# Eqcoda Configuration File Commands

(last revised 21 August 2000)
Page Index:
1. Example configuration file
2. Functional command listing
3. Alphabetic command listing & description
4. Notes on eqcoda's default values for its constants

On startup, eqcoda reads the configuration file named on the command-line. Commands in this file set up all parameters used in extrapolating coda durations. In the control file, lines may begin with a valid eqcoda command (listed below) or with one of 2 special characters:

>     #  marks the line as a comment (example: # This is a comment).

>     @  allows control files to be nested; one control file can be
>        accessed from another with the command "@" followed by
>        a string representing the path name of the next control file
>        (example: @model.d).

Command names must be typed in the control file exactly as shown in this document (upper/lower case matters!).

## 1. EXAMPLE CONFIGURATION FILE

    #
    # This is eqcoda's parameter file
    #
    MyModuleId  MOD_EQPROC  # module id to label logfile  with.
                            # Note: eqcoda is part of a mega-module which is
                            # ultimately started by the program eqproc.  All
                            # child processes of this mega-module need to use the
                            # same module id (thus use eqproc's module id).

    LogFile       1         # 0=log to stderr/stdout only
                            # 1=log to disk and stderr/stdout
                            # 2=log to disk only

    LabelAsBinder 0         # 0=label phases as generic P and S;
                            # non-zero = label phases as binder did

    LabelVersion  0         # Optional command; default LabelVersion=1
                            # 0 = write a blank in the version field of the
                            #   summary line of the TYPE_HYP2000ARC msg
                            # non-zero = use the version number passed from
                            #   eqproc,eqprelim on the summary line.

    # PipeTo sends eqcoda's output to one of these three modules:
    #   eqverify        performs some tests to determine if the event
    #                   is noise or a real earthquake.
    #   hyp2000_mgr     locates event and calculates coda duration mag.
    #   log_everything  debug tool which writes all of eqcoda's
    #                   output to the screen and to a file
    #                   in the EW_PARAMS directory named "junkfile".
    #--------------------------------------------------------------
    # PipeTo "eqverify eqverify.d"
    PipeTo "hyp2000_mgr hyp2000_mgr.d ncal2000.hyp"
    # PipeTo "log_everything"

    # StaFile loads per-channel parameters (added in v5.1).
    # Use same station list as pick_ew.  eqcoda uses only the
    # SCN, CodaTerm and ClipCount fields and ignores the rest.
    #--------------------------------------------------------------
    StaFile   pick_ew.sta

    # Obsolete commands (in v5.1 and higher)
    #--------------------------------------------------------------
    # Define the coda termination level (counts) and clipping
    # levels for all channels.  Default values are appropriate for
    # Earthworm 12-bit data.
    # coda_term     49.14  	# same as CodaTerm in pick_ew stationfile
    # coda_clip       820
    # p_clip1         984
    # p_clip2        1148

## 2. FUNCTIONAL COMMAND LISTING

Below are the commands recognized by eqcoda, grouped by the function they influence. Some of the commands are marked "required"; they describe the Earthworm system setup. These commands must be specified in the control file in order for eqcoda to operate.

    	Earthworm system setup:
     		MyModuleId	required
                    PipeTo          required

            Constants:
    		coda_cutoff	obsolete
    		coda_clip	obsolete
    		p_clip1		obsolete
    		p_clip2		obsolete
     		pi.c7		obsolete
     		StaFile

    	Output Control:
    		LabelAsBinder   required
    		LabelVersion
    		LogFile		required

## 3. ALPHABETIC COMMAND LISTING & DESCRIPTION

In the following section, all configuration file commands are listed in alphabetical order. Listed along with the command (bold-type) are its arguments (in red), the name of the subroutine that processes the command, and the function within the module that the command influences. A detailed description of the command and is also given. Default values and the values used by Calnet are listed after each command description.

    command arg1				processed by		function

    coda_cutoff cutoff			eqc_config		constants

> Obsolete in v5.1 and higher
> Define default coda termination level (counts). The "coda_cutoff" and "pi.c7" commands are interchangeable. Coda duration is reported as the time from the P-arrival to the time when the average absolute amplitude of a 2-second trace data window reaches cutoff counts. Eqcoda extrapolates the coda decay to a level of cutoff counts, estimating the coda duration for those picks that pick_ew has timed-out on (pick_ew waits a maximum of 144 seconds for the coda to reach the cutoff value). For extrapolated coda lengths to be consistent with "normally-terminating" (<144 sec) coda lengths reported by pick_ew, be sure that both modules are configured with the same coda-termination value. Traditionally, codas have been "terminated" when the average absolute amplitude in a 2 second window reaches 60 mV.

