SoVRSegyTraceIdHeader Struct Reference
[Readers]

VolumeViz SEGY trace identification header. More...

#include <VolumeViz/readers/SoVRSegyReader.h>

List of all members.

Public Attributes

int tracl
int tracr
int fldr
int tracf
int ep
int cdp
int cdpt
short trid
short nvs
short nhs
short duse
int offset
int gelev
int selev
int sdepth
int gdel
int sdel
int swdep
int gwdep
short scalel
short scalco
int sx
int sy
int gx
int gy
short counit
short wevel
short swevel
short sut
short gut
short sstat
short gstat
short tstat
short laga
short lagb
short delrt
short muts
short mute
unsigned short ns
unsigned short dt
short gain
short igc
short igi
short corr
short sfs
short sfe
short slen
short styp
short stas
short stae
short tatyp
short afilf
short afils
short nofilf
short nofils
short lcf
short hcf
short lcs
short hcs
short year
short day
short hour
short minute
short sec
short timbas
short trwf
short grnors
short grnofr
short grnlof
short gaps
short otrav
int cdpX
int cdpY
int inlineNumber
int crosslineNumber
int shotPointNumber
short shotPointScale
short tvmu
int transductionConstantM
short transductionConstantP
short transductionUnits
short dtid
short tscale
short unass [12]

Detailed Description

VolumeViz SEGY trace identification header.

This class encapsulates the contents of a SEGY trace header (SEGY is a widely used format for storing seismic data). It is used to query this information from the SEGY file reader (see SoVRSegyFileReader::getSegyTraceHeader). See also SoVRSegyFileHeader.


Member Data Documentation

Alias filter frequency if used.

Alias filter slope.

CDP ensemble number.

Trace number within CDP ensemble.

X coordinate of ensemble (CDP) position of this trace.

Y coordinate of ensemble (CDP) position of this trace.

Correlated:
1 = No
2 = Yes.

Coordinate units code:
For previous four entries
1 = Length (meters or feet)
2 = Seconds of arc (In this case, 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.)
3 = Decimal degrees
4 = Degrees, minutes, seconds

Cross-line number, for 3D poststack data.

Day of year.

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).

unsigned short SoVRSegyTraceIdHeader::dt

Sample interval; in micro-seconds.

Device/Trace Identifier.

Data use:
1 = Production
2 = Test.

Energy source point number.

Field record number.

Gain type of field instruments code:
1 = Fixed
2 = Binary
3 = Floating point
4...N = optional use.

Gap size (total number of groups dropped).

Datum elevation at receiver group.

Receiver group elevation from sea level (above sea level is positive).

Geophone group number of last trace within original field record.

Geophone group number of trace one within original field record.

Geophone group number of roll switch position one.

Group static correction.

Uphole time at receiver group.

Water depth at receiver group.

X group coordinate.

Y group coordinate.

High cut frequncy if used.

High cut slope.

Hour of day (24 hour clock).

Instrument gain constant.

Instrument early or initial gain.

Inline-line number, for 3D poststack data.

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

Lag time B, time in ms between the time break and the initiation time of the energy source.

May be positive or negative

Low cut frequency if used.

Low cut slope.

Minute of hour.

Mute time--end.

Mute time--start.

Number of horizontally summed traces (see SoVRSegyFileHeader::SoVRSegyFileHeader).

Notch filter frequency if used.

Notch filter slope.

unsigned short SoVRSegyTraceIdHeader::ns

Number of samples in this trace.

Number of vertically summed traces (see SoVRSegyFileHeader::vscode).

Distance from source point to receiver group (negative if opposite to direction in which the line was shot).

Overtravel taper code:
1 = Down (or behind)
2 = Up (or ahead).

Scale factor for next 4 entries with value plus or minus 10 to the power 0, 1, 2, 3, or 4 (if positive, multiply, if negative divide).

Scale factor for previous 7 entries with value plus or minus 10 to the power 0, 1, 2, 3, or 4 (if positive, multiply, if negative divide).

Datum elevation at source.

Source depth (positive).

Second of minute.

Source elevation from sea level (above sea level is positive).

Sweep frequency at end.

Sweep frequency at start.

Shotpoint number, for 2D poststack data.

Scalar to be applied to shotPointNumber to give the real value.

Sweep length in ms.

Source static correction.

Sweep trace length at end in ms.

Sweep trace length at start in ms.

Sweep type code:
1 = Linear
2 = Cos-squared
3 = Other.

Uphole time at source.

Water depth at source.

Subweathering velocity.

X source coordinate.

Y source coordinate.

Taper type:
1=linear,
2=cos^2,
3=other.

Time basis code:
1 = Local
2 = GMT
3 = Other
4 = UTC.

Trace number within field record.

Trace sequence number within line.

Trace sequence number within reel.

Transduction Constant Mantissa.

Transduction Constant Power of ten.

Transduction Units 0 = Unknown 1 = Pascal (Pa) 2 = Volts (v) 3 = Millivolts (mV) 4 = Amperes (A) 5 = Meters (m) 6 = Meters per second (m/s) 7 = Meters per second squared (m/s2) 8 = Newton (N) 9 = Watt (W).

Trace identification code:
1 = Seismic data
2 = Dead
3 = Dummy
4 = Time break
5 = Uphole
6 = Sweep
7 = Timing
8 = Water break
9...N = optional use (N = 32,767).

Following are CWP id flags:

9 = Autocorrelation

10 = Fourier transformed - no packing
xr[0],xi[0], ..., xr[N-1],xi[N-1]

11 = Fourier transformed - unpacked Nyquist
xr[0],xi[0],...,xr[N/2],xi[N/2]

12 = 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)

13 = Complex signal in the time domain
xr[0],xi[0], ..., xr[N-1],xi[N-1]

14 = Fourier transformed - amplitude/phase
a[0],p[0], ..., a[N-1],p[N-1]

15 = Complex time signal - amplitude/phase
a[0],p[0], ..., a[N-1],p[N-1]

16 = Real part of complex trace from 0 to Nyquist
17 = Imag part of complex trace from 0 to Nyquist
18 = Amplitude of complex trace from 0 to Nyquist
19 = Phase of complex trace from 0 to Nyquist
21 = Wavenumber time domain (k-t)
22 = Wavenumber frequency (k-omega)
23 = Envelope of the complex time trace
24 = Phase of the complex time trace
25 = Frequency of the complex time trace
30 = Depth-Range (z-x) traces
43 = Seismic Data, Vertical Component
44 = Seismic Data, Horizontal Component 1
45 = Seismic Data, Horizontal Component 2
46 = Seismic Data, Radial Component
47 = Seismic Data, Transverse Component
101 = Seismic data packed to bytes (by supack1)
102 = Seismic data packed to 2 bytes (by supack2)

Trace weighting factor, defined as 1/2^N volts for the least sigificant bit.

Scalar to be applied to - sut, gut, sstat, gstat, tstat, laga, lagb, delrt, muts, mute - header info to get the true time value in milliseconds.

Total static applied.

Trace value measurement unit 0 = Unknown 1 = Pascal (Pa) 2 = Volts (v) 3 = Millivolts (mV) 4 = Amperes (A) 5 = Meters (m) 6 = Meters per second (m/s) 7 = Meters per second squared (m/s2) 8 = Newton (N) 9 = Watt (W).

Unassigned.

Weathering velocity.

Year data recorded.


The documentation for this struct was generated from the following file:

Open Inventor Toolkit reference manual, generated on 12 Sep 2022
Copyright © Thermo Fisher Scientific All rights reserved.
http://www.openinventor.com/