Fast IO operations with SEG-Y files and other basic utilities for working with seismic data.
Supports all revisions of the SEG-Y standard from 2002 (rev 1) to 2023 (rev 2.1).
The SEG technical standards used in the development of this package are:
Free registration may be required to access these documents.
Get the latest stable release with Julia's package manager:
] add SeisKit
The SEG-Y file format is the most widely used format for storing seismic data in the industry. It consists of a textual header, a binary header, optional extended headers, and trace data with individual trace headers.
The SeisKit module exports the Segy submodule to work with SEG-Y files:
julia> using SeisKitAll SEG-Y headers can be retrieved with the Segy.headers function:
th, bh, eh, trh = Segy.headers("test/data/stacked2Drev1.sgy")but they can also be retrieved separately:
julia> th = Segy.textualheader("test/data/stacked2Drev1.sgy")Click to expand output
>C 1 CLIENT COMPANY CREW NO C 2 LINE AREA MAP ID C 3 REEL NO DAY-START OF REEL YEAR OBSERVER C 4 INSTRUMENT: MFG MODEL SERIAL NO C 5 DATA TRACES/RECORD AUXILIARY TRACES/RECORD CDF FOLD C 6 SAMPLE INTERVAL SAMPLES/TRACE BITS/IN BYTES/SAMPPLE C 7 RECORDING FORMAT FORMAT THIS REEL MEASUREMENT SYSTEM C 8 SAMPLE CODE: FLOATING PT FIXED PT FIXED PT-GAIN CORRELATED C 9 GAIN TYPE: FIXED BINSRY FLOATING POINT OTHER C10 FILTERS: ALIAS HZ NOTCH HZ BAND - HZ SLOPE - DB/OCT C11 SOURCE: TYPE NUMBER/POINT POINT INTERVAL C12 PATTERN: LENGTH WIDTH C13 SWEEP: START HZ END HZ LENGTH MS CHANNEL NO TYPE C14 TAPER: START LENGTH MS END LENGTH MS TYPE C15 SPREAD: OFFSET MAX DISTANCE GROUP INTERVAL C16 GEOPHONES: PER GROUP SPACING FREQUENCY MFG MODEL C17 PATTERN: LENGTH WIDTH C18 TRACESSORTED BY: RECORD CDP OTHER C19 AMPLITUDE RECOVRY: NONE SPHERICAL DIV AGC OTHER C20 MAP PROJECTION ZONE ID COORDINATE UNITS C21 PROCESSING: C22 PROCESSING: C23 C24 C25 C26 C27 C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38 C39 SEG Y REV1 C40 END TEXTUAL HEADER
The textual header has a th.content field with the decoded text,
containing all lines C1 to C40. The SEG-Y standard allows both EBCDIC
and ASCII encodings, and SeisKit.jl automatically detects and decodes
the correct format.
julia> bh = Segy.binaryheader("test/data/stacked2Drev1.sgy")Click to expand output
