In SEISAN one can plot or extract continous data from either a standard SEISAN database (internally many different formats) or from a BUD or a SeiscomP archive (internal format MiniSeed. The archive option is the most common way to use continous data in SEISAN. It is easy to convert most format to MiniSeed with WAVETOOL and the use any group of MiniSeed files to create the archive with program DATASELECT (included in SUP), see section 'getting data into the data base' See also page .
Continous data in a BUD or SeiscomP archive
SEISAN reading BUD and SeisComp archives
SEISAN is able to read miniseed from a BUD and SeisComp (SDS) archives data structure.
The reading routines using Chad Trabant software have been implemented by Ruben Luis.
Reading continuous data:
This works just like reading SEISAN continuous data, except there are no S-files, only the archive files. All the same functions are available:
Plotting, zooming and extracting segments and registering events.
Read archive data as an event from eev:
A reference to a segment is made in the s-file and it is treated as if it was a file. When a keyword for archive (ARC) is found, the reading is directed to the archive instead of to a file. The archive reference is e.g.
ARC STAT COM NT LO YYYY MMDD HHMM SS DUR ARC ROSA BHZ PM 2010 1011 0100 00 14400 6where ARC indicate archive, STAT is station code, COM is component, LO is location code YYYY MMDD HHMM SS is start time and DUR is duration in secs.
ARC STAT COM NT LO YYYY MMDD HHMM SS DUR ARC P 2010 1011 0100 00 14400 6
Station begins with _ indicates virtual network as defined in SEISAN.DEF. This can also be inserted with arc command in EEV. Example of link to virtual network named _CTBTO in sfile, below format line:
ARC STAT COM NT LO YYYY MMDD HHMM SS DUR ARC _CTBTO 2010 1011 0100 00 14400 6
Plotting all stations without an archive reference line:
If parameter ARC_BY_DEFAULT in SEISAN.DEF is set to 1, all
channels in the archive will be selected.
NOTE: An ARC line can be inserted/edited in the S-file from EEV by command arc.
The archive is defined in SEISAN.DEF where each channel is defined by ether an ARC_CHAN2 line (from version 12) or an ARC_CHAN line (still possible, this was the only option prior to version 12). ARC_CHAN2 makes it easier to define virtual networks, which with ARC_CHAN have to be defined through ARC_VIRTUAL_NETWORK lines. Another improvement is that with ARC_CHAN2 it is possible to specify the archive with variables that are defined through ARC_ARCHIVE2 lines.
Here is an example of using the ARC_CHAN2 definition and definition of the nnsn_eida archive variable:
ARC_ARCHIVE2 nnsn_eida /home/seismo/WAV/SLARCHIVE ------------------------------------------------------------------------------------------------------------------------ --------- explanation arc_chan2 S C N L Def Start Stop Archive Vnet1 Vnet2 Vnet3 Vnet4 Vnet5 Vnet6 ------------------------------------------------------------------------------------------------------------------------ ARC_CHAN2 ASK HHZNS00 1.0 20181106 nnsn_eida _SW _SN _NNSN ARC_CHAN2 ASK HHNNS00 1.0 20181106 nnsn_eida _SW _SN _NNSN ARC_CHAN2 ASK HHENS00 1.0 20181106 nnsn_eida _SW _SN _NNSN ARC_CHAN2 ASK EHZNS00 1.0 20181106 nnsn_eida _SW _SN _NNSN ARC_CHAN2 ASK EHNNS00 1.0 20181106 nnsn_eida _SW _SN _NNSN ARC_CHAN2 ASK EHENS00 1.0 20181106 nnsn_eida _SW _SN _NNSN
The columns in the ARC_CHAN2 line contain:
41-52: station, component, network and location
54-56: start date as yyyymmdd
58-65: stop date as yyyymmdd
67-74: archive name that is pointing to archive path
76-84: name of virtual network that station is part of
86-90:name of virtual network that station is part of
92-96:name of virtual network that station is part of
98-102: name of virtual network that station is part of
104-108: name of virtual network that station is part of
110-114: name of virtual network that station is part of
116-120: name of virtual network that station is part of
The ARC_ARCHIVE2 line gives the archive name (41-49) and the respective archive path (51-). One can add several ARC_ARCHIVE2 lines.
