77 lines
6.4 KiB
Markdown
77 lines
6.4 KiB
Markdown
|
# Pick-Correlation Correction
|
|||
|
|
|
|||
|
|
## Introduction
|
|||
|
|
Currently, the pick-correlation correction algorithm is not accessible from they PyLoT GUI. The main file *pick_correlation_correction.py* is located in the directory *pylot\correlation*.
|
|||
|
|
The program only works for an obspy dmt database structure.
|
|||
|
|
|
|||
|
|
The basic workflow of the algorithm is shown in the following diagram. The first step **(1)** is the normal (automatic) picking procedure in PyLoT. Everything from step **(2)** to **(5)** is part of the correlation correction algorithm.
|
|||
|
|
|
|||
|
|
*Note: The first step is not required in case theoretical onsets are used instead of external picks when the parameter use_taupy_onsets is set to True. However, an existing event quakeML (.xml) file generated by PyLoT might be required for each event in case not external picks are used.*
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
A detailed description of the algorithm can be found in the corresponding publication:
|
|||
|
|
|
|||
|
|
*Paffrath, M., Friederich, W., and the AlpArray and AlpArray-SWATH D Working Groups: Teleseismic P waves at the AlpArray seismic network: wave fronts, absolute travel times and travel-time residuals, Solid Earth, 12, 1635–1660, https://doi.org/10.5194/se-12-1635-2021, 2021.*
|
|||
|
|
|
|||
|
|
## How to use
|
|||
|
|
To use the program you have to call the main program providing two mandatory arguments: a path to the obspy dmt database folder *dmt_database_path* and the path to the PyLoT infile *pylot.in* for picking of the beam trace:
|
|||
|
|
|
|||
|
|
```python pick_correlation_correction.py dmt_database_path pylot.in```
|
|||
|
|
|
|||
|
|
By default, the parameter file *parameters.yaml* is used. You can use the command line option *--params* to specify a different parameter file and other optional arguments such as *-pd* for plotting detailed information or *-n 4* to use 4 cores for parallel processing:
|
|||
|
|
|
|||
|
|
```python pick_correlation_correction.py dmt_database_path pylot.in --params parameters_adriaarray.yaml -pd -n 4```
|
|||
|
|
|
|||
|
|
## Cross-Correlation Parameters
|
|||
|
|
|
|||
|
|
The program uses the parameters in the file *parameters.yaml* by default. You can use the command line option *--params* to specify a different parameter file. An example of the parameter file is provided in the *correlation\parameters.yaml* file.
|
|||
|
|
|
|||
|
|
In the top level of the parameter file the logging level *logging* can be set, as well as a list of pick phases *pick_phases* (e.g. ['P', 'S']).
|
|||
|
|
|
|||
|
|
For each pick phase the different parameters can be set in the first sub-level of the parameter file, e.g.:
|
|||
|
|
|
|||
|
|
```yaml
|
|||
|
|
logging: info
|
|||
|
|
pick_phases: ['P', 'S']
|
|||
|
|
|
|||
|
|
P:
|
|||
|
|
min_corr_stacking: 0.8
|
|||
|
|
min_corr_export: 0.6
|
|||
|
|
[...]
|
|||
|
|
|
|||
|
|
S:
|
|||
|
|
min_corr_stacking: 0.7
|
|||
|
|
[...]
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
The following parameters are available:
|
|||
|
|
|
|||
|
|
|
|||
|
|
| Parameter Name | Description | Parameter Type |
|
|||
|
|
|--------------------------------|----------------------------------------------------------------------------------------------------|----------------|
|
|||
|
|
| min_corr_stacking | Minimum correlation coefficient for building beam trace | float |
|
|||
|
|
| min_corr_export | Minimum correlation coefficient for pick export | float |
|
|||
|
|
| min_stack | Minimum number of stations for building beam trace | int |
|
|||
|
|
| t_before | Correlation window before reference pick | float |
|
|||
|
|
| t_after | Correlation window after reference pick | float |
|
|||
|
|
| cc_maxlag | Maximum shift for initial correlation | float |
|
|||
|
|
| cc_maxlag2 | Maximum shift for second (final) correlation (also for calculating pick uncertainty) | float |
|
|||
|
|
| initial_pick_outlier_threshold | Threshold for excluding large outliers of initial (AIC) picks | float |
|
|||
|
|
| export_threshold | Automatically exclude all onsets which deviate more than this threshold from corrected taup onsets | float |
|
|||
|
|
| min_picks_export | Minimum number of correlated picks for export | int |
|
|||
|
|
| min_picks_autopylot | Minimum number of reference auto picks to continue with event | int |
|
|||
|
|
| check_RMS | Do RMS check to search for restitution errors (very experimental) | bool |
|
|||
|
|
| use_taupy_onsets | Use taupy onsets as reference picks instead of external picks | bool |
|
|||
|
|
| station_list | Use the following stations as reference for stacking | list[str] |
|
|||
|
|
| use_stacked_trace | Use existing stacked trace if found (spare re-computation) | bool |
|
|||
|
|
| data_dir | obspyDMT data subdirectory (e.g. 'raw', 'processed') | str |
|
|||
|
|
| pickfile_extension | Use quakeML files (PyLoT output) with the following extension | str |
|
|||
|
|
| dt_stacking | Time difference for stacking window (in seconds) | list[float] |
|
|||
|
|
| filter_options | Filter for first correlation (rough) | dict |
|
|||
|
|
| filter_options_final | Filter for second correlation (fine) | dict |
|
|||
|
|
| filter_type | Filter type (e.g. bandpass) | str |
|
|||
|
|
| sampfreq | Sampling frequency (in Hz) | float |
|
|||
|
|
|
|||
|
|
## Example Dataset
|
|||
|
|
An example dataset with waveform data, metadata and automatic picks in the obspy-dmt dataset format for testing can be found at https://zenodo.org/doi/10.5281/zenodo.13759803
|