Locators

Locators receive phase picks from modules such as scautoloc, screloc or scolv for locating seismic or non-seismic sources. The solutions may include source time and location with or without uncertainties. They are used to form new origins which can be treated further.

SeisComP ships with built-in locators:

and a none built-in locator:

While the built-in locators are well defined and documented, any other external locator routine can be added to SeisComP by configuration of the locator LocExt and custom scripts. LOCSAT and FixedHypocenter are native to SeisComP. All other locators are implemented as plugins. A plugin needs to be added to the list of loaded plugins by configuration of the global parameter plugins for making the corresponding locator available to SeisComP applications.

A comparison of the locators is given in the table below.

Note

The specifications given below may depend on the configuration of the respective locator. Please carefully read the documentation of the locators for optimizing their performance.

FH

Hypo71

iLoc

LocExt

LOCSAT

NonLinLoc

StdLoc

Applications

phases considered by default

seismic / infrasound

seismic

seismic / infrasound / hydroacoustic

[3]

seismic / infrasound

seismic

seismic

distance ranges of application

local / regional / teleseismic

local / regional

local / regional / teleseismic

[3]

local / regional / teleseismic

local / regional / teleseismic

local / regional [4]

application with default configuration

regional / teleseismic

❌

regional / global

[3]

regional / teleseismic

❌

local / regional [1]

Algorithm

inversion algorithm

linear

iterative

configurable

[3]

grid search

probabilistic

configurable

automatic phase renaming

❌

❌

✅

[3]

❌

❌

❌

considers network code

✅

❌

✅

[3]

✅

✅ [1]

✅

positive station elevation

✅ [2/4]

✅

✅

[3]

✅ [2]

✅

✅

negative station elevation

❌

✅

✅

[3]

❌

✅

✅

considers pick time

✅

✅

✅

[3]

✅

✅

✅

considers pick slowness

❌

❌

✅

[3]

✅

❌

❌

considers pick backazimuth

❌

❌

✅

[3]

✅

❌

❌

speed

fast

fast

fast - intermediate

[3]

fast

intermediate

fast - intermediate

Velocity model

velocity model

1D [4]

1D

1D

[3]

1D

1D / 3D

1D / 3D [4]

independent Vp and Vs

✅ [4]

❌

✅

[3]

✅

✅

✅ [4]

default velocity model

iasp91 / tab

❌

iasp91 / ak135

[3]

iasp91 / tab

❌

iasp91 / tab [1]

applies RSTT

❌

❌

✅

[3]

❌

❌

❌

Hypocenter solution

inverts for hypocenter location

❌

✅

✅

[3]

✅

✅

✅

inverts for hypocenter time

✅

✅

✅

[3]

✅

✅

✅

supports negative source depth

❌

✅

❌

[3]

❌

✅

✅

Configuration

native or plugin to load

✅

hypo71

lociloc

locext

✅

locnll

stdloc

SeisComP provides locator

✅

✅

✅

❌

✅

✅

✅

operates without external files

✅

❌

❌

❌

✅

❌

✅

operates without custom scripts

✅

✅

✅

❌

✅

✅

✅

Others

remarks

intended for ground-truth tests / single-station location / any travel-time interface

operational at EMSC and ISC (earlier version)

any external locator can be called by a custom script

currently the fastest locator in SeisComP and the only one available to scautoloc

considers model uncertainties

uses travel-times from any travel-time interface

point of contact

SeisComP forum [24]

SeisComP forum [24]

ibondar2014 @gmail.com

SeisComP forum [24]

SeisComP forum [24]

SeisComP forum [24]

SeisComP forum [24]

  • [1]: requires initial or specific configuration

  • [2]: requires correction file

  • [3]: depends on selected locator

  • [4]: depends on selected travel-time interface