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3 edition of Estimation of the rain signal in the presence of large surface clutter found in the catalog.

Estimation of the rain signal in the presence of large surface clutter

Estimation of the rain signal in the presence of large surface clutter

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Published by University of Kansas Center for Research, Inc., Radar Systems and Remote Sensing Laboratory, National Aeronautics and Space Administration, National Technical Information Service, distributor in Larwence, Kansas, [Washington, DC, Springfield, Va .
Written in English

    Subjects:
  • Satellite meteorology.

  • Edition Notes

    StatementAtiq Ahamad and Richard K. Moore.
    Series[NASA contractor report] -- NASA CR-195105., NASA contractor report -- NASA CR-195105.
    ContributionsMoore, R. K., United States. National Aeronautics and Space Administration.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL14704805M

      Ebenezer, SP & Papandreou-Suppappola, A , ' Low RCS Target Tracking in Estimated Rapidly Varying Sea Clutter Using a Kronecker Product Approximation Algorithm ', IEEE Journal on Selected Topics in Signal Processing, vol. 9, no. 8, , pp. Cited by: 4. Oceanic ambient noise measurements can be analyzed to obtain qualitative and quantitative information about wind and rainfall phenomena over the ocean filling the existing gap of reliable meteorological observations at sea. The Ligurian Sea Acoustic Experiment was designed to collect long-term synergistic observations from a passive acoustic recorder and surface sensors (i.e., buoy mounted Cited by: 9. In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process.A fading channel is a communication channel that experiences fading. In wireless systems, fading may either be due to multipath propagation, referred to as multipath-induced. Bistatic Surface Clutter Resolution Area at Small Grazing Angles [Melvin M. Weiner] on *FREE* shipping on qualifying offers.


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Estimation of the rain signal in the presence of large surface clutter Download PDF EPUB FB2

Signals may be estimated in the presence of noise by averaging large numbers of independent samples. This method was applied to obtain an estimate of the rain echo by averaging a set of N(sub c) samples of the clutter in a separate measurement and subtracting the clutter estimate from the combined : Richard K.

Moore and Atiq Ahamad. Get this from a library. Estimation of the rain signal in the presence of large surface clutter. [Atiq Ahamad; R K Moore; United States. National Aeronautics and Space Administration.]. (a) Ray trace hit pattern, (b) return clutter power, and (c) ray density for mixed land/sea terrain profile shown in Figure 1a, in the presence of a m surface‐based by: Surface clutter includes trees, vegetation, ground terrain, man-made structures, and sea sur-face (sea clutter).

Volume clutter normally has a large extent (size) and includes chaff, rain, birds, and insects. Surface clutter changes from one area to another, while volume clutter may be more predictable. Clutter echoes are random and have File Size: KB.

Surface clutter echoes through antenna and range sidelobes from pulse compression can severely interfere with the atmospheric radar returns near the earth surface. A radar simulator is developed to study the impacts of clutter interference from different types of earth surface.

Simplified antenna pattern and pulse compression filter. Sea clutter is the main interfering signal in radar systems. In order to develop appropriate strategies for clutter suppression, an algorithm able to identify the distribution of radar readings.

Refractivity estimation from sea clutter: An invited review Ali Karimian,1 Caglar Yardim,1 Peter Gerstoft,1 William S. Hodgkiss,1 and Amalia E. Barrios2 using its sea surface reflected clutter signal. The knowledge of the refractivity structure enables radar operators to com-pensate for non‐standard atmospheric effects, or at least beFile Size: 1MB.

frequency that determine the signal pattern (clutter as a function of range). (2) Sea clutter parameters (c s) such as surface roughness, wind strength and direction, clutter statistics type, and clutter probability density function (pdf) parameters that determine the fluctuations in the received clutter signal.

The interaction between each of. The basic types of clutter can be summarized as follows: Surface Clutter Sea Clutter Surface Clutter Ground or sea returns are typical surface clutter. Returns from geographical land masses are generally stationary, however, the effect of wind on trees etc means that the target can introduce a.

Start studying Sensation and Perception Ch1,2,3,5. Learn vocabulary, terms, and more with flashcards, games, and other study tools. A psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of noise; stimulus you're trying to detect (signal) is always being detected in the presence.

Other approaches have been described in the literature for estimating the level of different clutter sources without needing the use of sophisticated models.

