segy.h

Go to the documentation of this file.

/* Copyright (c) Colorado School of Mines, 2011.*/
/* All rights reserved.                       */

/* This header file is part of the Seismic Unix (SU) package. 
 * For license information please see the file 
 * LEGAL_STATEMENT_segy_h.
 */

/* segy.h - include file for SEGY traces
 *
 * declarations for:
 *      typedef struct {} segy - the trace identification header
 *      typedef struct {} bhed - binary header
 *
 * Note:
 *      If header words are added, run the makefile in this directory
 *      to recreate hdr.h.
 *
 * Reference:
 *      K. M. Barry, D. A. Cavers and C. W. Kneale, "Special Report:
 *              Recommended Standards for Digital Tape Formats",
 *              Geophysics, vol. 40, no. 2 (April 1975), P. 344-352.
 *      
 * $Author: john $
 * $Source: /usr/local/cwp/src/su/include/RCS/segy.h,v $
 * $Revision: 1.33 $ ; $Date: 2011/11/11 23:56:14 $
 */ 

#include <limits.h>

#ifndef SEGY_H
#define SEGY_H

#define SU_NFLTS        65535   /*   Arbitrary limit on data array size */
/* #define SU_NFLTS     32767    Arbitrary limit on data array size     */


/* TYPEDEFS */
typedef struct {        /* segy - trace identification header */

        int tracl;      /* Trace sequence number within line
                           --numbers continue to increase if the
                           same line continues across multiple
                           SEG Y files.
                           byte# 1-4
                         */

        int tracr;      /* Trace sequence number within SEG Y file
                           ---each file starts with trace sequence
                           one
                           byte# 5-8
                         */

        int fldr;       /* Original field record number
                           byte# 9-12 
                        */

        int tracf;      /* Trace number within original field record 
                           byte# 13-16
                        */

        int ep;         /* energy source point number
                           ---Used when more than one record occurs
                           at the same effective surface location.
                           byte# 17-20
                         */

        int cdp;        /* Ensemble number (i.e. CDP, CMP, CRP,...) 
                           byte# 21-24
                        */

        int cdpt;       /* trace number within the ensemble
                           ---each ensemble starts with trace number one.
                           byte# 25-28
                         */

        short trid;     /* trace identification code:
                        -1 = Other
                         0 = Unknown
                         1 = Seismic data
                         2 = Dead
                         3 = Dummy
                         4 = Time break
                         5 = Uphole
                         6 = Sweep
                         7 = Timing
                         8 = Water break
                         9 = Near-field gun signature
                        10 = Far-field gun signature
                        11 = Seismic pressure sensor
                        12 = Multicomponent seismic sensor
                                - Vertical component
                        13 = Multicomponent seismic sensor
                                - Cross-line component 
                        14 = Multicomponent seismic sensor
                                - in-line component 
                        15 = Rotated multicomponent seismic sensor
                                - Vertical component
                        16 = Rotated multicomponent seismic sensor
                                - Transverse component
                        17 = Rotated multicomponent seismic sensor
                                - Radial component
                        18 = Vibrator reaction mass
                        19 = Vibrator baseplate
                        20 = Vibrator estimated ground force
                        21 = Vibrator reference
                        22 = Time-velocity pairs
                        23 ... N = optional use 
                                (maximum N = 32,767)

                        Following are CWP id flags:

                        109 = autocorrelation
                        110 = Fourier transformed - no packing
                             xr[0],xi[0], ..., xr[N-1],xi[N-1]
                        111 = Fourier transformed - unpacked Nyquist
                             xr[0],xi[0],...,xr[N/2],xi[N/2]
                        112 = Fourier transformed - packed Nyquist
                             even N:
                             xr[0],xr[N/2],xr[1],xi[1], ...,
                                xr[N/2 -1],xi[N/2 -1]
                                (note the exceptional second entry)
                             odd N:
                             xr[0],xr[(N-1)/2],xr[1],xi[1], ...,
                                xr[(N-1)/2 -1],xi[(N-1)/2 -1],xi[(N-1)/2]
                                (note the exceptional second & last entries)
                        113 = Complex signal in the time domain
                             xr[0],xi[0], ..., xr[N-1],xi[N-1]
                        114 = Fourier transformed - amplitude/phase
                             a[0],p[0], ..., a[N-1],p[N-1]
                        115 = Complex time signal - amplitude/phase
                             a[0],p[0], ..., a[N-1],p[N-1]
                        116 = Real part of complex trace from 0 to Nyquist
                        117 = Imag part of complex trace from 0 to Nyquist
                        118 = Amplitude of complex trace from 0 to Nyquist
                        119 = Phase of complex trace from 0 to Nyquist
                        121 = Wavenumber time domain (k-t)
                        122 = Wavenumber frequency (k-omega)
                        123 = Envelope of the complex time trace
                        124 = Phase of the complex time trace
                        125 = Frequency of the complex time trace
                        130 = Depth-Range (z-x) traces
                        201 = Seismic data packed to bytes (by supack1)
                        202 = Seismic data packed to 2 bytes (by supack2)
                           byte# 29-30
                        */

