LSD structure

A LSD (Locsmith Seismic Data) structure defines the data set used for the location of an event. It is the output of MKLSREADLSD, and thus contains all data given in a .lsd file. It is a self contained set of data that may go directly into the location.

LSD structures consist of the following fields

  1. statcnt
  2. eventcnt
  3. rawcnt

and sub-structures

  1. station, for station descriptions
  2. event, for Event definitions
  3. arrival, for phase arrival data, referring to stations and events.

LSD structures use numeric intervals for most data: The data is not represented by a "mean" value and a uncertainty, but by an interval which encompasses the true value. Such numeric intervals consist of two to three numbers, denoting the lower and upper bound of the interval and optionally a "likely to be true" value.

Numeric Intervals are stored in three element vectors. The first element denotes the lower bound, the second the upper bound value and the third element is the "likely to be true" value, which might be NaN. (the third value is ignored anyway)

Undefined strings are empty.
Undefined numeric scalars are NaN.
Undefined numeric intervals are [NaN NaN NaN].

LSD structure
Field Type Units Description
statcnt numeric scalar - number of stations defined in STATION sub structure
eventcnt numeric scalar - number of events defined in EVENT sub structure
arrivalcnt numeric scalar - number of arrival data records defined in ARRIVAL sub structure
station array of sub structures - defines name and location of all stations
see sub structure definition for details.
event array of sub structures - defines name and locations of all events used
see sub structure definition for details.
arrival array of sub structures - defines arrival data: arrival times, azimuths, etc
see sub structure definition for details.
STATION sub structure
Field Type Units Description
id string - Station Identifier string
lon numeric interval ° station longitude
lat numeric interval ° station latitude
elev numeric interval km station elevation above reference sphere
EVENT sub structure
Field Type Units Description
id string - Event identifier string
info string - a string containing informal additional info
lon numeric interval ° event location constraint from external evidence
lat numeric interval ° event location constraint from external evidence
depth numeric interval km event location constraint from external evidence
ot numeric interval s event origin time constraint from external evidence
ARRIVAL sub structure
Field Type Units Description
id string - data record identifier
station string - identifier of station at which the data was observed
event string - identifier of event with which data is associated
phase string - seismic phase name: the phase to which the observation is associated
at numeric interval s arrival time of phase
baz numeric interval ° direction from which the phase arrived, measured from wave polarization
emerg numeric interval ° steepness with which phase comes out of the bottom, measured from wave polarization
slo numeric interval s/° Slowness of phase, measured from polarization and surface velocity or by station array.

eof.