Polarimetric radar measurements were conducted for bare soil surfaces under a variety of roughness and moisture conditions at L-, C-, X-band frequencies incidence angles ranging from 10 degrees to 70 . Using laser profiler dielectric probes, complete accurate set ground truth data was collected each surface condition, which made the rms height, correlation length, constant. Based on knowledge scattering behavior in limiting cases experimental observations, an empirical model developed sigma...

A semiempirical polarimetric backscattering model for bare soil surfaces is inverted directly to retrieve both the volumetric moisture content M/sub v/ and rms surface height s from multipolarized radar observations. The can be read inversion diagrams using measurements of cross-polarized coefficient /spl sigma//sub vh//sup 0/ copolarized ratio p(=/spl hh//sup 0///spl vv//sup 0/). Otherwise, parameters estimated simply by solving two equations (/spl p) in unknowns (M/sub s). technique has...

A semi-empirical model of the ensemble-averaged differential Mueller matrix for microwave backscattering from bare soil surfaces is presented. Based on existing scattering models and data sets measured by polarimetric scatterometers JPL AirSAR, parameters co-polarized phase-difference probability density function, namely degree correlation /spl alpha/ sigmav/, in addition to coefficients sigma//sub nu//spl nu///sup 0/,/spl hh//sup 0/ nu/h//sup 0/, are modeled empirically terms volumetric...

Whereas it is well known that electromagnetic scattering by a randomly rough surface strongly influenced the surface-height correlation function, not clear as to how long profile needed and at what interval should be sampled experimentally quantify function of real surface. This paper presents results Monte Carlo simulation conducted answer these questions. It was determined that, in order measure rms height length with precision /spl plusmn/10%, segment least 40l 200l long, respectively,...

Biomass estimation of eastern Mediterranean shrublands was investigated using PALSAR full- and dual-polarization L-band Sentinel-1 C-band data. First, we conducted an empirical assessment single multiple regressions between polarized backscattering coefficients shrubland biomass distribution along the climatic gradient semiarid arid regions. We then found that HV-polarized coefficient has higher information content than Based on a theoretical volume scattering model semiempirical model,...

This paper presents the development of an accurate and simple scattering model for radar backscatters agricultural fields. We modified water-cloud (WCM) by adding new parameters (the average standard deviation leaf angle distribution) to accurately estimate backscattering coefficients with angular effect particles in a vegetation canopy. A relatively radiative transfer (RTM) field measurements were used this modification. The accuracy RTM was verified C-band ground-based scatterometer data...

A semi-empirical polarimetric scattering model for bare soil surfaces is developed. This constructed based on the existing theoretical models in conjunction with an extensive experimental data collected scatterometer systems at microwave frequencies. The backscattering coefficients as well parameters of phase difference statistics, degree correlation (/spl alpha/) and polarized zeta/), are expressed terms both surface (rms height, length, dielectric constant) radar (frequency incidence...

The polarimetric backscattering coefficients (vv-, hh-, hv-, and vh-polarizations) of a flooded rice field are measured using L- C-band ground-based scatterometers. These measurements were made during the growth cycle, i.e., from transplanting period to harvest (May October 2006), understand feasibility modeling estimating growth. We also collected ground truth data that include fresh dry biomasses, plant height, leaf area index, size. To study incidence angle effect, scatterometer at four...

This paper presents an examination of classical scattering models for radar cross sections deciduous leaves, such as the generalised Rayleigh-Gans (GRG) model and physical optics (PO) model. The PO employs resistive sheet approximation in this study. validity regions analytical microwave from leaves are investigated by comparison with precise numerical results method moment. It was found that GRG extend their estimating amplitudes thickness a lossy dielectric disk decreases. can be used...

Polarimetric radar backscattering measurements of a variety powerline cables are presented. The objective the first part investigation was to study effect braiding on at skew incidence. were performed for four different actual size samples C-, X-, and Ka-band over wide range incidence angles. data collected 500 MHz bandwidth C- X-band with 1.25 increment 1 GHz 2.5 increment. Also nonuniform illumination measurement in near field studied. Experimental shows significant backscatter...

A rigorous method is presented for calibrating polarimetric backscatter measurements of distributed targets. By characterizing the radar distortions over entire mainlobe antenna, differential Mueller matrix derived from measured scattering matrices with a high degree accuracy. It shown that can be determined by measuring response metallic sphere main lobe antenna. The are categorized as caused active devices or antenna structure (passive). Since passive immune to changes once they...

