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This paper proposes a scattering model based segmentation technique for polarimetric synthetic aperture radar (PolSAR) images. The method is composed of two main parts: merging predicate and merging order. The merging predicate is based on the idea of the fractal network evolution algorithm (FNEA). The heterogeneity of the scattering characteristics between adjacent regions is calculated to judge...
Vegetation coverage is an important indicator for forecasting geological disasters in mountainous areas such as landslide. However, it is a challenge to extract vegetation coverage in complex terrain from SAR image. A major problem is that the variation of the backscatter coefficient of the same object varies with the local incidence angle. As a result, a large number of discrete points appear in...
A simple target scattering model is developed integrating the shape factor and geometric randomness that are less influenced by the SAR configuration, dielectric properties of crop, and the underlying soil conditions, to describe the shape and statistical distribution of the targets, respectively. 47 fully polarimetric RADARSAT-2 images in FQ1W, FQ6W, FQ10W, FQ15W and FQ19W modes with different incidence...
This paper describes a new technique for generating bistatic sea clutter returns based on the compound K-distribution model for clutter amplitude statistics. The technique adopts the computational electromagnetic (CEM) method to calculate bistatic sea clutter reflectivity by the given bistatic geometrical relationship, aiming at obtaining the parameters of the distribution. Then the theory of spherically...
This paper examines the potential impacts of remote sensing, hyperspectral target detection from a physics-based modeling point of view. Often (atmospherically compensated) data is simply handed off to algorithm developers with the assumption that the data they are given accurately represents what transpired at the time of collection. In this paper, we discuss the various steps involved in processing...
Estimating the characteristics of the snow cover is essential for managing hydroelectric dams and forecasting rises in water level in the spring. For the estimation of the Snow Water Equivalent (SWE) at fine scale and to make connections with the hydrology of small watershed, it is necessary to turn towards active microwave sensors like Synthetic Aperture Radar (SAR). This paper gives an overview...
A fully coherent snowpack scattering and emission model is developed by numerically solving Maxwell's equations over the entire snowpack on a bottom half-space. The scattering matrix of the snowpack is directly obtained including both amplitude and phase. Both bistatic scattering coefficients and brightness temperatures of the snowpack are derived from full wave simulations. Simulation results demonstrate...
Microwave back and forward scattering from a layer of vegetation continues to have important applications in remotely sensing soil moisture and vegetation biomass. Satellite radars detect backscattered returns while GNSS receivers can measure forward scatter. The scattering cross sections can be computed by the Distorted Born Approximation (DBA) and by 1st order transport theory. The first is a field...
A polarimetric scattering model for inhomogenenous layer with vertical profile is applied to analyze backscattering from soil layer at L-band. The soil layer is modeled as discrete random medium with water content that varies with depth and bounded by randomly rough surfaces. The soil is modeled as air voids embedded in host medium consisting of a mixture of solid minerals and water. The air-soil...
A modeling study investigating the influence of wind direction on spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) near specular observations of the sea surface is reported. Because the delay doppler maps (DDMs) measured in GNSS-R include some non-specular contributions even for “specular” portions of the DDM, the study performs an examination of near specular DDM variations with...
With the current and planned scientific missions related to ocean observation, there is a need to understand the relevant scattering physics and sensitivity so as to provide a physical basis for retrieving geophysical information from ocean-scattered signals. Sea spectrum is one of the factors to be determined in the retrieval. Since difference in sea spectrum manifests itself mostly at sea waves...
Traditionally, Radiative Transfer (RT) formulation has been used to simulate scattering from snow layer with the incorporation of phase matrix of scatterers in the formulation. Typically, spherical scatterers were assumed to represent the ice particles embedded inside the air medium and Mie phase matrix was applied. However, the real scatterers in the actual snow are generally more irregular than...
This paper presents a comprehensive reappraisal of the scattering, both backscattering and bistatic scattering, and emission of rough soil surface predicted by a well-established theoretical model, the advanced integral equation model (AIEM). Extensive numerical data simulated by approximate and numerically exact models as well as experimental datasets of well-characterized bare soil surfaces were...
This paper will discuss recent improvements made to the Monte Carlo Scene (MCScene) code to enable limb-viewing scenarios and situations where the sun is below the horizon. MCScene is a high-fidelity model for full optical spectrum (UV through LWIR) hyperspectral image (HSI) simulation. MCScene generates HSI scenes for algorithm validation, utilizing a Direct Simulation Monte Carlo (DSMC) approach...
Approximate radiative transfer model solutions have been developed by Hapke [1][2]. Important geophysical parameters such as density and grain size distribution play an important role in parameterizing these solutions, however the radiative transfer solutions are typically nonlinear functions of these important parameters. We have developed a method which isolates single scattering properties of the...
We challenge the often-made claim that fully polarimetric synthetic aperture radars (SARs) are beneficial for discriminating between mineral oil films and biogenic slicks. We conjecture that the results obtained from previous analyses of spaceborne polarimetric SAR data, which seem to show differences in the scattering mechanism between radar scattering from mineral oil films and biogenic slicks,...
This paper considers techniques of aspect feature extraction and application of targets taken over one or more wide-angle apertures. Compared with traditional narrow-aperture Synthetic Aperture Radar (SAR), multi-aspect SAR can provide observation of targets in more azimuth directions. Radar backscattering is typically characterized by location and azimuth directions. Thus target anisotropic scattering...
In this paper, a new algorithm for ship detection with Synthetic Aperture Radar (SAR) images is presented. We develop the proposed method by combing Principal Component Analysis (PCA) and the Geometrical Perturbation-Polarimetric Notch Filter (GP-PNF) method. In the first step, we replace the feature vector composed by the elements of the covariance matrix with more polarimetric features. Then, PCA...
Synthetic aperture radar is used to identify and monitor oil spills. Separation from oil spill look-alikes is an important part of a fully automatic oil spill detection scheme. Here we investigate the polarimetric signatures for oil spills and newly formed sea ice (a well-known look-alike) in fully polarimetric Radarsat-2 satellite scenes. Using the fully polarimetric scenes we calculate four different...
In this paper, a new algorithm for detecting ship and removing azimuth ambiguities is presented. The proposed method is developed by combing the third eigenvalue and the Geometrical Perturbation-Polarimetric Notch Filter (GP-PNF) methods. We firstly improve the GP-PNF feature vector with the third eigenvalue calculated by the eigenvalues-eigenvector decomposition method. Then, the new feature vector...
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