Active Geophysical Monitoring

CHAPTER 12

STACKING STRATEGY FOR ACQUISITION OF AN ACROSS TRANSFER FUNCTION

Hiromichi Nagao^a,b, Takahiro Nakajima^a,Mineo Kumazawa^a, and Takahiro Kunitomo^a

Contents

1. Introduction

2. Methodology

2.1. Properties of signals and noise in ACROSS data

2.2. Derivation of optimum weight

2.3. Successive stacking for larger SNR

3. Application of optimum weighted stacking method

4. Conclusions

Acknowledgments

References

1. INTRODUCTION

A stacking technique is important for active monitoring in order to enhance the signal-to-noise ratio (SNR) of observed data. However, the expected SNR cannot be obtained when a simple stacking method, which averages whole data, is applied to a noisy data set. Typical sources of such contamination are local earthquakes in ...