This study addresses a novel application of global navigation satellite system-reflectometry (GNSS-R) delay-Doppler maps (DDMs), namely sea target detection. In contrast with other competing remote sensing technologies, such as synthetic aperture radar and optical systems, typically exploited in the field detection, GNSS-R systems could be employed constellations, so to fulfill temporal requirements for near real-time ships ice sheets monitoring. this study, revisit time offered by is...

Maritime surveillance (MS) is crucial for search and rescue operations, fishery monitoring, pollution control, law enforcement, migration national security policies. Since the early days of seafaring, MS has been a critical task providing in human coexistence. Several generations sensors detailed maritime information have become available large offshore areas real time: radar 1950s automatic identification system (AIS) 1990s among them. However, ground-based radars AIS data do not always...

Speckle noise greatly limits both synthetic aperture radar (SAR) data human readability, especially for non-SAR-expert users, and performance of automatic processing information retrieval procedures by computer programs. Therefore, despeckling SAR images is an essential preprocessing step in analysis, processing, modeling, as well inversion procedures. Up to now, one the most accurate promising approaches - among those based on a single image relying nonlocal means concepts. However, at best...

Maritime surveillance (MS) is of paramount importance for search and rescue operations, fishery monitoring, pollution control, law enforcement, migration national security policies. Since ground-based radars automatic identification system (AIS) do not always provide a comprehensive seamless coverage the entire maritime domain, use space-based sensors crucial to complement them. We reviewed technologies MS in first part this work, titled "Space-based Global Surveillance. Part I: Satellite...

Interpreting synthetic aperture radar (SAR) images may be a very challenging task, even for expert users. One of the main reasons is multiplicative speckle noise typical coherent acquisition systems. Therefore, despeckling can expected to play key role in full exploitation SAR imagery potential. However, state-of-the-art algorithms neglect physical phenomena hidden behind imagery. Image depends on electromagnetic scattering, which also at basis noise. Taking into account scattering issues...

In this article, we present a fully analytical model for the evaluation of electromagnetic (EM) field scattered from composite target in generic bistatic configuration. The scenario comprises rectangular parallelepiped with smooth dielectric faces lying over rough background surface, modeled as stochastic process. single- and multiple-bounce scattering contributions arising target, background, their interactions have been derived under Kirchhoff approximation (KA)-geometrical optics (GO)...

Bistatic radars have been a topic of increasing interest in recent years, thanks to the introduction new bistatic (and multistatic) configurations, including those based on opportunistic exploitation global navigation satellite systems (GNSSs). The research electromagnetic scattering models plays an important role analysis these systems, their simulation, and prediction performance. two-scale model (TSM) is widely used approach for computation from rough surfaces, since it able account...

In this article, we carry out a simulation analysis of ship detection via Global Navigation Satellite System-Reflectometry (GNSS-R) delay-Doppler map (DDM). The GNSS-R DDM simulator used here is modified version an algorithm conceived for the generation DDMs sea surface. new based on analytical model radar cross section ships and able to properly account presence targets within scene. proposed is, then, exploited assessing viability in applications at low incidence angles, where adopted...

In this article, we propose a novel benchmarking framework for quantitative assessment of the performance despeckling algorithms multitemporal synthetic aperture radar (SAR) imagery. A number canonical scenes and data sets are analyzed so as to investigate both speckle reduction feature preservation capabilities filters. Despeckling is evaluated by proper quality measures that defined according scene. Due lack real-world speckle-free SAR images, proposed tool relies on an accurate...

The chance of exploiting the Global Navigation Satellite Systems-Reflectometry (GNSS-R) remote sensing technology in field maritime surveillance and ship traffic monitoring has been explored very recent past. conventional bistatic GNSS-R is based on acquisition GNSS navigation messages a forward-scattering geometry, where investigated region surrounds specular reflection point. peculiarities detection problem, man-made dihedral structures come into play, make configuration unsuitable for...

Natural surfaces exhibit scale-invariance properties and power-law spectra over a wide range of scales. For this reason, they are well described in the frame fractal geometry and, particular, using fractional Brownian motion (fBm) two-dimensional statistical processes. In paper, we present derivation correlation Global Navigation Satellite System reflectometry signals scattered by fBm surface. We here show that depends on parameter related to root-mean-square surface slope as measured at...

This paper investigates a novel application of Global Navigation Satellite System-Reflectometry (GNSS-R) in the fields maritime surveillance and safety, climate change analysis, namely sea target detection near real-time. Potentialities recent GNSS-R technology targets over (large ships, ice sheets) real-time are explored by: 1) computing revisit time achieved with constellations satellites; 2) deriving, implementing testing algorithm. The global average is evaluated by mission simulation...