        short nvs;      /* Number of vertically summed traces yielding
                           this trace. (1 is one trace, 
                           2 is two summed traces, etc.)
                           byte# 31-32
                         */

        short nhs;      /* Number of horizontally summed traces yielding
                           this trace. (1 is one trace
                           2 is two summed traces, etc.)
                           byte# 33-34
                         */

        short duse;     /* Data use:
                                1 = Production
                                2 = Test
                           byte# 35-36
                         */

        int offset;     /* Distance from the center of the source point 
                           to the center of the receiver group 
                           (negative if opposite to direction in which 
                           the line was shot).
                           byte# 37-40
                         */

        int gelev;      /* Receiver group elevation from sea level
                           (all elevations above the Vertical datum are 
                           positive and below are negative).
                           byte# 41-44
                         */

        int selev;      /* Surface elevation at source.
                           byte# 45-48
                         */

        int sdepth;     /* Source depth below surface (a positive number).
                           byte# 49-52
                         */

        int gdel;       /* Datum elevation at receiver group.
                           byte# 53-56
                        */

        int sdel;       /* Datum elevation at source.
                           byte# 57-60
                        */

        int swdep;      /* Water depth at source.
                           byte# 61-64
                        */

        int gwdep;      /* Water depth at receiver group.
                           byte# 65-68
                        */

        short scalel;   /* Scalar to be applied to the previous 7 entries
                           to give the real value. 
                           Scalar = 1, +10, +100, +1000, +10000.
                           If positive, scalar is used as a multiplier,
                           if negative, scalar is used as a divisor.
                           byte# 69-70
                         */

        short scalco;   /* Scalar to be applied to the next 4 entries
                           to give the real value. 
                           Scalar = 1, +10, +100, +1000, +10000.
                           If positive, scalar is used as a multiplier,
                           if negative, scalar is used as a divisor.
                           byte# 71-72
                         */

        int  sx;        /* Source coordinate - X 
                           byte# 73-76
                        */

        int  sy;        /* Source coordinate - Y 
                           byte# 77-80
                        */

        int  gx;        /* Group coordinate - X 
                           byte# 81-84
                        */

        int  gy;        /* Group coordinate - Y 
                           byte# 85-88
                        */

        short counit;   /* Coordinate units: (for previous 4 entries and
                                for the 7 entries before scalel)
                           1 = Length (meters or feet)
                           2 = Seconds of arc
                           3 = Decimal degrees
                           4 = Degrees, minutes, seconds (DMS)

                        In case 2, the X values are longitude and 
                        the Y values are latitude, a positive value designates
                        the number of seconds east of Greenwich
                                or north of the equator

                        In case 4, to encode +-DDDMMSS
                        counit = +-DDD*10^4 + MM*10^2 + SS,
                        with scalco = 1. To encode +-DDDMMSS.ss
                        counit = +-DDD*10^6 + MM*10^4 + SS*10^2 
                        with scalco = -100.
                           byte# 89-90
                        */

        short wevel;    /* Weathering velocity. 
                           byte# 91-92
                        */

        short swevel;   /* Subweathering velocity. 
                           byte# 93-94
                        */

        short sut;      /* Uphole time at source in milliseconds. 
                           byte# 95-96
                        */

        short gut;      /* Uphole time at receiver group in milliseconds. 
                           byte# 97-98
                        */

