public final class SegyFileHeader extends Object
From the documentation:
The 400-byte Binary File Header record contains binary values that affect the whole SEG Y file. The values in the Binary File Header are defined as two-byte or four-byte, two's complement or unsigned integers, with the exception of optional IEEE double precision sample intervals. Certain values in this header are crucial for the processing of the data in the file, particularly the sample interval, trace length and format code. Revision 2.0 defines a few additional fields in the optional portion, as well as providing some clarification on the use of some existing entries.
Modifier and Type | Class and Description |
---|---|
static class |
SegyFileHeader.AmplitudeRecoveryType |
static class |
SegyFileHeader.DataFormat
Enumeration of the possible trace value data formats.
|
static class |
SegyFileHeader.ImpulseSignalPolarity |
static class |
SegyFileHeader.LengthUnit |
static class |
SegyFileHeader.Sorting |
static class |
SegyFileHeader.SweepTaperType |
static class |
SegyFileHeader.SweepType |
static class |
SegyFileHeader.VibratoryPolarity |
Modifier and Type | Method and Description |
---|---|
SegyFileHeader.AmplitudeRecoveryType |
getAmplitudeRecoveryType()
Return the amplitude recovery method of the SEG Y file.
|
int |
getCmpFold()
Return the ensamble fold of the SEG Y file.
|
SegyFileHeader.DataFormat |
getDataFormat()
Return the data format of the SEG Y file.
|
SegyFileHeader.ImpulseSignalPolarity |
getImpulseSignalPolarity()
Return the impulse signal polarity of the SEG Y file.
|
int |
getJobNo()
Return the job identification number of the SEG Y file.
|
SegyFileHeader.LengthUnit |
getLengthUnit()
Return the length unit of the SEG Y file.
|
int |
getLineNo()
Return the line number of the SEG Y file.
|
int |
getMaxCmpFold()
Return the max CMP fold of the SEG Y file.
|
int |
getNAuxillaryTraces()
Return the number of auxilliary traces per ensamble of the SEG Y file.
|
int |
getNExtendedRecords()
Return the number of 3200-byte extended records of the SEG Y file.
|
int |
getNSamples()
Return the number of samples per data trace of the SEG Y file.
|
int |
getNSamplesOriginal()
Return the number of samples per data trace for original field recording
of the SEG Y file.
|
int |
getNTracesPerShot()
Return the number of traces per ensamble of the SEG Y file.
|
int |
getReelNo()
Return the reel number of the SEG Y file.
|
int |
getSampleRate()
Return the sample interval of the SEG Y file.
|
int |
getSampleRateOriginal()
Return sample interval of original field recording of the SEG Y file.
|
SegyVersion |
getSegyVersion()
Return the SEG Y format revision number of the SEG Y file.
|
SegyFileHeader.Sorting |
getSorting()
Return the trace sorting of the SEG Y file.
|
int |
getSweepChannelNo()
Return the trace number of sweep channel of the SEG Y file.
|
int |
getSweepFrequencyAtEnd()
Return the sweep frequency at end of the SEG Y file.
|
int |
getSweepFrequencyAtStart()
Return the sweep frequency at start of the SEG Y file.
|
int |
getSweepLength()
Return the sweep length of the SEG Y file.
|
int |
getSweepTaperLengthAtEnd()
Return the sweep taper length at end of the SEG Y file.
|
int |
getSweepTaperLengthAtStart()
Return the sweep taper length at start of the SEG Y file.
|
SegyFileHeader.SweepTaperType |
getSweepTaperType()
Return the sweep taper type of the SEG Y file.
|
SegyFileHeader.SweepType |
getSweepType()
Return the sweep type of the SEG Y file.
|
int |
getVerticalSum()
Return the vertical sum code of the SEG Y file.
|
SegyFileHeader.VibratoryPolarity |
getVibratoryPolarity()
Return the vibratory polarity sector of the SEG Y file.
|
boolean |
isBinaryGainRecovery()
Return if binary gain has been recovered in the SEG Y file.