For example, rain and sea clutter estimations have been made by simple models based on sea state and significant wave heights parameters [26].

the presence of clutter. In this paper, we present a method that uses a fully convolutional neural network (FCNN) in conjunction with a novel optimization framework for gener-ating layout estimates.

We demonstrate that our method is robust in the presence of clutter and handles a wide range of highly challenging scenes. We evaluate our method on. events encountered in Europe. The rain events include two cold frontal rainbands with average rainfall rates of 7 and 17 mm h 1, respectively, and two summertime convective rain events with average rainfall rates of 11 and 22 mm h 1.

The large effects of beam shielding on rainfall accumulation were observed for algorithms using Z h and Z. range, creation of radar holes where the radar is effectively blind, target altitude errors and large sea surface clutter due to the increased interaction between the electromagnetic signal trapped within the duct and the sea surface.

Refractivity from clutter (RFC) refers to techniques that estimate the atmospheric refractivity. Time Delay Ranging. • Target range is the fundamental quantity measured by most radars.

It is obtained by recording the round trip travel time of a pulse, TR, and computing range from: where c = 3x m/s is the velocity of light in free Size: 2MB.

Fig. 12 is a plot of the mean value of σ° for sea clutter as a function of the grazing angle. It applies for a medium sea (10–20 knot winds). At the lower grazing angles, sea clutter increases slowly with increasing winds above 15 to 20 knots (a few tenths of a decibel per knot). Below about 5.

graz is the grazing angle of the clutter patch relative to the radar. tau is the pulse width of the transmitted signal. The calculation automatically determines whether the surface clutter area is beam limited or pulse limited, based on the values of the input arguments.

DSP APPLICATIONS IN RADAR vatsala () Supervisor: Dr Vikram M. Gadre, Associate Professor Abstract There has been an explosive growth in Digital Signal Processing theory and applications over the years. This seminar report explores the applications of digital signal.

For sea clutter, and assuming a flat earth, the fact that its RCS is proportional to range effectively means that the R 4 term in the radar equation reduces to R 3, simply because the RCS (σ) should now be represented by R×σ s, where σ s is a fixed quantity, effectively representing the.

The signal received by radar contains reflections from various objects besides the intended targets, such as land, clouds, rain, and the sea surface. All such undesired re-flections from non-targets are referred to as clutter.

The presence of this sort of clutter can result in false detec-tion of targets or undetected targets, and is a major ob.

Factors affecting radar performance. The performance of a radar system can be judged by the following: (1) the maximum range at which it can see a target of a specified size, (2) the accuracy of its measurement of target location in range and angle, (3) its ability to distinguish one target from another, (4) its ability to detect the desired target echo when masked by large clutter echoes.

This reflected signal is then received by the radar during its listening period. Computers analyze the strength of the returned pulse, time it took to travel to the object and back, and phase, or doppler shift of the pulse.

This process of emitting a signal, listening for any returned signal, then. CurryR˙book Rain Loss 73 0 1 2 1, signal path. Since only liquid rain produces significant attenuation, only perfectly-reflecting surface, the re-ceived signal varies between zero and 16 times the signal level from theFile Size: KB.

Keywords: Optimal detection algorithm, SAR, clutter suppression 1 Introduction The forming problem of the optimal algorithm for signal detection in the radar with synthesized aperture (SAR) under the presence of the clutter re ec-tions from the local objects and the design of the e ciency estimation.

Problems in calculating signal to volume clutter ratio. A problem with volume clutter, e.g. rain, is that the volume illuminated may not be completely filled, in which case the fraction filled must be known, and the scatterers may not be uniformly distributed. Consider a beam 10° in elevation. sufficiently large dynamic range to allow for the clutter rejection to be implemented on the digital side.

The Doppler signal is modeled as the summation of the true velocity signal, a clutter component, and a random noise component. To simplify the analysis, the first two components are assumed as deterministic yet unknown signals.

We formulate and solve a new parameter estimation problem in the presence of data uncertainties. The new method is suitable when a priori bounds on the uncertain data are available, and its solution leads to more meaningful results, especially when compared with other methods such as total least-squares and robust by: Macroburst: Large downburst with 4 km ( nmi) or larger outflow size with damaging wind lasting 5 to 20 minutes.

