Active Geophysical Monitoring

CHAPTER 4

SEISMIC ACTIVE MONITORING SYSTEM CONCEPT

Rudolf Unger^a,b

Contents

1. Introduction

2. System Concept

3. Force Signal Signatures

3.1. Pseudo-random sequence signal

3.2. Pseudo-random sequence modulation

4. Quadrature Signal Processing

4.1. Parameter definition

4.2. Waveform modulation/demodulation

4.3. Matched filtering

4.4. Signal detection and timing algorithm

5. Conclusions

References

1. INTRODUCTION

Various attempts have been made to measure parametric changes in the Lithosphere, in particular for the purpose of finding potential earthquake precursors. Passive monitoring is performed by means of time-lapse seismic tomography or wave propagation velocity measurement using regional or teleseismic earthquakes as wave propagation sources. ...