NonLinLoc

NonLinLoc locator wrapper plugin for SeisComP. NonLinLoc was written by Anthony Lomax (http://alomax.free.fr/nlloc).

Description

Funded by SED/ETH Zurich, developed by gempa GmbH. This plugin is available from SeisComP version Release Potsdam 2010 and later.

The NonLinLoc (NLL) locator algorithm has been implemented into SeisComP through the plugin mechanism. A new plugin locnll contains the LocatorInterface implementation for NonLinLoc.

The implementation bundles the NonLinLoc source files required to use the library function calls. The following source files are included:

GridLib.c
GridLib.h
GridMemLib.c
GridMemLib.h
NLLocLib.h
NLLoc1.c
NLLocLib.c
calc_crust_corr.c
calc_crust_corr.h
crust_corr_model.h
crust_type_key.h
crust_type.h
loclist.c
octtree.h
octtree.c
phaseloclist.h
phaselist.c
geo.c
geo.h
geometry.h
map_project.c
map_project.h
otime_limit.c
otime_limit.h
ran1.c
ran1.h
velmod.c
velmod.h
util.h
util.c
alomax_matrix/alomax_matrix.c
alomax_matrix/alomax_matrix.h
alomax_matrix/alomax_matrix_svd.c
alomax_matrix/alomax_matrix_svd.h

Error measures

After running NonLinLoc the output is converted into a SeisComP (QuakeML) origin object including all available error measures. The following table shows how the NLL error measures are mapped to the SeisComP data model:

SeisComP

NLL

Origin.latitude.uncertainty

sqrt(phypo->cov.yy)

Origin.longitude.uncertainty

sqrt(phypo->cov.xx)

Origin.depth.uncertainty

sqrt(phypo->cov.zz)

Origin.originQuality.standardError

phypo->rms

Origin.originQuality.secondaryAzimuthalGap

phypo->gap_secondary

Origin.originQuality.usedStationCount

phypo->usedStationCount

Origin.originQuality.associatedStationCount

phypo->associatedStationCount

Origin.originQuality.associatedPhaseCount

phypo->associatedPhaseCount

Origin.originQuality.usedPhaseCount

phypo->nreadings

Origin.originQuality.depthPhaseCount

phypo->depthPhaseCount

Origin.originQuality.minimumDistance

km2deg(phypo->minimumDistance)

Origin.originQuality.maximumDistance

km2deg(phypo->maximumDistance)

Origin.originQuality.medianDistance

km2deg(phypo->medianDistance)

Origin.originQuality.groundTruthLevel

phypo->groundTruthLevel

Origin.originUncertainty.horizontalUncertainty

phypo->ellipse.len2

Origin.originUncertainty.minHorizontalUncertainty

phypo->ellipse.len1

Origin.originUncertainty.maxHorizontalUncertainty

phypo->ellipse.len2

Origin.originUncertainty.azimuthMaxHorizontalUncertainty

phypo->ellipse.az1 + 90

ConfidenceEllipsoid.semiMajorAxisLength

phypo->ellipsoid.len3

ConfidenceEllipsoid.semiMinorAxisLength

phypo->ellipsoid.len1

ConfidenceEllipsoid.semiIntermediateAxisLength

phypo->ellipsoid.len2

ConfidenceEllipsoid.majorAxisPlunge

(phypo->ellipsoid.axis1 x phypo->ellipsoid.axis2).dip

ConfidenceEllipsoid.majorAxisAzimuth

(phypo->ellipsoid.axis1 x phypo->ellipsoid.axis2).az

ConfidenceEllipsoid.majorAxisRotation

T.B.D.

Plugin

The NonLinLoc plugin is installed under share/plugins/locnll.so. It provides a new implementation of the LocatorInterface with the name NonLinLoc.

To add the plugin to a module add it to the modules configuration, either modulename.cfg or global.cfg:

plugins = ${plugins}, locnll

Basically it can be used by two modules: screloc and scolv.

Output

All output is stored in the configured NonLinLoc.outputPath. The file prefix for a location is the originID (NonLinLoc.publicID).

The following file are stored:

  • Input observations (.obs)

  • Input configuration (.conf)

  • NLL location (.loc.hyp)

  • NLL 3D grid header (.loc.hdr)

  • NLL octree (.loc.octree)

  • NLL scatter file (.loc.scat)

In addition to the native NLL output a SeisComP origin object is created and returned to the calling instance. Usually this object is then sent via messaging.

