• Antelope Release 5.5 Linux 2.6.32-220.el6.x86_64 2015-04-21

 

NAME

sgnloc - command line interface to single event location code

SYNOPSIS

sgnloc inpf outpf

SUPPORT


Contributed code: NO BRTT support.
THIS PIECE OF SOFTWARE WAS CONTRIBUTED BY THE ANTELOPE USER COMMUNITY. BRTT DISCLAIMS ALL OWNERSHIP, LIABILITY, AND SUPPORT FOR THIS PIECE OF SOFTWARE.

FOR HELP WITH THIS PIECE OF SOFTWARE, PLEASE CONTACT THE CONTRIBUTING AUTHOR.

DESCRIPTION

sgnloc is a crude command line interface to a general purpose seismic event location code based on the standard Gauss-Newton method, commonly called Geiger's method in seismology. inpf is the input parameter file and is required. For this interface, it contains everything the program needs. However, for any real practical use the user should take advantage of the searching hierarchy of the parameter file procedures and place different pieces of many parameters required by sgnloc in different parts of the directory chain. (see genloc_intro for detailed descriptions of all the required parameters)

The program writes its results to an output file outpf. This output is itself a parameter file that can be parsed with the parameter file functions pfread, pfget_tbl, etc. outpf is keyed by three base parameter names, all of which are of type "Tbl":


convergence_history
convergence_criteria
residuals

convergence_history contains a dump of the stack of hypocenters that define the convergence history of the algorithm. The first entry in the list is the starting solution, and the last entry is the result when the program exited. Each line of the table contains the following parameters in the order listed:

where

lat0, lon0, t0, z0 - initial hypocenter
lat, lon, t, z - new location
dx, dy, dz, dt - adjustment vector in km (x=+East, y=+North, z=+down)
rms - L2 norm of raw residual vectors
wrms - L2 norm of weighted residual vectors (includes 1/error scaling)
iq - interquartile distance of weighted residual vector
n - number of data used in solution
ndf - number of degrees of freedom in solution

convergence_criteria contains a stack of simple phrases describing criteria used to break the iterative loop.

residuals contains a table of detailed residuals from the final solution. Each line in the table contains the following parameters in the order listed:

where

sta - observing station
phase - observed seismic phase
datatype - either "time", "ux", or "uy"
wr - weighted residual for this datum
r - raw residual for this datum
w - total weight for this datum
reswt - residual weight

PARAMETER FILE

see genloc_intro for details

EXAMPLE

This is an example output parameter file:

convergence_criteria	&Tbl{
    Correction vector is small.  L2 norm of final correction = 0.008480
}
convergence_history	&Tbl{
    30 80 5 7.12789e+08 30 80 5 7.12789e+08 0 0 0 -1 -1 -1 0 0
    30 80 5 7.12789e+08 37.1444 72.9395 5 7.12789e+08 -906.52 794.395 0 204.512 5.25504 512.508 10 7
    37.1444 72.9395 5 7.12789e+08 38.3408 74.2232 5 7.12789e+08 179.064 133.033 0 26.5402 0.681964 54.3727 10 7
    38.3408 74.2232 5 7.12789e+08 38.4843 74.4273 5 7.12789e+08 28.9335 15.9537 0 6.15092 0.158051 16.146 10 7
    38.4843 74.4273 5 7.12789e+08 38.5034 74.5472 5 7.12789e+08 17.0388 2.12657 0 5.7965 0.148944 12.8433 10 7
    38.5034 74.5472 5 7.12789e+08 38.5061 74.5996 5 7.12789e+08 7.44416 0.300409 0 5.71119 0.146752 12.7573 10 7
    38.5061 74.5996 5 7.12789e+08 38.5066 74.6202 5 7.12789e+08 2.92644 0.0479096 0 5.70062 0.14648 13.1264 10 7
    38.5066 74.6202 5 7.12789e+08 38.5066 74.628 5 7.12789e+08 1.11501 0.00671969 0 5.69933 0.146447 13.2519 10 7
    38.5066 74.628 5 7.12789e+08 38.5066 74.631 5 7.12789e+08 0.421213 0.000860497 0 5.69916 0.146443 13.2986 10 7
    38.5066 74.631 5 7.12789e+08 38.5066 74.6321 5 7.12789e+08 0.15874 7.05924e-05 0 5.69914 0.146442 13.3118 10 7
    38.5066 74.6321 5 7.12789e+08 38.5066 74.6325 5 7.12789e+08 0.0597964 -1.69035e-05 0 5.69914 0.146442 13.3096 10 7
    38.5066 74.6325 5 7.12789e+08 38.5066 74.6327 5 7.12789e+08 0.022507 -2.03867e-05 0 5.69914 0.146442 13.3087 10 7
    38.5066 74.6327 5 7.12789e+08 38.5066 74.6328 5 7.12789e+08 0.00848018 9.90927e-06 0 5.69914 0.146442 13.3084 10 7
}
residuals	&Tbl{
    CHM P time 3.45865 0.0968421 35.7143 1
    KBK P time -2.38873 -0.0668845 35.7143 1
    TKM P time 3.52908 0.0494071 71.4286 1
    USP P time -11.07 -0.42066 26.3158 1
    CHM S time -20.6925 -4.13849 5 1
    KBK S time -14.2923 -2.85846 5 1
    TKM S time -12.8075 -2.56151 5 1
    USP S time 47.9423 9.58845 5 1
    TKM P ux -0.631143 -0.00631143 100 1
    TKM P uy 0.0941304 0.000941304 100 1
}

DIAGNOSTICS

Numerous possible error messages are possible. The program uses Dan Quinlan's error routines (complain, die, and register_error) which write to stderr by default, but can be diverted to a log file if desired. See the man pages on ggnloc and genloc for a list of most diagnostics

SEE ALSO

genloc(3), genloc_intro(3), ggnloc(3), pfread(3)

BUGS AND CAVEATS

Although sgnloc is a simple interface, the program it drives is complex with a large number of options that can produce wildly different behavior. See man genloc_intro for more details on specific parameters.

AUTHOR

Gary L. Pavlis
Antelope User Group Contributed Software
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