Rapid estimation of the range-doppler scattering function

Kay, S.; Doyle, Steven

doi:10.1109/tsp.2002.806579

Cited by 41 publications

(17 citation statements)

References 30 publications

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“…We also present results from simulation and sea trials that illustrate excellent detection performance of the proposed design, in particular in comparison with the performance of a design using the more traditional approach to the Doppler estimation, based on computation of single-branch autocorrelation (SBA) [13], [17], [20]- [22], that ignores the acceleration.…”

Section: Introductionmentioning

confidence: 95%

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Zakharov

Henson

Diamant

et al. 2019

IEEE J. Oceanic Eng.

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In underwater acoustic (UWA) communications, the propagated signal undergoes severe Doppler and multipath distortions. The Doppler estimation/compensation and channel estimation/equalization techniques required to deal with these distortions contribute significantly to the overall complexity of UWA modems. In this paper, we propose a data packet structure for high data rate transmission in time-varying UWA channels with the channel dynamic modelled by velocity and acceleration between the transmitter and receiver. The data packet consists of superimposed data and periodic pilot sequences. The superposition allows achievement of a high spectral efficiency for data transmission. The repeated pilot symbols allow the use of a low-complexity multi-branch autocorrelation method for coarse estimation of Doppler parameters related to the velocity and acceleration. To refine these estimates, we further propose a lowcomplexity fine Doppler estimator based on dichotomous iterations. We also present a low complexity frequency domain channel estimator exploiting the channel sparsity. The proposed modem design has been evaluated using simulation and practical sea trials. The experiments demonstrate high detection performance of the proposed design, in particular in comparison with a more traditional design that ignores the acceleration between the transmitter and receiver.

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Section: Introductionmentioning

confidence: 95%

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Zakharov

Henson

Diamant

et al. 2019

IEEE J. Oceanic Eng.

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“…The continuously recorded CIRs compose bitemporal ionospheric response (BTIR) [Bello, 1963;Chong et al, 2000]. BTIR is converted into channel scattering function (CSF) in the frequency The characters of the return, diffuse, multimode and multipath composition are also usually evident from an examination of CSF [Gaarder, 1968;Kay and Doyle, 2003].…”

Section: Testing Systemmentioning

confidence: 99%

Almost perfect sequences applied for ionospheric oblique backscattering detection

Chen

Zhao

et al. 2009

Radio Science

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[1] Pseudorandom sequences are often used in radio systems; however, the nonzero out-of-phase autocorrelation of many binary sequences induces range sidelobes which significantly reduce the echo signal-to-noise ratio (SNR). In this paper, the use of almost perfect sequences, exhibiting zero out-of-phase autocorrelation except one value in the middle is examined with reference to common m sequences and perfect sequence. The ambiguity functions demonstrate that it is possible to use the almost perfect sequences for ranging without sidelobes and that their Doppler measurement performance is similar to m sequence of the same length. This is an important result for ionospheric oblique backscattering detection where the echoes are superposed and where range sidelobes can submerge the main lobes of weak signals. The 124-bit almost perfect sequence and the 127-bit m sequence are applied to the Wuhan Ionospheric Oblique Backscattering Sounding System for sequence testing. The test results have proven that the almost perfect sequence exhibits a higher echo SNR for the same detection conditions.

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“…Because scattering function estimation is a fundamental component of waveform design problems, it is a topic that has been studied for decades [30][31][32][33][34][35][36][37][38][39][40][41]. However, analytic expressions for scattering functions of sea clutter for airborne radars have not been reported in the literature except for some initial work by the author [1,42,43].…”

Section: Introductionmentioning

confidence: 99%

Analytic Expressions for Radar Sea Clutter WSSUS Scattering Functions

Cooke¹

2019

Entropy

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Bello’s stochastic linear time-varying system theory has been widely used in the wireless communications literature to characterize multipath fading channel statistics. In the context of radar backscatter, this formulation allows for statistical characterization of distributed radar targets in range and Doppler using wide-sense stationary uncorrelated scattering (WSSUS) models. WSSUS models separate the channel from the effect of the waveform and receive filter, making it an ideal formulation for waveform design problems. Of particular interest in the radar waveform design community is the ability to suppress unwanted backscatter from the earth’s surface, known as clutter. Various methods for estimating WSSUS system functions have been studied in the literature, but to date no analytic expressions for radar surface clutter range-Doppler scattering functions exist. In this work we derive a frequency-selective generalization of the Jakes Doppler spectrum model, which is widely used in the wireless communications literature, adapt it for use in radar problems, and show how the maximum entropy method can be used to extend this model to account for internal clutter motion. Validation of the spectral and stationarity properties of the proposed model against a subset of the Australian Ingara sea clutter database is performed, and good agreement is shown.

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Rapid estimation of the range-doppler scattering function

Cited by 41 publications

References 30 publications

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Data Packet Structure and Modem Design for Dynamic Underwater Acoustic Channels

Almost perfect sequences applied for ionospheric oblique backscattering detection

Analytic Expressions for Radar Sea Clutter WSSUS Scattering Functions

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