Configuration example

To add the plugin to an application such as scolv or screloc, add the plugin name to the list of plugins that are loaded (e.g. scolv.cfg):

plugins = ${plugins}, locnll

Futhermore add the plugin configuration (e.g. scolv.cfg):

########################################################
################ NonLinLoc configuration################
########################################################
NLLROOT = ${HOME}/nll/data

NonLinLoc.outputPath = ${NLLROOT}/output/

# Define the default control file if no profile specific
# control file is defined.
NonLinLoc.controlFile = ${NLLROOT}/NLL.default.conf

# Set the default pick error in seconds passed to NonLinLoc
# if no SeisComP pick uncertainty is available.
NonLinLoc.defaultPickError = 0.1

# Define the available NonLinLoc location profiles. The order
# implicitly defines the priority for overlapping regions
#NonLinLoc.profiles = swiss_3d, swiss_1d, global
NonLinLoc.profiles = swiss_3d, global

# The earthModelID is copied to earthModelID attribute of the
# resulting origin
NonLinLoc.profile.swiss_1d.earthModelID = "swiss regional 1D"

# Specify the velocity model table path as used by NonLinLoc
NonLinLoc.profile.swiss_1d.tablePath = ${NLLROOT}/time_1d_regio/regio

# Specify the region valid for this profile
# Without this parameter the plugin will add an additional
# TRANS GLOBAL statement in the NLL control file
NonLinLoc.profile.swiss_1d.region = 41.2, 3.8, 50.1, 16.8

# The NonLinLoc  control file to use for this profile
NonLinLoc.profile.swiss_1d.controlFile = ${NLLROOT}/NLL.swiss_1d.conf

# Configure the swiss_3d profile
NonLinLoc.profile.swiss_3d.earthModelID = "swiss regional 3D"
NonLinLoc.profile.swiss_3d.tablePath = ${NLLROOT}/time_3d/ch
NonLinLoc.profile.swiss_3d.region = 45.15, 5.7, 48.3, 11.0
NonLinLoc.profile.swiss_3d.controlFile = ${NLLROOT}/NLL.swiss_3d.conf

# And the global profile
NonLinLoc.profile.global.earthModelID = iaspei91
NonLinLoc.profile.global.tablePath = ${NLLROOT}/iasp91/iasp91
NonLinLoc.profile.global.controlFile = ${NLLROOT}/NLL.global.conf

An example of a NonLinLoc control file configuration that contains all the required statements, but it must be adapted to the specific use case. The missing statements are generated by the plugin (LOCFILES, LOCHYPOUT, LOCSRCE):

# -1 = no logs, useful for playback with screloc --ep option
CONTROL -1 123456
# This must be the same TRANS used for generating the grid files
TRANS SDC 46.51036987 8.47575546 0.0
LOCSIG Swiss Seismological Service, ETHZ
LOCCOM location using my local velocity model
LOCSEARCH OCT 20 20 20 0.001 10000 1000
# This grid origin is relative to the TRANS statement. The grid
# must be wholly contained in the grid files
LOCGRID 101 101 101 -0.5 -0.5 -1.8  0.01 0.01 0.01 PROB_DENSITY SAVE
LOCMETH EDT_OT_WT 9999.0 4 -1 -1 -1 0 -1 1
LOCGAU 0.001 0.0
LOCPHASEID  P   P p G Pn Pg P1
LOCPHASEID  S   S s G Sn Sg S1
LOCQUAL2ERR 0.025 0.050 0.100 0.200 0.400 99999.9
LOCANGLES ANGLES_YES 5

Stations names

When generating the grid files the station names used in the GTSRCE statement must match the rule set in the plugin configuration. E.g.

# Format of the station name used to select the right travel time table (grid)
# file for a station. By default only the station code is used (e.g.
# tablePath.P.@STA@.time.*), but that doesn't allow to distinguish between
# multiple network codes or location codes that use the same station code. To
# overcome this limitation this parameter could be set in a more general way,
# for example @NET@_@STA@_@LOC@. In this way NonLinLoc will look for travel
# time table (grid) files of the form: tablePath.P.@NET@_@STA@_@LOC@.time.*
# Where @NET@ @STA@ @LOC@ are just placeholder for the actual codes
NonLinLoc.profile.MYPROFILE.stationNameFormat = @NET@_@STA@_@LOC@

Given the above plugin configuration, the GTSRCE statement should be something like this:

GTSRCE CH_STA01_   LATLON  46.519  8.474  0.0  1.295
GTSRCE CH_STA02_01 LATLON  46.456  8.474  0.0  1.323
GTSRCE CH_STA03_AA LATLON  46.784  8.474  0.0  1.292

Alternatively the names could just contain the station code:

NonLinLoc.profile.MYPROFILE.stationNameFormat = @STA@
GTSRCE STA01 LATLON  46.519  8.474  0.0  1.295
GTSRCE STA02 LATLON  46.456  8.474  0.0  1.323
GTSRCE STA03 LATLON  46.784  8.474  0.0  1.292

Usage

Locator

The usage of the new NLL plugin is straight forward. Once loaded successfully the new locator shows up in the lower left corners combo box.

../_images/locator_selection_small1.png

Select the new NonLinLoc locator and the configured profiles will be loaded into the combo box right of it.

../_images/locator_profile_selection_small1.png

The NonLinLoc implementation provides a virtual profile automatic. This emulates the complete automatic case and selects the best matching configured profiles based on the initial location.

If an origin has been relocated the method should be set to “NonLinLoc” and the earth model contains the string NonLinLoc.profile.[name].earthModelID configured for the selected profile.

