Editing Documentation:system/seismic (section)

==sfsegyread==
{| class="wikitable" align="center" cellspacing="0" border="1"
! colspan="4" style="background:#ffdead;" | Convert a SEG-Y or SU dataset to RSF.
|-
! colspan="4" | sfsegyread mask=msk.rsf > out.rsf tfile=hdr.rsf verb=n su= suxdr=n endian=y n2=0 format=segyformat (bhead) ns=segyns (bhead) key#= tape= hfile= bfile= read=
|-
|  colspan="4" | <br>Data headers and trace headers are separated from the data.<br><br>"suread" is equivalent to "segyread su=y"<br><br>SEGY key names:<br><br>tracl: trace sequence number within line 0<br><br>tracr: trace sequence number within reel 4<br><br>fldr:     field record number 8 <br><br>tracf:    trace number within field record 12 <br><br>ep:       energy source point number 16 <br><br>cdp:      CDP ensemble number 20 <br><br>cdpt:     trace number within CDP ensemble 24 <br><br>trid:     trace identification code:<br>1 = seismic data<br>2 = dead<br>3 = dummy<br>4 = time break<br>5 = uphole<br>6 = sweep<br>7 = timing<br>8 = water break<br>9---, N = optional use (N = 32,767) 28 <br><br>nvs:      number of vertically summed traces 30 <br><br>nhs:      number of horizontally summed traces 32 <br><br>duse:     data use:<br>1 = production<br>2 = test 34<br><br>offset:   distance from source point to receiver<br>group (negative if opposite to direction<br>in which the line was shot) 36 <br><br>gelev:    receiver group elevation from sea level<br>(above sea level is positive) 40 <br><br>selev:    source elevation from sea level<br>(above sea level is positive) 44 <br><br>sdepth:   source depth (positive) 48 <br><br>gdel:     datum elevation at receiver group 52 <br><br>sdel:     datum elevation at source 56 <br><br>swdep:    water depth at source 60 <br><br>gwdep:    water depth at receiver group 64 <br><br>scalel:   scale factor for previous 7 entries<br>with value plus or minus 10 to the<br>power 0, 1, 2, 3, or 4 (if positive,<br>multiply, if negative divide) 68 <br><br>scalco:   scale factor for next 4 entries<br>with value plus or minus 10 to the<br>power 0, 1, 2, 3, or 4 (if positive,<br>multiply, if negative divide) 70 <br><br>sx:       X source coordinate 72 <br><br>sy:       Y source coordinate 76 <br><br>gx:       X group coordinate 80 <br><br>gy:       Y group coordinate 84 <br><br>counit:   coordinate units code:<br>for previous four entries<br>1 = length (meters or feet)<br>2 = seconds of arc (in this case, the<br>X values are unsigned longitude and the Y values<br>are latitude, a positive value designates<br>the number of seconds east of Greenwich<br>or north of the equator 88 <br><br>wevel:     weathering velocity 90 <br><br>swevel:    subweathering velocity 92 <br><br>sut:       uphole time at source 94 <br><br>gut:       uphole time at receiver group 96 <br><br>sstat:     source static correction 98 <br><br>gstat:     group static correction 100 <br><br>tstat:     total static applied 102 <br><br>laga:      lag time A, time in ms between end of 240-<br>byte trace identification header and time<br>break, positive if time break occurs after<br>end of header, time break is defined as<br>the initiation pulse which maybe recorded<br>on an auxiliary trace or as otherwise<br>specified by the recording system 104 <br><br>lagb:      lag time B, time in ms between the time<br>break and the initiation time of the energy source,<br>may be positive or negative 106 <br><br>delrt:     delay recording time, time in ms between<br>initiation time of energy source and time<br>when recording of data samples begins<br>(for deep water work if recording does not<br>start at zero time) 108 <br><br>muts:      mute time--start 110 <br><br>mute:      mute time--end 112 <br><br>ns:        number of samples in this trace 114 <br><br>dt:        sample interval, in micro-seconds 116 <br><br>gain:      gain type of field