|
boolean |
isTraceFixedLength()
Return if the traces are fixed length in the SEG Y file.
|
boolean |
isTracesCorrelated()
Return the of the SEG Y file.
|
String |
toString() |
public int getJobNo()
public int getLineNo()
For 3-D poststack data, this will typically contain the in-line number.
public int getReelNo()
public int getNTracesPerShot()
Mandatory for prestack data.
public int getNAuxillaryTraces()
Mandatory for prestack data.
public int getSampleRate()
Sample interval. Microseconds (us) for time data, Hertz (Hz) for frequency data, meters (m) or feet (ft) for depth data.
public int getSampleRateOriginal()
public int getNSamples()
Note: The sample interval and number of samples in the Binary File Header should be for the primary set of seismic data traces in the file.
public int getNSamplesOriginal()
public SegyFileHeader.DataFormat getDataFormat()
Mandatory for all data.
public int getCmpFold()
The expected number of data traces per trace ensemble (e.g. the CMP fold).
public SegyFileHeader.Sorting getSorting()
I.e. type of ensemble.
public int getVerticalSum()
1 = no sum, 2 = two sum, ..., N = M-1 sum (M = 2 to 32,767)
public int getSweepFrequencyAtStart()
public int getSweepFrequencyAtEnd()
public int getSweepLength()
public SegyFileHeader.SweepType getSweepType()
public int getSweepChannelNo()
public int getSweepTaperLengthAtStart()
Sweep trace taper length in milliseconds at start if tapered (the taper starts at zero time and is effective for this length).
public int getSweepTaperLengthAtEnd()
Sweep trace taper length in milliseconds at end (the ending taper starts at sweep length minus the taper length at end).
public SegyFileHeader.SweepTaperType getSweepTaperType()
public boolean isBinaryGainRecovery()
public SegyFileHeader.AmplitudeRecoveryType getAmplitudeRecoveryType()
public SegyFileHeader.LengthUnit getLengthUnit()
Measurement system: If Location Data stanzas are included in the file, this entry must agree with the Location Data stanza. If there is a disagreement, the last Location Data stanza is the controlling authority.
public SegyFileHeader.ImpulseSignalPolarity getImpulseSignalPolarity()
public SegyFileHeader.VibratoryPolarity getVibratoryPolarity()
This is how much the seismic signal lags pilot signal by.
public SegyVersion getSegyVersion()
Major SEG Y Format Revision Number. This is an 8-bit unsigned value. Thus for SEG Y Revision 2.0, as defined in this document, this will be recorded as 0216. This field is mandatory for all versions of SEG Y, although a value of zero indicates "traditional" SEG Y conforming to the 1975 standard.
public boolean isTraceFixedLength()
Fixed length trace flag. A value of one indicates th at all traces in this SEG Y file are guaranteed to have the same sample interval and number of samples, as specified in Binary File Header bytes 3217-3218 and 3221-3222. A value of zero indicates that the length of the traces in the file may vary and the number of samples in bytes 115-116 of the Standard SEG Trace Header must be examined to determine the actual length of each trace. This field is mandatory for all versions of SEG Y, although a value of zero indicates "traditional" SEG Y.
public int getNExtendedRecords()
Number of 3200-byte, Extended Textual File Header records following the Binary Header. A value of zero indicates there are no Extended Textual File Header records (i.e. this file has no Extended Textual File Header(s)). A value of -1 indicates that there are a variable number of Extended Textual File Header records and the end of the Extended Textual File Header is denoted by an ((SEG: EndText)) stanza in the final record. A positive value indicates that there are exactly that many Extended Textual File Header records. Note that, although the exact number of Extended Textual File Header records may be a useful piece of information, it will not always be known at the time the Binary Header is written and it is not mandatory that a positive value be recorded here. This field is mandatory for all versions of SEG Y, although a value of zero indicates "traditional" SEG Y conforming to the 1975 standard.
public int getMaxCmpFold()
public boolean isTracesCorrelated()
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