Maximum Expected Hail Size (MEHS): A radar algorithm that computes the maximum expected hail size. MESH usually overestimates the maximum size of hail that will reach the earth's surface. The PIA in a raining scene can, therefore, be estimated as the difference between the observed surface return and the equivalent clear-sky value based on wind speed and SST.

Although the retrieval uses the PIA to estimate the rain rate, rainfall detection is based on the attenuation-corrected reflectivity in the lowest clutter-free by: This book provides an authoritative account of the current understanding of radar sea clutter, describing its phenomenology, EM scattering and statistical modelling and simulation, and their use in the design of detection systems and the calculation and practical evaluation of radar book pays particular attention to the compound K distribution model developed by the authors.

The rain estimation procedures given in Ryzhkov et al. (b) were used to calculate dual-polarization radar-based rainfall values according to the JPOLE optimization method. In this method, the magnitude of the rain rate given by the standard Weather Surveillance Radar Doppler (WSRD) R(Z h) formulation controls the selection of one of three rain-rate by: ANALYTIC METHODS FOR SAR IMAGE FORMATION IN THE PRESENCE OF NOISE AND CLUTTER By Huseyin C˘a gr Yan k A Dissertation Submitted to the Graduate Faculty of Rensselaer Polytechnic Institute in Partial Ful llment of the The Estimation of the.

the most effective clutter rejection capability for signals with small phase rotations. System model: A radar signal s(t) containing a static clutter and an echo from a moving target with a displacement of x(t) is modelled as s (t)= A exp jf + c N (1) f(t) = 4px(t) l (2) where t is the slow time, A is the amplitude of the desired signal, ϕ(t)is.

- B. Mériaux, X. Zhang, M. El Korso, M. Pesavento, "Iterative Marginal Maximum Likelihood DOD and DOA Estimation for MIMO Radar in the Presence of SIRP Clutter", Elsevier Signal Processing Journal, VolumeFebruaryPages THE MODELLING OF RADAR SEA CLUTTER 1.

Papers presented in the thesis The papers listed below are the subjects of this thesis. They are referenced by number in the supporting text and the full papers are appended to the thesis, labelled Paper 1, Paper 2 etc.

[1] K D Ward, C J Baker and S Watts, “Maritime Surveillance radar part 1: Radar. Signal Hill in Cape Town. This site provided azimuth coverage of from up- to cross-swell, but with only two predominant wind directions for the duration of the trial.

The sea was more representative of open sea conditions. Sea clutter and littoral clutter at grazing angles –10 were recorded. The experimental radar uses pulse compression to. Always be aware of possible crosstalk from another Sonar pinging at the same time Digital depth anomalies can sometimes be mis-interpreted as a surface clutter issue or a unit malfunction when often, simply turning on (and up) the "Noise Filter" under the Sonar tab of the affected unit can clear up the digital depth erratic behavior.

resolution signal processing algorithm cannot extract more information than is contained in the signal. The processing, proposed in this paper, is based on parametric estimation methods and uses autoregressive models for Doppler spectral is pointed out how a reliable model of sea clutter can be constructed, forFile Size: KB.

Chapter 3: Standard Radar Operations Adjusting Gain, Sea Clutter, Rain Clutter and Tune Automatic adjustment of Gain, Sea and Tune is available, alternatively you can set any of these parameters to manual and use the trackpad to adjust its value.

Rain clutter is adjusted manually using the RAIN. the surface. •Clouds and precipitation frequently consist of a variety of particle types (e.g., ice and rain). Each particle interacts with the radar's energy in its own unique way. As you’ve probably noticed, the precipitation estimates from radar data don’t always agree with rain gauges.

Meteorologists have been working on this problem. scattering signals from the sea surface called sea clutter, due to the interaction between electromagnetic waves and the sea surface.

In this paper, we will present a simulator that calculates the sea clutter spectrum from a coastal radar. This implies that sea clutter characteristics should be computed for low-grazing angles.Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects.

It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same.7 7/ Normalized RCS σ0 R Radar pulse Elevation R Azimuth h ψ Clutter patch antenna footprint φgr ρ θel θaz R θaz ρsec φgr The normalized clutter reflectivity, σ0, is defined as the total RCS, σ, of the scatterers in the illuminated patch, normalized by the area, A c, of the patch and it is measured in units of dBm 2/m 2.

local grazing angle.