Abstract This paper furnishes a convenient theoretical framework for the analytical evaluation of bistatic scattering coefficients, under Kirchhoff approximation (KA) in electromagnetics. Starting from KA, specific results geometrical optics and physical approximations are furnished, along with backscattering geometry. The main aim is to provide closed‐form expressions matrix that suited scenarios where multiple‐bounce comes into play and/or surfaces arbitrary unit normal present....

In this paper, a comparative study of spaceborne Global Navigation Satellite System (GNSS)-Reflectometry for ship detection applications is provided. The analysis conducted by evaluating the impact 1) acquisition geometry and 2) received signal polarization on detectability in GNSS-R data. particular, backscattering demonstrated to be more suitable applications, thus allowing 20 m-length ships. Even very large ships are hardly detectable conventional forward-scattering geometry. Moreover,...

In this paper, we first discuss some general problems and issues concerning Shape from Shading (SfS) Synthetic Aperture Radar (SAR) images present the state of art. Starting discussion, propose a new perspective introduce novel approach to SAR SfS based on fractals. particular, fractal geometry is used model shape natural surfaces, which are here concern. The scattering mechanisms described through solutions suitable for surface models; in Small Perturbation Method (SPM) used. Considering...

Marine and terrestrial natural surfaces exhibit statistical scale invariance properties that are well modelled by fractional Brownian motion (fBm), two-dimensional random processes. Accordingly, for microwave remote sensing applications it is useful to evaluate the normalized radar cross section (NRCS) of fBm surfaces. This task has been accomplished in past using either Kirchhoff approximation (KA) or small perturbation method (SPM). However, KA SPM have rather limited ranges application...

In the framework of passive multistatic radars, formation-flying synthetic aperture radar (FF-SAR) represents an intriguing remote sensing solution due to enhanced imaging capabilities with respect conventional SAR. this article, we focus on FF-SAR systems operating in a far-from-transmitter geometry, developing signal model suited specific configuration. Additionally, present efficient processing scheme that, by properly combining received raw echoes coherent fashion, enables two peculiar...

Speckle reduction in Synthetic Aperture Radar (SAR) images is an essential pre-processing step for a correct analysis and interpretation of SAR data. This justifies the huge effort image processing community to develop more accurate despeckling techniques order reduce speckle effects then improve readability imagery also non expert users. Up now, nonlocal means approaches provide most promising effective performances. In this paper we new non-local technique based on electromagnetic...

We present an analytical formulation of the correlation coefficient electromagnetic fields scattered at near-specular direction by a rough or gently undulating surface and measured two spatially separated positions occupied moving receiver slightly different times. This allows us obtaining explicit expression time received signal in terms radar parameters. work provides contribution to discussion, currently ongoing Global Navigation Satellite System Reflectometry (GNSS-R) scientific...

In this paper, we propose a range slope estimation procedure from single synthetic aperture radar (SAR) images with both methodological and applicative innovations. The retrieval algorithm is based on an analytical linearized direct model, which relates the SAR intensity data to local slopes encompasses surface model electromagnetic scattering model. Scene topography described via fractal geometry, whereas Small Perturbation Method adopted represent behavior of surface. map then used...

The paper focuses on the concept of a formation-flying synthetic aperture radar (FF-SAR) bistatic system composed set compact, low-weight satellite receivers in close formation (within 1 km) placed same low-Earth orbit at large distance (about 100 from transmitter. Each receiver is conceived to fit 12-unit CubeSat. A signal model adapted proposed geometry also presented, and corresponding processing scheme achieve range swath widening signal-to-noise ratio (SNR) improvement illustrated discussed.

We present an analytical formulation of the correlation electromagnetic fields scattered by a rough or gently undulating surface and measured at two spatially separated points. The latter may be positions different bistatic radar sensors receiving field same time, as in synthetic aperture interferometry, occupied single moving receiver slightly times, Global Navigation Satellite System Reflectometry. scattering is modeled randomly rough, Kirchhoff Approximation employed to compute field....

Synthetic Aperture Radar (SAR) images are greatly affected by the speckle noise. In order to improve SAR data readability human interpreters and information extraction performed computer programs, a despeckling preprocessing step is mandatory. The authors recently presented algorithm based on priori knowledge of local topography. this paper, an experimental sensitivity analysis aforementioned conducted main results discussed. particular, filter against surface parameters scattering behavior...

Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation processing data by human users computer algorithms, respectively. Very recently, scattering-oriented version popular Block-Matching 3D (SARBM3D) filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter based on...