Abstract Understanding climate change impacts on hydrological regime and assessing future water supplies are essential to effective resources management planning, which is particularly true for the Tibetan Plateau (TP), one of most vulnerable areas change. In this study, in TP was projected 2041–2060 by a high‐resolution regional model, RegCM4, under 3 representative concentration pathways (RCPs): 2.6, 4.5, 8.5. Response all key elements, that is, evapotranspiration, surface run‐off,...

A complete facet model for the backscattering from rough sea surface with breaking waves is proposed in this paper. In consideration of spatial distribution on surface, able to give a good interpretation "super events" under high states, such as spikes and polarization ratios. Based model, normalized radar cross section plots configuration are calculated compared measured data. The comparisons show that tractable estimate scattering electrically large ocean states accuracy efficiency....

A modified range-Doppler algorithm (M-RDA) for processing high squint synthetic aperture radar (SAR) echoes is proposed in this letter. Unlike the original RDA, M-RDA directly corrects range cell migration frequency domain without interpolation, which greatly enhances its computational efficiency. When analyzing a SAR echo signal, approximation of distance between antenna and scene interest leads to error azimuthal compression. To address problem, fourth-order phase model considered achieve...

An improved facet model for the predication of normalized radar cross section (NRCS) electrically large rough sea surface was proposed based on first-order small slope approximation (SSA-1) method, Bragg scattering mechanism, and specular mechanism. The method is able to evaluate both complex reflective function NRCS surfaces from as low ultrahigh frequency band high Ka-band. main idea that a tilt can be regarded superposition planner microscopic profile; latter assumed set sinusoidal ripple...

In this article, an automatic method is proposed for ship velocity estimation based on the two-dimensional spectrum pattern of Kelvin wakes in synthetic aperture radar (SAR) images which effectiveness proved with both simulation and experimental results. The has following advantages. First, can be estimated automatically, will not introduce extra error caused by manual operations. Second, prior knowledge SAR parameters needed only factor that matters pixel spacing image. Then, effects speed,...

Differences in the motion of different parts a target cause echo signal to contain specific Doppler modulation information, i.e., micro-Doppler (m-D) effect. This phenomenon provides an effective way detect targets marine environments. In this study, based on establishment micromotion model rotating surveillance radar and analysis m-D frequency, geometrical optics physical (GO-PO) method time-frequency technique are used obtain cross section (RCS) signature ship with shipborne at observation...

The small slope approximation (SSA) is a widely employed way to analyse the electromagnetic (EM) scattering problems from rough surfaces. However, it requires surface sampling interval less than one‐eighth of wavelength, which makes suffer large memory consumption and low calculation efficiency for surfaces, especially higher microwave bands. In this study, new generate electrically surfaces proposed its application EM field introduced on base first‐order SSA. accuracy consumed computer...

A reliable and efficient way is proposed for investigating the electromagnetic (EM) scattering from a large marine environment containing multiple vessels. To enhance computational efficiency, an improved method based on facet-based simplified small slope approximation to calculate field sea surface. In addition, overall surface decomposed into noncoupled coupled regions. Then, this letter uses combined geometrical optics/physics optical physical theory of diffraction studying targets...

Memoryless nonlinear transform (MNLT) method was widely used in the statistical model for sea clutter simulations. When radar scattering data sets were obtained, we can simulate large scene and long-time varying 3-D surface using expended power spectral quickly accurately. Compared with personal computer platform, field-programmable gate array (FPGA) has unique merit of energy efficiency, high performance adaptability. In this article, proposed a novel architecture implementing MNLT...

To investigate highly squinted spotlight synthetic aperture radar (SAR) images of an electrically large ship target over a rough sea surface, this work focuses on the simulation analysis SAR from such composite scene. For problem, there are two key issues need to be considered, namely and processing echoes. Considering first issue, efficient facet scattering model based capillary wave modification geometrical optics physical hybrid method is applied calculate electromagnetic (EM)...

A full-polarized facet based scattering model (FPFSM) for investigating the electromagnetic (EM) by two-dimensional electrically large sea surfaces with high efficiency at microwave bands is proposed. For this method, field over a in diffuse region numerically deduced according to Bragg mechanism. In regard near specular directions, novel approach proposed calculate scattered from surface on second order small slope approximation (SSA-II), which saves computer memory considerably and able...

With the realization of global navigation satellite system (GNSS) completion, GNSS reflectometry (GNSS-R) has become increasingly popular due to advantages coverage and availability multiple sources in terms earth remote sensing. This paper analyzes Beidou (BDS) signal reflection detection satellites moving targets under multiple-input multiple-output (MIMO) radar systems proposes a series methods suppress Doppler phase influences improve range property. The simulation results show restored...

In this paper, a combination of the geometrical optics and physical (GO/PO) hybrid method theory diffraction (PTD) is presented for analyses electromagnetic (EM) scattering SAR imaging simulation from complicated electrically large target. For method, field surfaces on target calculated with GO/PO PTD. Then contribution targets different shapes are analyzed. It shown that wedges composed two nearly mutually perpendicular flat surface, much strong than edges. Otherwise, must be taken into...