event.conf¶

Secondly, event dependent options can be changed in the config file (eventname.config) of the event in the eventfolder, which will be created after step 2. Please make sure to investigate this configuration file closely before further processing.

And lastly, synthetic sources can be specified in the syn config file (eventname.syn) in the eventfolder, also created after step 2. A user definded number of RectangularSources or DoubleCouble sources can used to create synthetic data with free user input of the source parameters. See the pyrocko documentation for details about the sources. This configuration file also contains paths to greensfunction stores.

The main event configuration file is created when the palantiri_create command is called.

The main event configuration file is separated in several sub sections.

Clusterparameter¶

The first subsection, [clusterparameter], defines the parameters describing the cluster algorithm:

[clusterparameter]

The following parameter described the maximum number of desired array clusters that should be optimized for.
Note that the actual number will vary from this.
maxCluster = 100

The number of the minimum number of stations in initial clusters (should be higher than the desired minimum number of stations per array)
minStationAroundInitialCluster = 10

The distance which is used initially to gather stations in an array. The final minimum array aperture will not depend on this. It should be  approximately 2x times the desired minimum array aperture.
initialstationdistance = 7

Cutoff is a hard break option in number of iterations for the clustering algorithm.
cutoff = 100
runs defines the number of times the clustering algorithm is applied.
The final cluster setup to be used will be the one that performs best in terms of maximized number of stations and clusters used from all runs.
runs = 1

This defines the minimum distance of initial seach centroids [in degree]. Larger numbers means that less search centroids are spawned. This results in more distance between arrays.
centroidminDistance = 2

The maximum distance from station to cluster center (maximum array aperture)
stationdistance = 5
The minimum number of stations per cluster
minClusterStation = 5

traveltime calculation options¶

The next chapter in the configuration file is for traveltime definitions and traveltime grid calculations:

[traveltime calculation options]

traveltime_model = ak135-f-continental.m.nd
#number of cores for traveltime calculation
ncore = 2

#depths= Repeat semblance calculation from,to,steps relative to depth in origin config
depths=0,0,5
# run each depth step with a number of filter(s), used for high vs. low freq.
filters=2

# dimx of grid
dimx = 20
# dimy of grid
dimy = 20

True or false. The traveltimes and the semblance will be calculated in a cube. The parameter for the minimum and maximum depth and step size are given in the depths parameter.
dimz= 0

# gridspacing in degree
gridspacing = 0.035
# Phase to consider [right now only P possible!]
ttphases=P

futterman_attenuation = 0

Traveltime corrections¶

traveltime correction options:

[Traveltime corrections]

Whether to apply shifts or not. Can be independent from the run to calculate the shifts.
correct_shifts = 0

Set true if you wish to calculate the empirical shifts or if you want to load in already calculated shifts.
correct_shifts_empirical_run = 0

Use empirical shift from fore or aftershock or calculate shifts based on maximizing the correlation [default].
correct_shifts_empirical = 0

Load in a manual file
correct_shifts_empirical_manual = 0

Calculate the empirical shifts per array (faster, default) or for each station individually.
correct_shifts_empirical_manual_station_wise = 0

Use synthetic or real event [default]:
correct_shifts_empirical_synthetic=0

# dimx of grid for empirical correction (should be the same as for the main process in most cases)
dimx_emp = 1
# dimy of grid (should be the same as for the main process in most cases)
dimy_emp = 1
# step length in s.
step_emp = 16
# window length in s.
winlen_emp = 16
the duration of the waveform in [s] after the theoretical onset of the specified phase
duration_emp = 8
the duration of the waveform in [s] before the theoretical onset of the specified phase
forerun_emp = 8

Beamforming method¶

Several methods for the backprojection are possible: 1. traditional (capon) beamforming 2. coherence based stacking (bp_coh), 3. phase weighted stacking (pws), 4. stacking in the frequency domain (bp_freq), 5. music (bp_music). Compressed sensing is only partly supported right now.

Select the method for Backprojection in the following section:

[beamforming method]

#delaysum
#capon
beam = delaysum

bp_freq= 0
bp_coh= 0
bp_music = 0

# use a phase weighted stacking
shift_by_phase_pws = 0

# create output of compressed sensing as grid [warning: experimental]
cs = 0

Algorithm settings¶

Define general settings:

[algorithm settings]

weight_by_noise = 0
weight_by_azimuth = 0
# bootstrap the arrays to estimate the uncertainty:
bootstrap_array_weights = 0
# number of bootstraps to carry out:
n_bootstrap = 0

Use arrays separately [default] or all in one big step:
combine_all = 0
Normalize the semblance of each array to 1.
norm_all=1

General settings¶