        short sstat;    /* Source static correction in milliseconds. 
                           byte# 99-100
                        */

        short gstat;    /* Group static correction  in milliseconds.
                           byte# 101-102
                        */

        short tstat;    /* Total static applied  in milliseconds.
                           (Zero if no static has been applied.)
                           byte# 103-104
                        */

        short laga;     /* Lag time A, time in ms between end of 240-
                           byte trace identification header and time
                           break, positive if time break occurs after
                           end of header, time break is defined as
                           the initiation pulse which maybe recorded
                           on an auxiliary trace or as otherwise
                           specified by the recording system 
                           byte# 105-106
                        */

        short lagb;     /* lag time B, time in ms between the time break
                           and the initiation time of the energy source,
                           may be positive or negative 
                           byte# 107-108
                        */

        short delrt;    /* delay recording time, time in ms between
                           initiation time of energy source and time
                           when recording of data samples begins
                           (for deep water work if recording does not
                           start at zero time) 
                           byte# 109-110
                        */

        short muts;     /* mute time--start 
                           byte# 111-112
                        */

        short mute;     /* mute time--end 
                           byte# 113-114
                        */

        unsigned short ns;      /* number of samples in this trace 
                           byte# 115-116
                        */

        unsigned short dt;      /* sample interval; in micro-seconds
                           byte# 117-118
                        */

        short gain;     /* gain type of field instruments code:
                                1 = fixed
                                2 = binary
                                3 = floating point
                                4 ---- N = optional use 
                           byte# 119-120
                        */

        short igc;      /* instrument gain constant 
                           byte# 121-122
                        */

        short igi;      /* instrument early or initial gain 
                           byte# 123-124
                        */

        short corr;     /* correlated:
                                1 = no
                                2 = yes 
                           byte# 125-126
                        */

        short sfs;      /* sweep frequency at start 
                           byte# 127-128
                        */

        short sfe;      /* sweep frequency at end
                           byte# 129-130
                        */

        short slen;     /* sweep length in ms 
                           byte# 131-132
                        */

        short styp;     /* sweep type code:
                                1 = linear
                                2 = cos-squared
                                3 = other
                           byte# 133-134
                        */

        short stas;     /* sweep trace length at start in ms
                           byte# 135-136
                        */

        short stae;     /* sweep trace length at end in ms 
                           byte# 137-138
                        */

        short tatyp;    /* taper type: 1=linear, 2=cos^2, 3=other 
                           byte# 139-140
                        */

        short afilf;    /* alias filter frequency if used 
                           byte# 141-142
                        */

        short afils;    /* alias filter slope
                           byte# 143-144
                        */

        short nofilf;   /* notch filter frequency if used
                           byte# 145-146
                        */

        short nofils;   /* notch filter slope
                           byte# 147-148
                        */

        short lcf;      /* low cut frequency if used
                           byte# 149-150
                        */

        short hcf;      /* high cut frequncy if used
                           byte# 151-152
                        */

        short lcs;      /* low cut slope
                           byte# 153-154
                        */

        short hcs;      /* high cut slope
                           byte# 155-156
                        */

        short year;     /* year data recorded
                           byte# 157-158
                        */

        short day;      /* day of year
                           byte# 159-160
                        */

        short hour;     /* hour of day (24 hour clock) 
                           byte# 161-162
                        */

        short minute;   /* minute of hour
                           byte# 163-164
                        */

        short sec;      /* second of minute
                           byte# 165-166
                        */

        short timbas;   /* time basis code:
                                1 = local
                                2 = GMT
                                3 = other
                           byte# 167-168
                        */

        short trwf;     /* trace weighting factor, defined as 1/2^N
                           volts for the least sigificant bit
                           byte# 169-170
                        */

        short grnors;   /* geophone group number of roll switch
                           position one
                           byte# 171-172
                        */

        short grnofr;   /* geophone group number of trace one within
                           original field record
                           byte# 173-174
                        */

        short grnlof;   /* geophone group number of last trace within
                           original field record
                           byte# 175-176
                        */

        short gaps;     /* gap size (total number of groups dropped)
                           byte# 177-178
                        */

        short otrav;    /* overtravel taper code:
                                1 = down (or behind)
                                2 = up (or ahead)
                           byte# 179-180
                        */

