File formats
PStomo has 3 basic input files (in addition to the parameter file and the initial/starting model):
- station file: contains station coordinates in cartesian (flat Earth) projection
- source file: contains origin time and hypocenter of sources (earthquakes and/or controlled) in cartesian projection
- arrival time file: contains arrival times of P (and S) waves sorted by recording station
Although it is not necessary, we follow this convention for naming the input files:
- all files have a
.inextension - all files begin with a common prefix, which is a short identifier of the project or region
(e.g.
icefor Iceland orncalfor Northern California) - station file has the
_statsuffix (e.g.ice_stat.in) - source file has the
_srcsuffix (e.g.ice_src.in) - arrival time file has the
_ttsuffix (e.g.ice_tt.in)
Since we often have many more sources than stations, to reduce computing time inside PStomo
travel times are calculated from the stations. Therefore the concept of source and receiver is
reversed inside the code.
Station list
A station file contains lines with the following columns (one for each station):
STATION_ID X Y Z MAX_DISTANCE NUMBER_ARRIVAL_TIMES USE_STATION FLAG STATION_CODE
STATION_ID= numerical station ID (not passed to main)X= x coordinate in kmY= y coordinate in kmZ= z coordinate in km (negative if above sea level)MAX_DISTANCE= distance (km) to furthest source recorded by this station (not passed to main)NUMBER_ARRIVAL_TIMES= number of arrival times for this stationUSE_STATION= use flag: 0 use, 1 do not use (WARNING: opposite to standard true/false convention)FLAG= additional flag (not passed to main)STATION_CODE= alphanumeric station code (not passed to main)
0 -33.59028 -4.31897 -0.79400 116.72459 1225 0 0 CADE
1 -42.17252 12.75307 -1.16000 150.92570 854 0 0 CBOL
2 -20.12271 2.41153 -2.21000 101.10428 2142 0 0 CCAN
3 -26.79712 2.82335 -2.06400 94.74211 1168 0 0 CCHO
4 -15.59873 9.43089 -2.10300 109.41433 827 0 0 CDIE
5 -33.25449 10.47509 -1.62600 111.62872 962 0 0 CDOS
6 -18.92852 12.64890 -2.11000 108.85104 762 0 0 CFOR
Source locations
A source file contains lines with the following columns (one for each source):
SOURCE_ID YYMMDD HHMM SS.FF... X Y Z MAGNITUDE EVENT_TYPE EVENT_GROUP_ID FLAG
SOURCE_ID= source number/ID (usually starts at 0 but not required?)YYMMDD= origin time year, month, and day for this source (WARNING: two-digit year)HHMM= origin time hour and minute for this sourceSS.FF...= origin time seconds and fractionary part (variable precision)X= x coordinate in kmY= y coordinate in kmZ= z coordinate/focal depth in km (negative if above sea level)MAGNITUDE= event magnitudeEVENT_TYPE= 0 for earthquakes, 1 for explosions (controlled source)EVENT_GROUP_ID= event group ID this source belongs to (if no event groupsSOURCE_ID = EVENT_GROUP_ID)FLAG= (passed to main but apparently not used)
0 040628 0342 29.90 -29.3320 9.4560 0.0000 1.90 0 0 0
1 040628 0423 48.20 -29.9220 9.0140 0.0000 1.90 0 1 0
2 040629 2125 53.40 -16.4760 13.3100 0.0000 2.70 0 2 0
3 040706 1855 57.60 -28.3670 2.8040 0.0000 1.70 0 3 0
4 040716 2152 3.70 -34.7100 15.7880 24.5000 1.60 0 4 0
5 040725 0059 41.60 -29.5290 9.2350 0.0000 1.80 0 5 0
6 040727 0514 10.60 -22.9390 18.6410 16.4000 2.40 0 6 0
7 040727 0514 44.40 -27.5580 13.5530 5.1000 2.60 0 7 0
8 040727 0531 10.50 -28.0430 15.2170 8.4000 1.80 0 8 0
9 040727 1747 38.80 -30.6180 5.6910 0.0000 1.40 0 9 0
10 040728 0029 27.00 -28.6480 9.0110 0.0000 1.60 0 10 0
11 040730 1111 51.00 -29.1360 9.6770 0.0000 2.50 0 11 0
Arrival times
The arrival time file contains two types of lines:
Station line
The arrival time file must begin with a station line and must contain exactly as many station lines as stations listed in the station file (and in the same order).
STATION_CODE NUMBER_ARRIVAL_TIMES
STATION_CODE= station code (program does not check that it coincides with code in station file)NUMBER_ARRIVAL_TIMES= number of arrival times for this station (this exact same of number of arrival time lines must follow this station line)
Arrival time line
SOURCE_ID YYMMDD HHMM P_SECOND P_WEIGHT P_USE S_SECOND S_WEIGHT S_USE
SOURCE_ID= source ID in source file this arrival time belongs toYYMMDD= year, month and day of arrival time (WARNING: two-digit year)HHMM= hour and minute of arrival timeP_SECOND= second of P-wave arrival timeP_WEIGHT= weight of P-wave arrival time (HYPO71 convention: 0 = full weigth, > 3 = do not use)P_USE= flag for using this P phase: 0 = use, > 0 do not use (WARNING: opposite to standard true/false convention)S_SECOND= second of S-wave arrival time (can be greater than 60 s if S arrival time does not occur in same minute as P arrival time). If S phase is not present thenS_SECOND = 0.0andS_WEIGHT = S_USE = 9.S_WEIGHT= weight of S-wave arrival time (HYPO71 convention: 0 = full weigth, > 3 = do not use)S_USE= flag for using this S phase: 0 = use, > 0 do not use (WARNING: opposite to standard true/false convention)
Although the station file lists STATION_ID and STATION_CODE, these values are not used nor
checked against the values in the arrival time file. Instead the program assumes
that the stations in the arrival time file appear in exactly the same order as in the station file.
However NUMBER_ARRIVAL_TIMES in the arrival time file and in the station file must be the same,
and is verified by the program.
CADE 1225
371 170401 1657 10.550 1 0 17.120 2 0
372 170406 2350 7.840 1 0 9.660 2 0
373 170408 0846 17.160 1 0 0.000 9 9
374 170623 2148 26.150 1 0 28.430 2 0
375 170410 0101 14.790 1 0 20.740 2 0
378 170421 0450 26.430 1 0 33.150 2 0
379 170422 1416 25.160 1 0 30.520 2 0
380 170423 1932 12.340 1 0 14.430 2 0
381 170424 0201 31.170 1 0 32.550 2 0
386 170513 0126 30.780 1 0 33.070 2 0
389 170523 0029 22.760 1 0 24.840 2 0
.
.
.
2223 200406 2219 54.000 1 0 55.910 2 0
2224 200407 0335 37.460 1 0 42.790 2 0
2225 200407 2359 52.180 1 0 53.150 2 0
2226 200408 0612 20.060 1 0 25.330 2 0
CBOL 854
330 160803 2230 50.560 1 0 57.750 2 0
331 160831 0734 26.290 1 0 34.960 2 0
332 160927 2347 53.610 1 0 61.520 2 0
335 161003 1340 49.230 1 0 58.740 2 0
.
.
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