instruments code:<br>1 = fixed<br>2 = binary<br>3 = floating point<br>4 ---- N = optional use 118 <br><br>igc:       instrument gain constant 120 <br><br>igi:       instrument early or initial gain 122 <br><br>corr:      correlated:<br>1 = no<br>2 = yes 124<br><br>sfs:       sweep frequency at start 126 <br><br>sfe:       sweep frequency at end 128 <br><br>slen:      sweep length in ms 130 <br><br>styp:      sweep type code:<br>1 = linear<br>2 = cos-squared<br>3 = other 132<br><br>stas:      sweep trace length at start in ms 134 <br><br>stae:      sweep trace length at end in ms 136 <br><br>tatyp:     taper type: 1=linear, 2=cos^2, 3=other 138 <br><br>afilf:     alias filter frequency if used 140 <br><br>afils:     alias filter slope 142 <br><br>nofilf:    notch filter frequency if used 144 <br><br>nofils:    notch filter slope 146 <br><br>lcf:       low cut frequency if used 148 <br><br>hcf:       high cut frequncy if used 150 <br><br>lcs:       low cut slope 152 <br><br>hcs:       high cut slope 154 <br><br>year:      year data recorded 156 <br><br>day:       day of year 158 <br><br>hour:      hour of day (24 hour clock) 160 <br><br>minute:    minute of hour 162 <br><br>sec:       second of minute 164 <br><br>timbas:    time basis code:<br>1 = local<br>2 = GMT<br>3 = other 166<br><br>trwf:      trace weighting factor, defined as 1/2^N<br>volts for the least sigificant bit 168 <br><br>grnors:    geophone group number of roll switch<br>position one 170<br><br>grnofr:    geophone group number of trace one within<br>original field record 172<br><br>grnlof:    geophone group number of last trace within<br>original field record 174<br><br>gaps:      gap size (total number of groups dropped) 176 <br><br>otrav:     overtravel taper code: <br>1 = down (or behind)<br>2 = up (or ahead) 178<br><br>cdpx:   X coordinate of CDP 180<br><br>cdpy:   Y coordinate of CDP 184<br><br>iline:  in-line number 188 <br><br>xline:  cross-line number 192<br><br>shnum:  shotpoint number 196<br><br>shsca:  shotpoint scalar 200<br><br>tval:   trace value meas. 202<br><br>tconst4: transduction const 204<br><br>tconst2: transduction const 208<br><br>tunits:  transduction units 210<br><br>device:  device identifier 212<br><br>tscalar: time scalar 214<br><br>stype:   source type 216<br><br>sendir:  source energy dir. 218<br> <br>unknown: unknown 222<br><br>smeas4:  source measurement 224<br><br>smeas2:  source measurement 228<br><br>smeasu:  source measurement unit 230 <br><br>unass1:  unassigned 232<br><br>unass2:  unassigned 236
|-
| ''string '' || '''bfile=''' ||   || 	output binary data header file
|-
| ''bool   '' || '''endian=y''' ||  [y/n] || 	Whether to automatically estimate endianness or not
|-
| ''int    '' || '''format=segyformat (bhead)''' ||  [1,2,3,5] || 	Data format. The default is taken from binary header.
:1 is IBM floating point
:2 is 4-byte integer
:3 is 2-byte integer
:5 is IEEE floating point
|-
| ''string '' || '''hfile=''' ||   || 	output text data header file
|-
| ''string '' || '''key#=''' ||   || 	extra key for trace headers
|-
| ''string '' || '''mask=''' ||   || 	optional header mask for reading only selected traces (auxiliary input file name)
|-
| ''int    '' || '''n2=0''' ||   || 	number of traces to read (if 0, read all traces)
|-
| ''int    '' || '''ns=segyns (bhead)''' ||   || 	Number of samples. The default is taken from binary header
|-
| ''string '' || '''read=''' ||   || 	what to read: h - header, d - data, b - both (default)
|-
| ''bool   '' || '''su=''' ||  [y/n] || 	y if input is SU, n if input is SEGY
|-
| ''bool   '' || '''suxdr=n''' ||  [y/n] || 	y, SU has XDR support
|-
| ''string '' || '''tape=''' ||   || 	input data
|-
| ''string '' || '''tfile=''' ||   || 	output trace header file (auxiliary output file name)
|-
| ''bool   '' || '''verb=n''' ||  [y/n] || 	Verbosity flag
|}