#ifdef SLTSU_SEGY_H  /* begin Unocal SU segy.h differences */


        /* cwp local assignments */
        float d1;       /* sample spacing for non-seismic data
                           byte# 181-184
                        */

        float f1;       /* first sample location for non-seismic data
                           byte# 185-188
                        */

        float d2;       /* sample spacing between traces
                           byte# 189-192
                        */

        float f2;       /* first trace location
                           byte# 193-196
                        */

        float ungpow;   /* negative of power used for dynamic
                           range compression
                           byte# 197-200
                        */

        float unscale;  /* reciprocal of scaling factor to normalize
                           range
                           byte# 201-204
                        */

        short mark;     /* mark selected traces
                           byte# 205-206
                        */

        /* SLTSU local assignments */ 
        short mutb;     /* mute time at bottom (start time)
                           bottom mute ends at last sample
                           byte# 207-208
                        */
        float dz;       /* depth sampling interval in (m or ft)
                        if =0.0, input are time samples
                           byte# 209-212
                        */

        float fz;       /* depth of first sample in (m or ft)
                           byte# 213-116
                        */

        short n2;       /* number of traces per cdp or per shot
                           byte# 217-218
                        */

        short shortpad; /* alignment padding
                           byte# 219-220
                        */

        int ntr;        /* number of traces
                           byte# 221-224
                        */

        /* SLTSU local assignments end */ 

        short unass[8]; /* unassigned
                           byte# 225-240
                        */

#else

        /* cwp local assignments */
        float d1;       /* sample spacing for non-seismic data
                           byte# 181-184
                        */

        float f1;       /* first sample location for non-seismic data
                           byte# 185-188
                        */

        float d2;       /* sample spacing between traces
                           byte# 189-192
                        */

        float f2;       /* first trace location
                           byte# 193-196
                        */

        float ungpow;   /* negative of power used for dynamic
                           range compression
                           byte# 197-200
                        */

        float unscale;  /* reciprocal of scaling factor to normalize
                           range
                           byte# 201-204
                        */

        int ntr;        /* number of traces
                           byte# 205-208
                        */

        short mark;     /* mark selected traces
                           byte# 209-210
                        */

        short shortpad; /* alignment padding
                           byte# 211-212
                        */


        short unass[14];        /* unassigned--NOTE: last entry causes 
                           a break in the word alignment, if we REALLY
                           want to maintain 240 bytes, the following
                           entry should be an odd number of short/UINT2
                           OR do the insertion above the "mark" keyword
                           entry
                           byte# 213-240
                        */
#endif

        float  data[SU_NFLTS];

} segy;


typedef struct {        /* bhed - binary header */

        int jobid;      /* job identification number */

        int lino;       /* line number (only one line per reel) */

        int reno;       /* reel number */

        short ntrpr;    /* number of data traces per record */

        short nart;     /* number of auxiliary traces per record */

        unsigned short hdt; /* sample interval in micro secs for this reel */

        unsigned short dto; /* same for original field recording */

        unsigned short hns; /* number of samples per trace for this reel */

        unsigned short nso; /* same for original field recording */

        short format;   /* data sample format code:
                                1 = floating point, 4 byte (32 bits)
                                2 = fixed point, 4 byte (32 bits)
                                3 = fixed point, 2 byte (16 bits)
                                4 = fixed point w/gain code, 4 byte (32 bits)
                                5 = IEEE floating point, 4 byte (32 bits)
                                8 = two's complement integer, 1 byte (8 bits)
                        */

        short fold;     /* CDP fold expected per CDP ensemble */

        short tsort;    /* trace sorting code: 
                                1 = as recorded (no sorting)
                                2 = CDP ensemble
                                3 = single fold continuous profile
                                4 = horizontally stacked */

        short vscode;   /* vertical sum code:
                                1 = no sum
                                2 = two sum ...
                                N = N sum (N = 32,767) */

        short hsfs;     /* sweep frequency at start */

        short hsfe;     /* sweep frequency at end */

        short hslen;    /* sweep length (ms) */

        short hstyp;    /* sweep type code:
                                1 = linear
                                2 = parabolic
                                3 = exponential
                                4 = other */

