, publisher={AIP Publishing}, author={Bingham, R. and Shapiro, V. D. and Tsytovich, V. N. and de Angelis, U. and Gilman, M. and Shevchenko, V. I.}, year={1991}, month={Jul}, pages={1728–1738} }
 @article{gilman_khrabrov_1987, title={Nonlinear Dynamics of the Cyclotron Instability of a Fast Ion Beam}, volume={13}, number={12}, journal={Soviet Journal of Plasma Physics}, author={Gilman, M. and Khrabrov, A.}, year={1987}, pages={824–828} }