In this paper we analyze the signals from passive infrared (PIR) and seismic sensors to detect people. The PIR data analysis is done to determine the radiation source such as a human or an animal based on the signal strength, slopes of the signals, the number of Fresnel lens zones crossed by the target. The seismic data analysis is done to ascertain whether the footsteps belong to a human or an...

Near-source observations of five M 3.8-5.2 earthquakes near Ridgecrest, California are consistent with the presence of a seismic nucleation phase. These earthquakes start abruptly, but then slow or stop before rapidly growing again toward their maximum rate of moment release. Deconvolution of instrument and path effects by empirical Green's functions demonstrates that the initial complexity at ...

S U M M A R Y Converted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical s...

Fundamental to the ability to monitor a Comprehensive Nuclear-Test-Ban Treaty is a good understanding of the nuclear explosion source. Considerable research has been done on the nuclear explosion source over the past 30 years, with mixed success. Although empirical and numerical models of explosion sources do a fairly good job of matching observed seismic signals, a good explanation of the phys...

[1] Noise with periods 3 to 10 s, ubiquitous in seismic records, is expected to be mostly generated by pairs of ocean wave trains of opposing propagation directions with half the seismic frequency. Here we present the first comprehensive numerical model of microseismic generation by random ocean waves, including ocean wave reflections. Synthetic and observed seismic spectra are well correlated ...

Computerized seismic prospecting is an echo-ranging technique usually targeted at accurate mapping of oil and gas reservoirs. In seismic surveys an impulsive source, often an explosive charge, located at the earth's surface generates elastic waves which propagate in the subsurface; these waves are scattered by the earth's geological discontinuities back to the surface, where an array of receive...

The practical limits on resolution of images from seismic or radar (electromagnetic) data depend on the spectrum of the source pulse, the incompleteness of the recording geometry, and the fidelity with which one can model the reference medium. These factors together prevent one from recovering a point image from data produced by a point diffractor in a given body. A simple imaging formula quant...

We examine the conventional methodology for tying wells to processed seismic data and show why this methodology fails to allow for reliable interpretation of the seismic data for stratigraphy. We demonstrate an alternative methodology that makes the tie without the use of synthetic seismograms, but at the price of measuring the seismic source signature, the cost of such measurements being about...

This study developed a national seismic hazard map around Taiwan through a deterministic manner. The essential of this approach is to treat every historic event as a potential point source, then with the seismic hazard taken as the maximum ground motion resulted from the series of earthquake events. A program developed in-house was used to carry out mass computation and map-making. The results ...

A Bayesian statistics approach is applied in the seismogenic sources of Greece and the surrounding area in order to assess seismic hazard, assuming that the earthquake occurrence follows the Poisson process. The Bayesian approach applied supplies the probability that a certain cut-off magnitude of Ms = 6.0 will be exceeded in time intervals of 10, 20 and 75 years. We also produced graphs which ...