SEG-Y Binary Header ┌─────────────────────────────────────┬───────┐ │ field │ value │ │ Symbol │ Real │ ├─────────────────────────────────────┼───────┤ │ JOB_NUMBER │ 0 │ │ LINE_NUMBER │ 0 │ │ REEL_NUMBER │ 0 │ │ TRACES_PER_ENSEMBLE │ 1 │ │ AUX_TRACES_PER_ENSEMBLE │ 1 │ │ SAMPLE_INTERVAL │ 10000 │ │ ORIGINAL_SAMPLE_INTERVAL │ 0 │ │ SAMPLES_PER_TRACE │ 351 │ │ ORIGINAL_SAMPLES_PER_TRACE │ 351 │ │ SAMPLE_FORMAT_CODE │ 1 │ │ ENSEMBLE_FOLD │ 1 │ │ TRACE_SORTING_CODE │ 4 │ │ VERTICAL_SUM_CODE │ 0 │ │ SWEEP_FREQ_START │ 0 │ │ SWEEP_FREQ_END │ 0 │ │ SWEEP_LENGTH │ 0 │ │ SWEEP_TYPE │ 4 │ │ TRACE_NUMBER_OF_SWEEP_CHANNEL │ 0 │ │ SWEEP_TRACE_TAPER_LENGTH_START │ 0 │ │ SWEEP_TRACE_TAPER_LENGTH_END │ 0 │ │ TAPER_TYPE │ 3 │ │ CORRELATED_TRACES │ 1 │ │ BINARY_GAIN_RECOVERED │ 2 │ │ AMPLITUDE_RECOVERY_METHOD │ 4 │ │ MEASUREMENT_SYSTEM │ 1 │ │ IMPULSE_SIGNAL_POLARITY │ 0 │ │ VIBRATORY_POLARITY_CODE │ 0 │ │ EXTENDED_TRACES_PER_ENSEMBLE │ 0 │ │ EXTENDED_AUX_TRACES_PER_ENSEMBLE │ 0 │ │ EXTENDED_SAMPLES_PER_TRACE │ 0 │ │ EXTENDED_SAMPLE_INTERVAL │ 0.0 │ │ EXTENDED_ORIGINAL_SAMPLE_INTERVAL │ 0.0 │ │ EXTENDED_ORIGINAL_SAMPLES_PER_TRACE │ 0 │ │ EXTENDED_ENSEMBLE_FOLD │ 0 │ │ ENDIAN_CONSTANT │ 0 │ │ MAJOR_REVISION_NUMBER │ 1 │ │ MINOR_REVISION_NUMBER │ 0 │ │ FIXED_LENGTH_TRACE_FLAG │ 256 │ │ EXTENDED_TEXT_HEADER_COUNT │ 0 │ │ MAX_EXTENDED_TRACE_HEADERS │ 0 │ │ SURVEY_TYPE │ 0 │ │ TIME_BASIS_CODE │ 0 │ │ TRACES_IN_FILE │ 0 │ │ FIRST_TRACE_OFFSET │ 0 │ │ TRAILER_RECORDS │ 0 │ └─────────────────────────────────────┴───────┘
The binary header fields can be accessed directly:
julia> bh.SAMPLE_INTERVAL # sample interval in microseconds0x2710
julia> eh = Segy.extendedheaders("test/data/stacked2Drev1.sgy")SeisKit.Segy.ExtendedHeader[]
The extended headers are rarely used in practice. They consist of textual headers similar to the main textual header, but with well-defined formats (a.k.a. stanzas).
julia> trh = Segy.traceheaders("test/data/stacked2Drev1.sgy")Click to expand output
SEG-Y Trace Header
┌─────────────────────────────────────────────┬───────────┐
│ field │ value │
│ Symbol │ Signed │
├─────────────────────────────────────────────┼───────────┤
│ TRACE_NUMBER_IN_LINE │ 1 │
│ TRACE_NUMBER_IN_FILE │ 0 │
│ ORIGINAL_FIELD_RECORD_NUMBER │ 0 │
│ TRACE_NUMBER_IN_ORIGINAL_FIELD_RECORD │ 0 │
│ ENERGY_SOURCE_POINT_NUMBER │ 0 │
│ ENSEMBLE_NUMBER │ 0 │
│ TRACE_NUMBER_IN_ENSEMBLE │ 0 │
│ TRACE_ID_CODE │ 1 │
│ VERTICALLY_SUMMED_TRACES │ 0 │
│ HORIZONTALLY_STACKED_TRACES │ 0 │
│ DATA_USE │ 1 │
│ DISTANCE_SOURCE_RECEIVER │ 0 │
│ RECEIVER_ELEVATION │ 0 │
│ SOURCE_SURFACE_ELEVATION │ 0 │
│ SOURCE_DEPTH_BELOW_SURFACE │ 0 │
│ RECEIVER_DATUM │ 0 │
│ SOURCE_DATUM │ 0 │
│ SOURCE_WATER_DEPTH │ 0 │
│ RECEIVER_WATER_DEPTH │ 0 │
│ ELEVATION_SCALAR │ 1 │
│ COORDINATE_SCALAR │ -100 │
│ SOURCE_X │ 0 │
│ SOURCE_Y │ 0 │
│ RECEIVER_X │ 0 │
│ RECEIVER_Y │ 0 │
