Roy J. Greenfield

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Ž . We compare the ability of several practical ground-penetrating radar GPR array processing methods to improve Ž . signal-to-noise ratio SNR , increase depth of signal penetration, and suppress out-of-plane arrivals for data with SNR of Ž . Ž . roughly 1. The methods include two-dimensional 2-D monostatic, three-dimensional 3-D monostatic, and 3-D(More)
The distinguishing spatial properties of low-frequency microphone wind noise (turbulent pressure disturbances) are examined with a planar, 49-element array. Individual, propagating transient pressure disturbances are imaged by wavelet processing to the array data. Within a given frequency range, the wind disturbances are much smaller and less spatially(More)
This report presents an interim appraisal of capabilities of a single Large Aperture Seismic Array system to perform the following functions: (i) preprocess arriving seismic signals to increase their detectability, (ii) use such preprocessed signals to perform on-line automatic detection and location, (iii) process recordings of LASA data off-line, and (iv)(More)
Dynamic mechanical activity in a tunnel can be measured as ground vibrations at offset distances. These signals can be processed in sensing algorithms for detection, location, and discrimination of the activity. The objective of this work is to demonstrate that seismic simulations can reveal the effect of the environment on seismic energy as it propagates(More)
The results of a series of off-line signal processing experiments are presented for the experimental Large Aperture Seismic Array (LASA) located in eastern Montana. In particular, the signal-to-noise ratio gains achievable by maximum-likelihood processing, as well as other simpler forms of processing, are given as a function of frequency, aperture, and(More)
The signal-to-noise ratio improvement obtained with delay-and-sum (DS) processing is discussed fov short-period seismic data. It is shown that at least 3 km spacing should be maintained between seismometers at the Large Aperture Seismic Array (LASA) or at another site with a similar noise environment. It is shown that noise coherency measurements are of use(More)