>     Default:  coda_cutoff 49.15

    coda_clip klipc				eqc_config		constants

> Obsolete in v5.1 and higher
> Define the number of counts KlipC above which a 2-second trace data window's average absolute amplitude should be considered as clipped. Clipped values will not be used in coda fitting and extrapolation.

>     Default:  coda_clip 820			Calnet:  coda_clip 820

    LabelAsBinder switch			eqc_config		output

> Sets the switch for how phases are labeled in the archive message that will be sent to the next process. If switch is 0, phases are labeled as generic P or S. If switch is non-zero, each phase will be labeled with the phase descriptor attached to that pick by binder. The table below lists possible phase labels:

>        ------------------------------------------------------
>          LabelAsBinder        Station Archive Line
>             switch        cols. 5-6         cols. 37-38
>        ------------------------------------------------------
>               0           " P"              " S"
>            non-zero       "P ","Pn","Pg"    "S ","Sn","Sg"
>        ------------------------------------------------------

> Hypoinverse does not use the phase label; it just passes the label along into its output archive file.

>     Default:  none				Calnet:  LabelAsBinder 0

    LabelVersion switch			eqc_config		output

> Determines whether eqcoda will write a version number on the summary line of the TYPE_HYP2000ARC message that it outputs. If switch is 0, the version field will remain blank. If switch is non-zero, the version number passed from eqproc or eqprelim will be written into the hypoinverse version field.

>     Default:  LabelVersion 1

    LogFile switch				eqc_config		output

> Sets the on-off switch for writing a log file to disk and/or screen. If switch is 0, no log file will be written, but messages may go to stderr and/or stdout. If switch is 1, eqcoda will write daily log file(s) called eqcodaxx.log_ccyymmdd where xx is eqcoda's module id (set with "MyModuleId" command) and ccyymmdd is the current UTC date (ex: 19960123) on the system clock. The file(s) will be written in the EW_LOG directory (environment variable). Messages may also go to stderr and/or stdout. If switch is 2, the log file will be written, but no messages will go to stderr or stdout.

>     Default:  none

    MyModuleId mod_id			eqc_config		Earthworm setup

> Sets the module id for labeling all outgoing messages. mod_id is a character string (valid strings are listed in earthworm.d) that relates (in earthworm.d) to a unique single-byte number.
> NOTE: eqcoda is part of a mega-module which is ultimately started by the program eqproc. All sub-modules of this megamodule should be given the same module id.

>     Default:  none				Calnet:  MyModuleId MOD_EQPROC

    p_clip1 klipP1				eqc_config		constants

> Obsolete in v5.1 and higher
> Define the number of counts KlipP1 above which the first P-amplitude (of 3) reported by pick_ew should be considered to be clipped. Clipped values will not be used in calculating the average P-amplitude.

>     Default:  p_clip1 984			Calnet:  p_clip1 984

    p_clip2 klipP2				eqc_config		constants

> Obsolete in v5.1 and higher
> Define the number of counts KlipP2 above which the 2nd and 3rd P-amplitudes (of 3) reported by pick_ew should be considered to be clipped. Clipped values will not be used in calculating the average P-amplitude.

>     Default:  p_clip2 1148			Calnet:  p_clip2 1148

    pi.c7 cutoff				eqc_config		constants

> Obsolete in v5.1 and higher
> The "coda_cutoff" and "pi.c7" commands are interchangeable. See above description for the "coda_cutoff" command.

>     Default:  coda_cutoff 49.15		Calnet:  coda_cutoff 49.15

    PipeTo cmdstring			eqc_config		Earthworm setup

> Sets the command to which eqcoda will pipe its output for the next step in earthquake processing. Eqcoda produces a TYPE_HYP2000ARC message, in the format of a hypoinverse archive file (with shadow cards), for each event. One of these modules should be used to process eqcoda's output:

>       eqverify        performs some tests to determine if the event
>                       is noise or a real earthquake.

>       hyp2000_mgr     locates event and calculates coda duration mag
>                       using hypoinverse.

>       log_everything  debug tool which writes all of eqcoda's
>                       output to the screen and to a file in
>                       the EW_PARAMS directory named "junkfile".

> Blank spaces are allowed in cmdstring as long as the entire command is enclosed in double-quotes.