        short schn;     /* trace number of sweep channel */

        short hstas;    /* sweep trace taper length at start if
                           tapered (the taper starts at zero time
                           and is effective for this length) */

        short hstae;    /* sweep trace taper length at end (the ending
                           taper starts at sweep length minus the taper
                           length at end) */

        short htatyp;   /* sweep trace taper type code:
                                1 = linear
                                2 = cos-squared
                                3 = other */

        short hcorr;    /* correlated data traces code:
                                1 = no
                                2 = yes */

        short bgrcv;    /* binary gain recovered code:
                                1 = yes
                                2 = no */

        short rcvm;     /* amplitude recovery method code:
                                1 = none
                                2 = spherical divergence
                                3 = AGC
                                4 = other */

        short mfeet;    /* measurement system code:
                                1 = meters
                                2 = feet */

        short polyt;    /* impulse signal polarity code:
                                1 = increase in pressure or upward
                                    geophone case movement gives
                                    negative number on tape
                                2 = increase in pressure or upward
                                    geophone case movement gives
                                    positive number on tape */

        short vpol;     /* vibratory polarity code:
                                code    seismic signal lags pilot by
                                1       337.5 to  22.5 degrees
                                2        22.5 to  67.5 degrees
                                3        67.5 to 112.5 degrees
                                4       112.5 to 157.5 degrees
                                5       157.5 to 202.5 degrees
                                6       202.5 to 247.5 degrees
                                7       247.5 to 292.5 degrees
                                8       293.5 to 337.5 degrees */

        short hunass[170];      /* unassigned */

} bhed;

/* DEFINES */
#define gettr(x)        fgettr(stdin, (x))
#define vgettr(x)       fvgettr(stdin, (x))
#define puttr(x)        fputtr(stdout, (x))
#define vputtr(x)       fvputtr(stdout, (x))
#define gettra(x, y)    fgettra(stdin, (x), (y))


/* TOTHER represents "other"                                    */
#define         TOTHER          -1      
/* TUNK represents time traces of an unknown type               */
#define         TUNK            0
/* TREAL represents real time traces                            */
#define         TREAL           1
/* TDEAD represents dead time traces                            */
#define         TDEAD           2
/* TDUMMY represents dummy time traces                          */
#define         TDUMMY          3
/* TBREAK represents time break traces                          */
#define         TBREAK          4
/* UPHOLE represents uphole traces                              */
#define         UPHOLE          5
/* SWEEP represents sweep traces                                */
#define         SWEEP           6
/* TIMING represents timing traces                              */
#define         TIMING          7
/* WBREAK represents timing traces                              */
#define         WBREAK          8
/* NFGUNSIG represents near field gun signature                 */
#define         NFGUNSIG        9       
/* FFGUNSIG represents far field gun signature                  */
#define         FFGUNSIG        10
/* SPSENSOR represents seismic pressure sensor                  */
#define         SPSENSOR        11
/* TVERT represents multicomponent seismic sensor 
        - vertical component */
#define         TVERT           12
/* TXLIN represents multicomponent seismic sensor 
        - cross-line component */
#define         TXLIN           13
/* TINLIN represents multicomponent seismic sensor 
        - in-line component */
#define         TINLIN  14
/* ROTVERT represents rotated multicomponent seismic sensor 
        - vertical component */
#define         ROTVERT         15
/* TTRANS represents rotated multicomponent seismic sensor 
        - transverse component */
#define         TTRANS          16
/* TRADIAL represents rotated multicomponent seismic sensor 
        - radial component */
#define         TRADIAL         17
/* VRMASS represents vibrator reaction mass */
#define         VRMASS          18
/* VBASS represents vibrator baseplate */
#define         VBASS           19
/* VEGF represents vibrator estimated ground force */
#define         VEGF            20
/* VREF represents vibrator reference */
#define         VREF            21

