A Discrimination Study of Seismic Tunnel Echoes.
Abstract
The purpose of this project was the investigation of several methods of signal processing intended to enhance tunnel echo indications from surface-operated seismic sounding devices. Magnetic tape recordings of pulse-echo soundings over several tunnels in the Washington, D. C. area were collected. An electrodynamic shaker was used as the acoustic source, and moving-coil geophones were used as sensors in the sounding array. Signal processing techniques included spectral analysis, cepstrum and correlation analysis, and frequency filtering. The results of the analysis of data collected over three tunnels were not as definitive as originally expected. Crosscorrelation of sensor outputs appeared to enhance echo indication in the case of one tunnel. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1968
- Accession Number
- AD0845569
Entities
People
- Peter Sypher
Organizations
- Melpar