>     Default:  none
>     Calnet:   PipeTo "eqverify eqverify.d"

    StaFile stationfile			eqc_config		constants

> Gives the name of the stationfile eqcoda must read to set per-channel parameters; see pick_ew's station list format for field descriptions and examples. Eqcoda should read the same station file as pick_ew. Eqcoda uses only five of the fields of the station file: Station, Comp, Net (#3,4,5), CodaTerm (#19), and ClipCount (#23). The Station, Comp, Net fields identify the Station, Component, and Network codes of each channel. The CodaTerm field defines the coda termination level (counts) for each channel. The ClipCount field (added specifically for eqcoda, ignored by pick_ew) specifies the maximum amplitude (counts zero-to-peak) that can be expected for each channel. Eqcoda calculates clipping thresholds for P-amplitudes (KlipP1, KlipP2) and coda-window average absolute amplitudes (KlipC) as a fraction of ClipCount. See Notes on eqcoda's default values for its constants below for details.

> If the StaFile command is omitted, eqcoda will use the original global defaults (appropriate for 12-bit Earthworm analog data) for all channels. If a channel is not listed in stationfile, eqcoda will use the default parameters (appropriate for 12-bit Earthworm analog data) for that channel. If a channel is listed in stationfile, but the ClipCount field is missing, eqcoda will use DefaultClipCount=2048 (also appropriate for 12-bit Earthworm analog data) for that channel. On startup, eqcoda logs the parameters it will use for each channel, with an asterisk denoting default values.

> Pick_ew reports the first three peaks of the P-wave arrival. Eqcoda computes the average for its output message. If the first (of 3) P-amplitude exceeds KlipP1 counts, eqcoda considers it to be clipped. If the second or third P-amplitude exceed KlipP2, they are considered to be clipped. Eqcoda excludes any clipped values when calculating the average P-amplitude.

> Pick_ew reports coda duration as the time from the P-arrival to the time when the average absolute amplitude of a 2-second trace data window reaches CodaTerm counts. Pick_ew also reports the average absolute amplitudes of up to six 2-second coda windows. Eqcoda finds the slope of the coda decay by performing an L1 fit to the coda amplitudes, ignoring any coda amplitudes that precede the predicted S-wave arrival or that exceed that channel's coda clipping (KlipC) threshold. Eqcoda extrapolates the coda decay to a level of CodaTerm counts, estimating the coda duration for those picks that pick_ew has timed-out on (pick_ew waits a maximum of 144 seconds for the coda to reach the CodaTerm value).

> For extrapolated coda lengths to be consistent with "normally-terminating" (<144 sec) coda lengths reported by pick_ew, be sure that both modules read the same station file.

>     Default:  none
>     Example:  StaFile pick_ew.sta

## 4. NOTES ON EQCODA'S DEFAULT VALUES FOR ITS CONSTANTS

For historical perspective, most of eqcoda's code was originally written to handle Rex Allen RTP digitizer data which had an output range of +/- 2500 counts for an input signal of +/- 2.5 Volts. The Earthworm system uses a 12-bit A/D; so its output ranges from +/- 2048 counts for the same input signal of +/- 2.5 Volts.

       For Allen RTP digitizers,  1 mV = 1.0  counts
       For Earthworm digitizers,  1 mV = 0.82 counts

The constants used in eqcoda were originally defined for the RTP data to be "nice round numbers" of mV input to the digitizer. In eqcoda, the defaults for these constants have been converted for use with analog Earthworm data. They still correspond to the same input values; they just aren't "nice round numbers" any more.

       Original constants for Rex Allen RTP data:
        KlipC  = 1000 count = 0.40 max zero-to-peak amplitude
        KlipP1 = 1200 count = 0.48 max zero-to-peak amplitude
        KlipP2 = 1400 count = 0.56 max zero-to-peak amplitude

       Eqcoda's constants for 12-bit Earthworm data:
        KlipC  =  820 count
        KlipP1 =  984 count
        KlipP2 = 1148 count

Originally, eqcoda used a set of global constants for all channels because all data in the system was produced by the Earthworm digitizer. In Earthworm versions v5.1 and higher, eqcoda can be configured to use per-channel constants instead of the original global constants. To set per-channel constants, eqcoda must read a station list file, the same file that is read by pick_ew. Eqcoda uses 5 fields: station, component, network, CodaTerm, and ClipCount. The ClipCount field (added specifically for eqcoda, ignored by pick_ew) specifies the maximum amplitude (counts zero-to-peak) that can be expected for each channel. Eqcoda calculates each channel's three clipping constants by multiplying its ClipCount by the fractions used in the original definitions (see above). If the ClipCount field is omitted from the station file, eqcoda assumes the channel is a standard Earthworm analog channel from a 12-bit digitizer and it assigns a DefaultClipCount = 2048.

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