Detection and Location of the Dead Sea Shots Using Advanced Processing Techniques
Abstract
Seismic data of the Dead Sea calibration experiment, which provided Ground Truth source parameters, were used in studying advanced signal processing methods. The data set includes recordings of the SP stations of the Israel Seismic Network (ISN), the EILAT Experimental Seismic Array (EILESA) and the IMS primary station GERESS. There were no detection problems at ISN and Cypriot stations (r<500 km), equipped by the simplest STA/LTA algorithm. Meanwhile, low SNR at the GERESS (R=2400 km) did not allow to detect even the largest explosion by the routine automatic procedure. We applied Adaptive Optimal Group Filter (AOGF) (Kushnir, 1995) method to the GERESS recordings, containing the explosion signal. The algorithm is based on computation of the preceding noise spectral matrix and theoretically provides undisturbed output signal with maximum SNR. The tool facilitated event detection, and yielded accurate estimations of the apparent velocity (plus or minus 1 km/sec) and back azimuth (plus or minus 20). Equivalent results were obtained by the Maximum Likelihood Technique (MLT) (Bohme, 1995) - the highly sensitive moving window spectral analyzer of array data, destined mainly for the detection of multiple signals. The same techniques were applied to the recordings of the EILESA - 8 station short period micro-array temporally deployed in the vicinity of the IMS BB station EIL. The algorithms provided satisfactory azimuth and velocity determination in spite of the poor array configuration. However, the estimates exhibited significant temporal variations of azimuth and apparent velocity attributed to heterogeneity of the upper crust.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2000
- Accession Number
- ADA529910
Entities
People
- Alona Malitzky
- Avi Shapira
- Vladimir Pinsky
- Yefim Gitterman