/*** CWP trid assignments ***/
/* ACOR represents autocorrelation  */
#define         ACOR            109
/* FCMPLX represents fourier transformed - no packing 
   xr[0],xi[0], ..., xr[N-1],xi[N-1] */
#define         FCMPLX          110
/* FUNPACKNYQ represents fourier transformed - unpacked Nyquist
   xr[0],xi[0],...,xr[N/2],xi[N/2] */
#define         FUNPACKNYQ      111
/* FTPACK represents fourier transformed - packed Nyquist
   even N: xr[0],xr[N/2],xr[1],xi[1], ...,
        xr[N/2 -1],xi[N/2 -1]
   (note the exceptional second entry)
    odd N:
     xr[0],xr[(N-1)/2],xr[1],xi[1], ...,
     xr[(N-1)/2 -1],xi[(N-1)/2 -1],xi[(N-1)/2]
   (note the exceptional second & last entries)
*/
#define         FTPACK          112
/* TCMPLX represents complex time traces                        */
#define         TCMPLX          113
/* FAMPH represents freq domain data in amplitude/phase form    */
#define         FAMPH           114
/* TAMPH represents time domain data in amplitude/phase form    */
#define         TAMPH           115
/* REALPART represents the real part of a trace to Nyquist      */
#define         REALPART        116
/* IMAGPART represents the real part of a trace to Nyquist      */
#define         IMAGPART        117
/* AMPLITUDE represents the amplitude of a trace to Nyquist     */
#define         AMPLITUDE       118
/* PHASE represents the phase of a trace to Nyquist             */
#define         PHASE           119
/* KT represents wavenumber-time domain data                    */
#define         KT              121
/* KOMEGA represents wavenumber-frequency domain data           */
#define         KOMEGA          122
/* ENVELOPE represents the envelope of the complex time trace   */
#define         ENVELOPE        123
/* INSTPHASE represents the phase of the complex time trace     */
#define         INSTPHASE       124
/* INSTFREQ represents the frequency of the complex time trace  */
#define         INSTFREQ        125
/* DEPTH represents traces in depth-range (z-x)                 */
#define         TRID_DEPTH      130
/* 3C data...  v,h1,h2=(11,12,13)+32 so a bitmask will convert  */
/* between conventions */
/* CHARPACK represents byte packed seismic data from supack1    */
#define         CHARPACK        201
/* SHORTPACK represents 2 byte packed seismic data from supack2 */
#define         SHORTPACK       202


#define ISSEISMIC(id) (( (id)==TUNK || (id)==TREAL || (id)==TDEAD || (id)==TDUMMY || (id)==TBREAK || (id)==UPHOLE || (id)==SWEEP || (id)==TIMING || (id)==WBREAK || (id)==NFGUNSIG || (id)==FFGUNSIG || (id)==SPSENSOR || (id)==TVERT || (id)==TXLIN || (id)==TINLIN || (id)==ROTVERT || (id)==TTRANS || (id)==TRADIAL || (id)==ACOR ) ? cwp_true : cwp_false ) 

/* FUNCTION PROTOTYPES */
#ifdef __cplusplus /* if C++, specify external linkage to C functions */
extern "C" {
#endif

/* get trace and put trace */
int fgettr(FILE *fp, segy *tp);
int fvgettr(FILE *fp, segy *tp);
void fputtr(FILE *fp, segy *tp);
void fvputtr(FILE *fp, segy *tp);
int fgettra(FILE *fp, segy *tp, int itr);

/* get gather and put gather */
/*segy **fget_gather(FILE *fp, cwp_String *key,cwp_String *type,Value *n_val,
                        int *nt,int *ntr, float *dt,int *first);
segy **get_gather(cwp_String *key, cwp_String *type, Value *n_val,
                        int *nt, int *ntr, float *dt, int *first);
segy **fput_gather(FILE *fp, segy **rec,int *nt, int *ntr);
segy **put_gather(segy **rec,int *nt, int *ntr);*/

/* hdrpkge */
/*void gethval(const segy *tp, int index, Value *valp);
void puthval(segy *tp, int index, Value *valp);
void getbhval(const bhed *bhp, int index, Value *valp);
void putbhval(bhed *bhp, int index, Value *valp);
void gethdval(const segy *tp, char *key, Value *valp);
void puthdval(segy *tp, char *key, Value *valp);
char *hdtype(const char *key);
char *getkey(const int index);
int getindex(const char *key);
void swaphval(segy *tp, int index);
void swapbhval(bhed *bhp, int index);
void printheader(const segy *tp);*/

void tabplot(segy *tp, int itmin, int itmax);

#ifdef __cplusplus /* if C++, end external linkage specification */
}
#endif

#endif