Each line of a .lsd file consists of either a comment, or a keyword and its parameters.
A Keyword Line consist of several tokens (strings or numbers) that are separated by whitespace (the space character [ASCII 32] or Tab stops [ASCII 9]). The line begins with the Keyword itself, which may be followed by a Keyword Modifier and then a number of Keyword Parameters:
!Keyword !Modifier parameter parameter parameter
The Exclamation mark "!" is used to distinguish Keywords and Modifiers from parameters. The possible Modifiers and the allowed number of parameters depend on the Keyword.
A consequence of the use of whitespace as parameter separator are certain limitations to string parameters: only one string parameter per keyword is possible, since strings may consist of several words which are also separated by whitespace, and a string parameter also has to be the last parameter of a multi-parameter keyword.
A simple example is
!arrival !baz 40 45
where "arrival" is the keyword and "baz" is the modifier. "40 45" are numeric parameters. This example line defines some Back Aimzuith angle to be in the interval 40...45 (in implied units, see section on units in Tutorial).
Another example is
!station !start Klaus
Where "station" is the keyword, "start" is a modifier and "Klaus" is a string parameter. This example defines the name of a station to be "Klaus" and begins a station description block.
The following tables give a list of all Keywords, their Modifiers and the specified Parameters. (The sequence in which the two or three numbers that specify a value are given, is not relevant. See section on parameter model.)
List of all Keywords:
Modifier | Parameter | Type | Explanation |
---|---|---|---|
start | station identifier | string | Station record start tag. The parameter is an arbitrary string used to identify the station |
end | none | - | Travel Time record end tag |
lon | value | numeric | Station longitude |
lat | value | numeric | Station latitude |
elev | value | numeric | Station elevation |
Modifier | Parameter | Type | Explanation |
---|---|---|---|
start | event identifier | string | Event constraint start tag. The parameter is an arbitrary string used to identify the event |
end | none | - | Travel Time record end tag |
info | event info | string | arbitrary string giving additional event info. |
lon | 1. minimum value 2. maximum value (3. mean value) |
numeric | Longitude constraint: event location is constrained to this longitude interval by external evidence |
lat | 1. minimum value 2. maximum value (3. mean value) |
numeric | Latitude constraint: event location is constrained to this latitude interval by external evidence |
depth | 1. minimum value 2. maximum value (3. mean value) |
numeric | focal depth constraint: event location is constrained to this focal depth interval by external evidence (depth is zero for meteorites!) |
ot | 1. minimum value 2. maximum value (3. mean value) |
numeric | Origin time constraint: event origin time is constrained to this time interval by external evidence |
Modifier | Parameter | Type | Explanation |
---|---|---|---|
start | record ID | string | Raw data record start tag. The parameter is an arbitrar string used to identify the data record. |
end | none | - | Raw data record end tag |
station | station identifier | string | an arbitrary string, interpreted as station identifier. Does not necessarily correspond to a station identified by a station keyword in the same file. |
event | event ID | string | an arbitrary string, interpreted as event identifier. Does not necessarily correspond to a station identified by a event keyword in the same file. |
phase | phase name | string | a seismic phase name |
at | 1. minimum value 2. maximum value (3. mean value) |
numeric | Phase Arrival Time |
baz | 1. minimum value 2. maximum value (3. mean value) |
numeric | Back Azimuth inferred from Phase polarization |
emerg | 1. minimum value 2. maximum value (3. mean value) |
numeric | Emergence angle inferred from Phase polarization |
slo | 1. minimum value 2. maximum value (3. mean value) |
numeric | Slowness inferred from Phase polarization, surface velocity and/or other data |