/ruido

A set of scripts to run measurements of fractional velocity change dv/v on cross-correlations of ambient seismic noise.

Primary LanguagePython

Ruido - a set of scripts to handle highly time-resolved ambient noise correlation data

The purpose of these objects and scripts is to bring us from (short-term unstacked) ambient noise correlation data to .csv files with dv/v measurements.

When we compute hourly or sub-hourly correlations from continuous ambient noise data, we end up with tens of thousands of individual windows. This module is designed to work on such data organized in hdf5 files with the format that is shown below ("hdf5 file format"). Correlations in this format are written out directly by the ants module (https://github.com/lermert/ants_2).

Idea

The scripts directory contains three scripts. One is for clustering following Viens & Iwata (2020)(https://github.com/lviens/2020_Clustering), one for stacking, and one for taking dv/v measurements.

To use the scripts, take these steps:

  1. Edit the config.yml file. Set do_clustering, do_stacking and do_measurement to true or false. Then, edit all the rest. Do not remove any parameters, just ignore the irrelevant ones (e.g. when do_clustering is false, all parameters relevant to clustering will simply be ignored.). Note that you can run the steps separately, e.g. for doing quality control in between, simply by first setting only do_clustering to true, then setting only do_stacking to true and so on.
  2. Call python <path-to-ruido-main>/ruido_main.py <configfile-name>. For parallel run, call mpirun -np <nr-processes> <path-to-ruido-main>/ruido_main.py <configfile-name>

You can also interactively use the objects in classes/ to load, filter, stack correlation data. For example:

from ruido.classes.cc_dataset_serial import CCDataset_serial
d = CCDataset_serial("filename.h5")
d.data_to_memory(ix_corr_max=1000)
print(d)
d.dataset[0].filter_data(0.1, "bandpass", 2.0, 4.0)
d.plot_stacks(stacklevel=0)  # stacklevel=0: We have not stacked anything yet. This will plot the raw correlation waveforms in d.dataset[0]

Underlying idea

The central bookkeeping device is the CCDataSet object which itself is a dictionary of CCData objects. The most important tasks these two fulfill is reading the data from hdf5 (either partially or full), tapering / filtering them, plotting them, selecting them for stacking based on various criteria, and forming the stack, as well as taking stretching measurements with respect to a reference. There is a serial and a parallel version designed to handle the same tasks, but one in a serial context and one using mpi4py to split processing tasks among processes.

hdf5 file format for data (single floats could be used in place of doubles, too)

HDF5 "NET.STA.LOCATION.CHANNEL--NET.STA.LOCATION.CHANNEL.ccc.windows.h5" {
GROUP "/" {
GROUP "corr_windows" {
DATASET "data" {
DATATYPE H5T_IEEE_F64LE
DATASPACE SIMPLE { ( NR OF TRACES, NR OF SAMPLES ) / ( NR OF TRACES, NR OF SAMPLES ) }
}
DATASET "timestamps" {
DATATYPE H5T_STRING {
STRSIZE H5T_VARIABLE;
STRPAD H5T_STR_NULLTERM;
CSET H5T_CSET_UTF8;
CTYPE H5T_C_S1;
}
DATASPACE SIMPLE { ( NR OF TRACES ) / ( NR OF TRACES ) }
}
}
DATASET "stats" {
DATATYPE H5T_STD_I64LE
DATASPACE SIMPLE { ( 1 ) / ( 1 ) }
ATTRIBUTE "channel1" {
DATATYPE H5T_STRING {
STRSIZE H5T_VARIABLE;
STRPAD H5T_STR_NULLTERM;
CSET H5T_CSET_UTF8;
CTYPE H5T_C_S1;
}
DATASPACE SCALAR
}
ATTRIBUTE "channel2" {
DATATYPE H5T_STRING {
STRSIZE H5T_VARIABLE;
STRPAD H5T_STR_NULLTERM;
CSET H5T_CSET_UTF8;
CTYPE H5T_C_S1;
}
DATASPACE SCALAR
}
ATTRIBUTE "distance" {
DATATYPE H5T_IEEE_F64LE
DATASPACE SCALAR
}
ATTRIBUTE "sampling_rate" {
DATATYPE H5T_IEEE_F64LE
DATASPACE SCALAR
}
}
}
}