1.
Outline
BIDO is an analysis tool we offer free for the array
exploration of microtremors. The software can be used to identify
properties of surface waves that travel on the ground surface by analyzing circular-array
records of microtremors.
Since 2000, our research group, centered on the
(former) Shinozaki laboratory at the Tokyo University of Science (joint
research by Professor Yuzo Shinozaki, Dr Taku Tada, myself [Ikuo Cho] and
graduate students) have undertaken generalization of the SPAC method theory ("generic formulation for circular-array
analysis", reference [2] ),
and have developed methods that allowed phase velocities of Rayleigh waves to
be identified into much longer wavelength ranges than the traditional SPAC
method (the CCA method and other derivative methods, reference [1, 3, 4, 5]). Our theories have
also made it possible to identify phase
velocities of Love waves (reference [5]),
signal-to-noise ratios (reference [3, 8]), horizontal-to-vertical amplitude ratios (R/V spectra) of Rayleigh waves (reference [2]), and Rayleigh-to-Love power ratios (reference [5, 7]) with simple methods
unknown in traditional approaches. BIDO is an analysis tool for microtremor data (circular-array records) that uses these
methods to identify properties of surface waves.