There are three SEISAN response formats. The instrument response can either be presented as (1) instruments constants, (2) pairs of frequency amplitude and phase or as (3) poles and zeros.
Line 1 1 5: STATION CODE (A5) 6 9: COMPONENT (A4), E.G. SZ L : SZ LOW GAIN, AN: ACCELERATION NS 10 : CENTURY, 0: 1900, 1:2000 11 12: YEAR 14 16: DOY 18 19: MONTH 21 22: DAY 24 25: HR 27 28: MIN 30 35: SECOND (F6.3) 52 59: LATITUDE (F8.4), optional 61 69: LONGITUDE (F9.4), optional 71 75: ELEVATION (METERS), optional 78 : P: Poles and zeros Blank: Seismometer period etc used for response info. See below for details. T: Use up to 30 tabulated values irrespective of what is given below. If less than 30, blank characters must be given. 79 : C: a combination of table, poles and zeros or instrument constants have been used, for information only. Value in 78 must then be T. F: Force use of header response. Only gain at 1 hz is correct and 78 must be set to T. Line 2 1 80: COMMENT LINE DESCRIBING THE SYSTEM RESPONSE (A80) OPTION 1 If character 78 is blank, option 1: Line 3 1 - 80: (10G8.3) 1. SEISMOMETER PERIOD 2. FRACTION OF CRITICAL DAMPING 3. SEISMOMETER GENERATOR CONSTANT (V/m/s) or ACCELEROMETER SENSITIVITY (V/G) 4. AMPLIFIER GAIN 5. RECORDING MEDIA GAIN (I.E. 2048 COUNTS/VOLT) 6. GAIN AT 1.0 HZ, UNITS: COUNTS/METER 7. CUTOFF FREQUENCY FOR FILTER1 (HZ) 8. # OF POLES FOR FILTER1 (NEGATIVE FOR HIGHPASS) 9. CUTOFF FREQUENCY FOR FILTER2 (HZ) 10. # OF POLES FOR FILTER2 (NEGATIVE FOR HIGHPASS) Line 4 1 - 80: (10G8.3) FREQUENCIES AND #'S OF POLES FOR FIVE MORE FILTERS Lines 5-13: RESPONSE CURVE in 3 blocks of 3 lines 1 - 80: (10G8.3) FREQ. 1 - 80: (10G8.3) AMPL. (REL. 1.0 HZ) 1 - 80: (10G8.3) PHASE, The are only for info in option 1 OPTION 2 If character 78 is T, use tablated values, format as in option 1 OPTION 3 If character 78 is P, option 2: Line 3 1 - 22: (1X,2I5,G11.4) 1. NUMBER OF POLES 2. NUMBER OF ZEROS 3. NORMALIZATION CONSTANT, COUNTS/M 23 - 80 (5G11.4) 2 Poles in pairs of real and imaginary parts Lines 4-13 1 - 80: (G11.4) Remaining poles and zeros. 7 values are written and then 3 spaces are left blank.
Example of SEISAN FAP response file
KBS B Z100 1 1 1 0 0 0.000 360. .700 .260E+04 0. .419E+06.684E+10 0. 0.000 0. 0.000 0. 0.00 0. 0.00 0. 0.00 0. 0.00 0. 0.00 .500E-02.700E-02.980E-02.140E-01.190E-01.270E-01.370E-01.520E-01.730E-01.100 .480E-02.694E-02.978E-02.140E-01.190E-01.270E-01.370E-01.520E-01.730E-01.100 138.366 123.400 113.340 106.128 101.813 98.283 96.034 94.289 93.054 92.229 .140 .200 .280 .390 .550 .770 1.10 1.50 2.10 2.90 .140 .200 .280 .390 .550 .770 1.10 1.50 2.10 2.90 91.592 91.114 90.796 90.571 90.405 90.289 90.203 90.149 90.106 90.077 4.10 5.80 8.10 11.0 16.0 22.0 31.0 43.0 60.0 85.0 4.10 5.80 8.10 11.0 16.0 22.0 31.0 43.0 60.0 85.0 90.054 90.038 90.028 90.020 90.014 90.010 90.007 90.005 90.004 90.003
Example of SEISAN PAZ response file using the same constants as above
KBS B Z100 1 1 1 0 0 0.000 P 2 3 0.1089E+10-0.1222E-01 0.1246E-01-0.1222E-01-0.1246E-01 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.