A new inversion algorithm was developed to determine the surface roughness and soil moisture content of a bare from temporal data set single-polarized radar measurements. This is simple as it based on well-known empirical scattering model, thereby avoiding time-consuming training. For (VV-, HH-, or VH-polarization) measurements, possible combinations root-mean-square (rms) height (hrms) contents (Mv) for each measurement were first computed using all results then juxtaposed in an hrms - Mv...

Biomass is a critical biophysical parameter used to monitor agricultural and terrestrial ecosystems. Operational difficulties in measuring biomass on the field scale led use of remote sensing techniques. Numerous vegetation indices (VIs) have been developed for this purpose, most which utilize bands VIS-NIR spectral region. However, significant number them exhibit saturation at leaf area index (LAI) higher than 2. We propose an innovative red-edge ratio normalized difference (RERNDVI), that...

The root mean square (rms) height s and autocorrelation length l are commonly used as the surface roughness input parameters to scattering models. Whereas it is well known that of a natural soil underestimated with short profile, not clear how much affect backscattering coefficients for various incidence angles polarizations. In this paper, simulated measured profiles computed using integral equation method analyzed answer question. A 4000lmacr-long rough generated numerically, where lmacr...

Several topics associated with the use of a polarimetric active radar calibrator (PARC), which is high radar-cross-section transponder known scattering matrix, are addressed. The first involves experimental measurements magnitudes and phases scattering-matrix elements pair PARCs that operate at 1.25 GHz 5.3 GHz. were conducted over wide range incidence angles (relative to boresight direction) in azimuth, elevation, 45 degrees , 135 planes. 5.3-GHz PARC, consisted two antennas placed several...

An efficient numerical solution for the scattering problem of inhomogeneous dielectric rough surfaces is presented. The random surface represents a bare soil and considered to be comprised large number randomly positioned humps different sizes, shapes, constants above an impedance surface. Clods with nonuniform moisture content rocks are modeled by underlying smooth wet In this technique, constituent over obtained using Green's function derived exact image theory in conjunction method...

A Monte Carlo simulation of electromagnetic scattering from one-dimensional perfectly conducting random surfaces is considered in the paper. Surface profiles desired statistics are generated numerically using a standard procedure and solution for surface samples finite length calculated method moments. new technique used to reduce effect edges samples. In this technique, conductivities near controlled by adding an appropriate tapered resistive sheet. It shown that accuracy at large angles...

When point calibration targets are used to calibrate a SAR image, the accuracy is governed by two major factors. The first factor stems from stringent requirement on radar cross section (RCS) of target. To reduce effect return background, RCS target must be much larger than that background. Calibration with large require physical dimensions for passive or high amplifier gain active targets, which in practice leads uncertainty nominal targets. second related fact develop algorithm applied...

This paper presents the results of polarimetric measurements for bare soil surfaces under a variety roughness and moisture conditions. The were performed at L-, C-, X-band over wide bandwidth to increase number independent samples. For each surface condition, data collected incidence angles ranging from 10 70. Including samples provided measured bandwidth, angle more than 1000 acquired generate statistics radar returns. Using laser profiler dielectric probes, complete accurate set ground...

A full-wave solution for polarimetric scattering from a cluster of randomly oriented three-dimensional lossy dielectric structures above an impedance surface is presented to investigate the importance multiple scattering. The problem formulated using integral equation in conjunction with exact image representation dyadic Green's function half-space problem. Then, solved induced equivalent polarization currents method moments. accuracy numerical code verified other existing results and...

We present a compact L-band orthomode transducer (OMT) with new waveguide junction consisting of quad-ridged square and four single-ridged triangular waveguides. Quad-ridged waveguides various sizes were numerically analyzed to estimate the cutoff frequencies characteristic impedances An optimum structure for OMT low frequency specific impedance was found based on numerical simulation. The has relatively small size without branches, provides good matching 50 Ω coaxial feed line. In addition,...

A robust inversion technique using a genetic algorithm (GA) for retrieving soil moisture content from the multi-polarised radar data of bare surfaces is presented. This employs semi-empirical polarimetric backscattering model as cost function GA. Good agreement found between values estimated by this and those measured in situ.