8. Trace plotting, phase picking and spectral analysis, MULPLT

This program is the general plotting and signal analysis program. The program is capable of doing general phase picking, correct for instrument response, and produce Wood-Anderson seismograms for determining Ml, synthetic traces for Mb and Ms, determine azimuth of arrival for 3 component stations, do spectral analysis and particle motion. The program can also read in theoretical arrival times for global phases for help in identifying phases. If a quick location is needed based on a waveform file only, mulplt can both pick the phases and locate the event. MULPLT operates either as a database independent program (started with command MULPLT) or in connection with the database (started from EEV with command P or PO). If the program works independently of EEV, it will create an output file mulplt.out in Nordic format with the readings and results of spectral analysis. This file can directly be used with e.g. HYP. MULPLT reads and plots one channel at a time. This can be very time consuming when replotting traces and from SEISAN version 8.2, a certain number traces are kept in a memory buffer in order to speed up replotting and reprocessing The data is stored in one large array the size of which is determined at the time of compilation so for systems with many or long traces, it might have to be larger and for systems with little memory it might have to be smaller. The dimension is set in file seidim.inc in directory ./INC using variable max_mem_sample. A typical value is 30 000 000.

Note on Seed/Miniseed reading

The routines will put in zeros for gaps

If an overlap occurs, the block with the overlap will be discarded and zeros inserted.

If a block is out of time sequence, the block will be discarded, this is like a large negative overlap.

The channel start time will be considered the time of the first block found for that channel. If a block then occurs before the start time the block will be discarded.

Starting MULPLT from prompt line

Giving the command mulplt -h, will show the basic options:

  The MULPLT program - for plotting earthquake data 
  
  Usage: mulplt [options]
         enter input
  
  ## Options ##
    -help        Print this list
    -h           Same as -help
    -plotdefault Will plot data directly with default values  
    -qdp         Same as -plotdefault
    -po          Same as -plotdefault
    -version     SEISAN version 
  
  Examples:
        1)  mulplt
            enter values
        2)  mulplt -plotdefault -sfile /home/seismo/REA/TEST_/1996/06/03-1955-40D.S199606

Giving command mulplt, the question is

  Filename, number, filenr.lis (all)
  Continuous SEISAN data base: cont
  Large SEED volume: conts
  Archive: arc
  Make a choice

Filename, number, filenr.lis(all): The program asks for a file name or file number of a waveform file. To use the number, it is assumed that a list of files has first been created and numbered in a file filenr.lis using command DIRF, see section 15. By giving the number, the file corresponding to the selected number is used. By giving a ?, the list with numbers is displayed and a new number can be given. If many files are to be plotted with one command (hard copy only), give filenr.lis for file name and all events in FILENR.LIS will be plotted. There will only be one question about filter and then all events are plotted with all channels and the chosen filter.

Cont: Plot from a continuous data base. The program will use all data bases defined in SEISAN.DEF. A question will be given for absolute start time and window length. See also 8.5. Conts: Plot from a large SEED volume. A SEED file too large to be read in can be plotted in parts. A question will be given for file name or number. The file is then read and available data is displayed. Start time and window length is then entered.
arc: Plot from a BUD or SeisComp archive
Plot from a continuous archive. The program will use all channels defined in SEISAN.DEF. A question will be given for absolute start time and window length. See also 8.5. Then follows a display showing all stations and virtual networks that are defined in SEISAN.DEF before a channel selection is made. It is possible to combine selection of stations with one or more virtual networks. MULPLT removes duplicates in case a station should be selected more than once. See also secion 'Working with many channels in MULPLT' a bit later.

Subsections