Last updated on August 12th 2016.
Note
The following links shows the example project as it should be just before step 4. You can use this to check your progress or restart the tutorial at this very point.
5. Waveform Data¶
Every inversion needs real data to be able to quantify misfit. The waveform
data for all events are stored in the DATA subfolder. The data for each
single event will be stored in a subfolder of the DATA folder with the
same name as the QuakeML file minus the .xml.
These folders are automatically created and updated each time a LASIF command is executed. If you followed the tutorial, your directory structure should resemble the following:
Tutorial
├── ADJOINT_SOURCES_AND_WINDOWS
│ ├── ADJOINT_SOURCES
│ └── WINDOWS
├── CACHE
│ ├── config.xml_cache.pickle
│ ├── event_cache.sqlite
│ └── statistics
├── DATA
│ ├── GCMT_event_NORTHERN_ITALY_Mag_4.9_2000-8-21-17
│ └── GCMT_event_NORTHWESTERN_BALKAN_REGION_Mag_5.9_1980-5-18-20
├── EVENTS
│ ├── GCMT_event_NORTHERN_ITALY_Mag_4.9_2000-8-21-17.xml
│ └── GCMT_event_NORTHWESTERN_BALKAN_REGION_Mag_5.9_1980-5-18-20.xml
├── FUNCTIONS
│ ├── __init__.py
│ ├── preprocessing_function.py
│ ├── process_synthetics.py
│ ├── source_time_function.py
│ └── window_picking_function.py
├── ITERATIONS
├── KERNELS
├── LOGS
├── MODELS
├── OUTPUT
├── STATIONS
│ ├── RESP
│ ├── SEED
│ └── StationXML
├── SYNTHETICS
│ ├── GCMT_event_NORTHERN_ITALY_Mag_4.9_2000-8-21-17
│ └── GCMT_event_NORTHWESTERN_BALKAN_REGION_Mag_5.9_1980-5-18-20
├── WAVEFIELDS
└── config.xml
All data in the DATA subfolder has to be processed or unprocessed actual
data. The data is further structured by assigning a tag to every data set. A
tag is assigned by simply placing a folder in ROOT/DATA/EVENT_NAME and
putting all data in there. The special tag raw is reserved for the raw
waveforms straight from the datacenters or some other source. Other tags should
describe the filtering and processing applied to the data (LASIF’s built-in
processing capabilities actually enforce certain tag names - this will be
covered in more detail later on). The same is true for synthetic waveform data,
except that in that case, the data resides in the SYNTHETICS folder and
the tags have to coincide with the iteration names. More on this later on.
After a while, the structure might look like this:
Tutorial
|-- DATA
│ ├── GCMT_event_NORTHERN_ITALY_Mag_4.9_2000-8-21-17-14
|-- raw
|-- preprocessed_hp_0.01000_lp_0.12500_npts_4000_dt_0.130000
|...
|-- SYNTHETICS
│ ├── GCMT_event_NORTHERN_ITALY_Mag_4.9_2000-8-21-17-14
|-- ITERATION_1
|-- ITERATION_2
|...
|...
|...
The user is responsible for adhering to this structure. Otherwise other parts of LASIF cannot operate properly. Many commands shipping with LASIF ease that process.
LASIF is able to deal with waveform data in essentially every common format thanks to being built on top of ObsPy. We recommend to use the MiniSEED format as this is the format that is shipped by effectively all data centers.