Multidimensional maximum-likelihood processing of a large aperture seismic array

Capon, Jack; Greenfield, Roy J.; Kolker, R.J.

doi:10.1109/proc.1967.5439

Cited by 249 publications

(118 citation statements)

References 9 publications

Supporting

Mentioning

116

Contrasting

Unclassified

Order By: Relevance

“…another expression for the spectral energy density matrix can be found, which is characteristic for the beamforming method introduced by Capon et al (1967):…”

Section: The Field Line Resonance Detectormentioning

confidence: 99%

“…The wave telescope is an array signal processing technique, also known as Capon beamformer, which was introduced by Capon et al (1967) and Capon (1969) for the analysis of seismic waves. Essentially, this technique is a high resolution estimator for the spectral field energy density of a wave field measured at a sparse array of stations with good temporal resolution.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Statistical analysis of ground based magnetic field measurements with the field line resonance detector

et al. 2008

View full text Add to dashboard Cite

Abstract. In this paper we introduce the field line resonance detector (FLRD), a wave telescope technique which has been specially adapted to estimate the spectral energy density of field line resonance (FLR) phase structures in a superposed wave field. The field line resonance detector is able to detect and correctly characterize several superposed FLR structures of a wave field and therefore constitutes a new and powerful tool in ULF pulsation studies. In our work we derive the technique from the classical wave telescope beamformer and present a statistical analysis of one year of ground based magnetometer data from the Canadian magnetometer network CANOPUS, now known as CARISMA. The statistical analysis shows that the FLRD is capable of detecting and characterizing superposed or hidden FLR structures in most of the detected ULF pulsation events; the one year statistical database is therefore extraordinarily comprehensive. The results of this analysis confirm the results of previous FLR characterizations and furthermore allow a detailed generalized dispersion analysis of FLRs.

show abstract

“…another expression for the spectral energy density matrix can be found, which is characteristic for the beamforming method introduced by Capon et al (1967):…”

Section: The Field Line Resonance Detectormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Statistical analysis of ground based magnetic field measurements with the field line resonance detector

et al. 2008

View full text Add to dashboard Cite

show abstract

“…We therefore delegated the combination of the signals from multiple beams to this diversity receiver. 3 The maximum improvement to be gained by steering a second beam would have been the difference between selection combining (in our case angular selection diversity) and maximum ratio combining which amounts to 1.3 dB in SNR [9].…”

Section: ) Uplink Post Beamformermentioning

confidence: 96%

“…The third algorithm is a beamforming technique. Capon's Beamformer [3], also known as Minimum Variance Method (MVM), minimizes the power contribution from noise and any signals coming from other directions than , while maintaining a fixed gain into the direction .…”

Section: A Doa Estimationmentioning

confidence: 99%

A real-time DOA-based smart antenna processor

Kuchar

Tangemann

Bonek

2002

IEEE Trans. Veh. Technol.

View full text Add to dashboard Cite

Abstract-We designed, built, and tested a real-time processor for a direction-of-arrival-based smart antenna GSM 1800 base station with eight half-wavelength spaced antenna elements. Its processing steps include direction-of-arrival (DOA) estimation, user identification, tracking, beamforming, and signal reconstruction. We demonstrate that the accuracy of DOA estimation is not of primary concern, but the robustness is. This can be assessed by a new parameter, the estimation range. Tracking of reliable user DOAs only, increases the robustness against interference. Our tracking concept is compatible with frequency hopping. We quantify the benefits of smart antennas by the statistics of the gain in carrier-tointerference ratio (C/I) and in signal-to-noise ratio (SNR), both measured at the 90 or 99% levels with actual transmitted data. In an urban environment with large angular spread and overlap of user and interferer signals, the C/I gain is as high as 18 dB. Interferer nulling increases the C/I gain only slightly, but enhances robustness against angular spread, particularly if broad nulls are applied. Separating SNR gain in its contributions due to beamforming and diversity gives valuable insight into the way of operation. In uplink, the processor can exploit angular diversity. The entire suite of processing steps is done within less than 1 ms, demonstrating that sophisticated DOA-based smart antenna processing is feasible in real time. Our solution does not require any change in the GSM standard.Index Terms-Angular diversity, carrier-to-interference ratio (C/I) improvement, component angular spread, direction-of-arrival estimation, smart antenna, wireless communications.

show abstract

“…To extract surface wave dispersion curves, Aki (1957) proposed the spatial autocorrelation (SPAC) method, which has been generalized to the extended spatial autocorrelation method by Ohori et al (2002). Further methods use different transforms and they obtain similar results, for example, the slant-slack transform (McMechan & Yedlin 1981), the frequency-wavenumber analysis (maximum likelihood method, Capon et al 1967;Capon 1969;Horike 1985) and the multichannel analysis of surface waves Park et al 1999).…”

Section: Data P Ro C E S S I N Gmentioning

confidence: 99%

A 3D algorithm based on the combined inversion of Rayleigh and Love waves for imaging and monitoring of shallow structures

2017

View full text Add to dashboard Cite

S U M M A R YIn recent years, there has been increasing interest in the study of seismic noise interferometry as it can provide a complementary approach to active source or earthquake-based methods for imaging and continuous monitoring the shallow structure of the Earth. This meaningful information is extracted from wavefields propagating between those receiver positions at which seismic noise was recorded. Until recently, noise-based imaging relied mostly on Rayleigh waves. However, considering similar wavelengths, a combined use of Rayleigh and Love wave tomography can succeed in retrieving velocity heterogeneities at depth due to their different sensitivity kernels. Here, we present a novel one-step algorithm for simultaneously inverting Rayleigh and Love wave dispersion data aiming at identifying and describing complex 3-D velocity structures. The algorithm may help to accurately and efficiently map the shear wave velocities and the Poisson ratio of the surficial soil layers. In the high-frequency range, the scattered part of the correlation functions stabilizes sufficiently fast to provide a reliable estimate of the velocity structure not only for imaging purposes but also allows for changes in the medium properties to be monitored. Such monitoring can be achieved with a high spatial resolution in 3-D and with a time resolution as small as a few hours. In this paper, we describe a recent array experiment in a volcanic environment in Solfatara (Italy) and we show that this novel approach has identified strong velocity variations at the interface between liquids and gas-dominated reservoirs, allowing localizing a region which is highly dynamic due to the interaction between the deep convection and its surroundings.

show abstract

Multidimensional maximum-likelihood processing of a large aperture seismic array

Cited by 249 publications

References 9 publications

Statistical analysis of ground based magnetic field measurements with the field line resonance detector

Statistical analysis of ground based magnetic field measurements with the field line resonance detector

A real-time DOA-based smart antenna processor

A 3D algorithm based on the combined inversion of Rayleigh and Love waves for imaging and monitoring of shallow structures

Contact Info

Product

Resources

About