When defining a channel using a
text string: SSSSSCCCNNLL, where SSSSS is the station,
CCC is the component, NN the network and LL the location.
These lines can be generated with program sample_read_wav, which will
make a list of all channels in a given set of files (it thus requires to have
one of several single files with the channels needed).. An alterentive is to use program GET_ARC_CHANNELS which will
scan an archvie to list the channels in SEISAN.DEF format.
See section 'Waveform file management tools'.
The directory of the archive is given by
ARC_ARCHIVE, see e.g.:
ARC_CHAN PMOZ BHZPM ARC_CHAN PMOZ BHNPM ARC_CHAN PMOZ BHEPM ARC_CHAN SFJD LHZIU10 ARC_CHAN SFJD LHNIU10 ARC_CHAN SFJD LHEIU10 ARC_ARCHIVE /uibsan/home/s2000/BUDARC ARC_DURATION 10000.0 ARC_START_TIME 5000.0 ARC_TYPE 1.0 ARC_BY_DEFAULT 0.0where each channel is defined as well as the location of the archive. The specification is the same for both BUD and SeisComp archives. ONLY one archive type can be used at the same time and the archive type, ARC_TYPE is given in SEISAN.DEF.
ARC_VIRTUAL_NETWORK _NO BER HHZNS00 ARC_VIRTUAL_NETWORK _NO BER HHNNS00 ARC_VIRTUAL_NETWORK _NO BER HHENS00The virtual network name has to start with a '_' to make them visible as such in the station selection.
Continous data in a SEISAN database
In SEISAN continuous data has no special format. Continuous data is simply ordinary waveform files that follow each other in time. In order to treat the data as continuous, the data can be put into a SEISAN continuous data base. Such a data base is made as follows:
|-||For each waveform file from a station or network, an S-file is created. The S-files only contain reference to the waveform file(s). Program AUTOREG can be used to create the S-files.|
|-||The waveform data is optionally put into the corresponding waveform station directories, however they can also be in WAV or working directory. For large data sets it is strongly recommended to use the WAV database structure.|
|-||The continuous databases are defined in SEISAN.DEF in DAT.|
If e.g. data is to be stored from 3 different stations (three componet files), create 3 databases under WAV and REA with the name of the stations (program MAKEREA). If the continuous data consist of 20-minute files, this would mean about 2200 files pr month, which is a reasonable number. It is now possible for some programs (MULPLT, WAVETOOL) to get access to any or all of the traces in the continuous data base and plot and extract data. If the continuous data is archived from a real-time system it is best to have one database per station as it will at times be necessary to backfill gaps as data may not have arrived in real-time.
Note that waveform files in a SEISAN continuous structure must contain the year and month which is used to located the corresponding year-month structure. The default start of the file names accepted are:
ccmm ccyy-mm ccyymm
where cc is century, yy is year and mm is month. If year and month are placed diffenrently in the file name, their location must tbe specified in SEISAN.DEF, parmeter CONT_YEAR_MONTH_POSTION_FILE.
It is also possible to store the data without having a database for each station:
The waveform files in a continuous data base can have different formats for different stations and one S-file can refer to more than one waveform file, provided they start at about the same time and have the same duration.
A simpler way to use smaller quantities of continuous data is to make a list of these files with DIRF and an application program can then use that list to work with the data. Currently two programs have special options for this kind of continuous data. The MULPLT program will plot data from several files as if it was one file in one continues trace the RESAMP program will resample the data from several files and put it into one output file.
Peter Voss 2022-08-29T10:10Z | Please contact firstname.lastname@example.org regarding the webpage, it is hosted by The Geological Survey of Denmark and Greenland (GEUS) | xxxxxxxxxxxyyyyyyyyyyyy