../_images/origin_information1.png

Settings

The NLL locator implementation supports to override configured settings or control parameters for a session. Those changes are not persistent and lost if the locator is changed to another one or the profile has been changed.

To open the settings dialog press the button right to the locator selection combo box.

../_images/locator_settings1.png

Then the NLL specific parameters show up.

../_images/NLL_settings.png

Seismicity Viewer

scolv provides two additional configurable buttons. To bind Seismicity Viewer to the first one the following configuration can be used:

button0 = "Seismicity Viewer"
scripts.script0 = @CONFIGDIR@/scripts/sv

A small wrapper script sv has been created that calls Seismicity Viewer based on the origin ID passed to the script.

#!/bin/sh
FILE=$HOME/nll/data/output/$1.loc.hyp
java -classpath $HOME/nll/bin/SeismicityViewer50.jar \
     net.alomax.seismicity.Seismicity $FILE

This examples assumes that Seismicity Viewer has been installed in $HOME/nll/bin.

Module Configuration

NonLinLoc.publicID

Type: string

PublicID creation pattern for an origin created by NonLinLoc. Default is NLL.@time/%Y%m%d%H%M%S.%f@.@id@.

NonLinLoc.outputPath

Type: path

Defines the output path for all native NonLinLoc input and output files. Default is /tmp/sc3.nll.

NonLinLoc.saveInput

Type: boolean

Save input files *.obs in outputPath for later processing. Setting to false reduces file i/o and saves disk space. Default is true.

NonLinLoc.saveIntermediateOutput

Type: boolean

Save output files in outputPath for later processing or for viewing by the Seismicity Viewer. Setting to false reduces file i/o and saves disk space. Default is true.

NonLinLoc.controlFile

Type: path

The default NonLinLoc control file to use.

NonLinLoc.defaultPickError

Type: double

Unit: s

The default pick error in seconds passed to NonLinLoc if a SeisComP pick object does not provide pick time uncertainties. Default is 0.5.

NonLinLoc.fixedDepthGridSpacing

Type: double

Unit: km

Since NLL does not support fixing the depth natively so this feature is emulated by settings the Z grid very tight around the depth to be fixed. This value sets the Z grid spacing. Default is 0.1.

NonLinLoc.allowMissingStations

Type: boolean

Picks from stations with missing configuration will be ignored. The origin will be relocated without that pick if possible.

If set to false, the plug-in throws an excepection without locating. Default is true.

NonLinLoc.profiles

Type: list:string

Defines a list of active profiles to be used by the plugin.

Note

NonLinLoc.profile.$name.* Defines a regional profile that is used if a prelocation falls inside the configured region. $name is a placeholder for the name to be used and needs to be added to NonLinLoc.profiles to become active.

NonLinLoc.profiles = a,b
NonLinLoc.profile.a.value1 = ...
NonLinLoc.profile.b.value1 = ...
# c is not active because it has not been added
# to the list of NonLinLoc.profiles
NonLinLoc.profile.c.value1 = ...
NonLinLoc.profile.$name.earthModelID

Type: string

earthModelID that is stored in the created origin.

NonLinLoc.profile.$name.methodID

Type: string

methodID that is stored in the created origin. Default is NonLinLoc.

NonLinLoc.profile.$name.tablePath

Type: path

Path to travel time tables (grids).

NonLinLoc.profile.$name.stationNameFormat

Type: string

Format of the station name used to select the right travel time table (grid) file for a station. By default only the station code is used (e.g. tablePath.P.@STA@.time.*), but that doesn’t allow to distinguish between multiple network codes or location codes that use the same station code. To overcome this limitation this parameter could be set in a more general way, for example @NET@_@STA@_@LOC@. In this way NonLinLoc will look for travel time table (grid) files of the form: tablePath.P.@NET@_@STA@_@LOC@.time.* Where @NET@ @STA@ @LOC@ are just placeholder for the actual codes Default is @STA@.

NonLinLoc.profile.$name.controlFile

Type: path

Control file of the current profile. If not set, the default control file will be used instead.

NonLinLoc.profile.$name.transform

Type: string

Transformation type of the configured region. Supported are SIMPLE and GLOBAL.

Default: GLOBAL is assumed. Default is GLOBAL.

NonLinLoc.profile.$name.region

Type: list:double

Defines the 4 corner values of the epicentral region for selecting the profile. The original epicentre must be within the region.

If transform is GLOBAL: min_lat, min_lon, max_lat, max_lon. The values define the geographic corner coordinates. Unit is degree.

If transform is SIMPLE: xmin, ymin, xmax, ymax. The values define the region relative to the configured origin. Unit is km.

NonLinLoc.profile.$name.origin

Type: list:double

Unit: deg

Only used for transformation SIMPLE. Expects 2 values: latitude, longitude. The value define the geographic origin of the area spanned by region. Unit is degree.

NonLinLoc.profile.$name.rotation

Type: double

Unit: deg

Only used for transformation SIMPLE. Defines the rotation around the origin of the defined region.