Last updated on August 12th 2016.
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.
6. Download Helpers¶
This part is not actually necessary for the tutorial but most likely for any real work application.
LASIF comes with a collection of scripts that help downloading waveform and station data from all data centers implementing the FDSN web services. This largely amounts to data from Europe, Northern America, Brazil, and New Zealand. If your inversion requires data from other places, you’ll have to retrieve it on your own.
6.1. Downloading Data¶
Data are downloaded on a per event basis. The
config.xml file contains
some specification to detail the download.
To download the data for an event, choose one and run
$ lasif download_data GCMT_event_TURKEY_Mag_5.1_2010-3-24-14-11
The command just tries to download everything it can within your chosen domain,
both the waveforms and station metadata. It queries successively queries all
known FDSN data centers and integrates all data. It accounts for the domain
borders and possible domain rotations. It is furthermore influenced by the
following parameters in the
seconds_before_event: Used by the waveform download scripts. It will attempt to download this many seconds for every waveform before the origin of the associated event.
seconds_after_event: Used by the waveform download scripts. It will attempt to download this many seconds for every waveform after the origin of the associated event. Adapt this to the size of your inversion domain.
interstation_distance_in_m: The minimum distance between two stations so that data from both would be downloaded in meters. If stations are closer than that only one is downloaded.
channel_priorities: The priority in which channels will be chosen from each station.
location_priorities: The priority in which location codes will be chosen from each station.
Depending on the domain size, event location, and origin time, this can take a
while. Executing the same command again will only attempt to download data not
already present. All waveform data will be placed in
and all station data in
At this point it is worth mentioning that LASIF keeps logs of many
actions that the user performs. All logs will be saved in the