│ COORDINATE_UNIT │ 1 │
│ WEATHERING_VELOCITY │ 0 │
│ SUBWEATHERING_VELOCITY │ 0 │
│ SOURCE_UPHOLE_TIME │ 0 │
│ RECEIVER_UPHOLE_TIME │ 0 │
│ SOURCE_STATIC_CORRECTION │ 0 │
│ RECEIVER_STATIC_CORRECTION │ 0 │
│ TOTAL_STATIC_CORRECTION │ 0 │
│ LAG_TIME_A │ 0 │
│ LAG_TIME_B │ 0 │
│ DELAY_RECORDING_TIME │ 0 │
│ MUTE_TIME_START │ 0 │
│ MUTE_TIME_END │ 0 │
│ SAMPLES_IN_TRACE │ 351 │
│ SAMPLE_INTERVAL │ 10000 │
│ GAIN_TYPE │ 0 │
│ INSTRUMENT_GAIN_CONSTANT │ 0 │
│ INSTRUMENT_INITIAL_GAIN │ 0 │
│ CORRELATED_TRACES │ 0 │
│ SWEEP_FREQ_START │ 0 │
│ SWEEP_FREQ_END │ 0 │
│ SWEEP_LENGTH │ 0 │
│ SWEEP_TYPE │ 0 │
│ SWEEP_TRACE_TAPER_LENGTH_START │ 0 │
│ SWEEP_TRACE_TAPER_LENGTH_END │ 0 │
│ TAPER_TYPE │ 0 │
│ ALIAS_FILTER_FREQ │ 0 │
│ ALIAS_FILTER_SLOPE │ 0 │
│ NOTCH_FILTER_FREQ │ 0 │
│ NOTCH_FILTER_SLOPE │ 0 │
│ LOWCUT_FREQ │ 0 │
│ HIGHCUT_FREQ │ 0 │
│ LOWCUT_SLOPE │ 0 │
│ HIGHCUT_SLOPE │ 0 │
│ YEAR_DATA_RECORDED │ 0 │
│ DAY_OF_YEAR │ 0 │
│ HOUR_OF_DAY │ 0 │
│ MINUTE_OF_HOUR │ 0 │
│ SECOND_OF_MINUTE │ 0 │
│ TIME_BASIS_CODE │ 0 │
│ TRACE_WEIGHTING_FACTOR │ 0 │
│ GROUP_NUMBER_ROW_SWITCH_POS_ONE │ 0 │
│ GROUP_NUMBER_FIRST_TRACE_IN_ORIGINAL_RECORD │ 0 │
│ GROUP_NUMBER_LAST_TRACE_IN_ORIGINAL_RECORD │ 0 │
│ GAP_SIZE │ 0 │
│ TAPER_OVER_TRAVEL │ 0 │
│ ENSEMBLE_X │ 47320112 │
│ ENSEMBLE_Y │ 719430976 │
│ INLINE_NUMBER │ 0 │
│ CROSSLINE_NUMBER │ 7200 │
│ SHOTPOINT_NUMBER │ 2400 │
│ SHOTPOINT_SCALAR │ 0 │
│ TRACE_MEASUREMENT_UNIT │ 0 │
│ TRANSDUCTION_CONSTANT │ 0 │
│ TRANSDUCTION_CONSTANT_EXPONENT │ 0 │
│ TRANSDUCTION_CONSTANT_UNIT │ 0 │
│ DEVICE_NUMBER │ 0 │
│ TIME_SCALAR │ 0 │
│ SOURCE_TYPE_ORIENTATION │ 0 │
│ SOURCE_DIRECTION_VERTICAL │ 0 │
│ SOURCE_DIRECTION_CROSSLINE │ 0 │
│ SOURCE_DIRECTION_INLINE │ 0 │
│ SOURCE_CONSTANT │ 0 │
│ SOURCE_CONSTANT_EXPONENT │ 0 │
│ SOURCE_CONSTANT_UNIT │ 0 │
└─────────────────────────────────────────────┴───────────┘
.
.
.
SEG-Y Trace Header
┌─────────────────────────────────────────────┬───────────┐
│ field │ value │
│ Symbol │ Signed │
├─────────────────────────────────────────────┼───────────┤
│ TRACE_NUMBER_IN_LINE │ 7701 │
│ TRACE_NUMBER_IN_FILE │ 0 │
│ ORIGINAL_FIELD_RECORD_NUMBER │ 0 │
│ TRACE_NUMBER_IN_ORIGINAL_FIELD_RECORD │ 0 │
│ ENERGY_SOURCE_POINT_NUMBER │ 0 │
│ ENSEMBLE_NUMBER │ 0 │
│ TRACE_NUMBER_IN_ENSEMBLE │ 0 │
│ TRACE_ID_CODE │ 1 │
│ VERTICALLY_SUMMED_TRACES │ 0 │
│ HORIZONTALLY_STACKED_TRACES │ 0 │
│ DATA_USE │ 1 │
│ DISTANCE_SOURCE_RECEIVER │ 0 │
│ RECEIVER_ELEVATION │ 0 │
│ SOURCE_SURFACE_ELEVATION │ 0 │
│ SOURCE_DEPTH_BELOW_SURFACE │ 0 │
│ RECEIVER_DATUM │ 0 │
│ SOURCE_DATUM │ 0 │
│ SOURCE_WATER_DEPTH │ 0 │
│ RECEIVER_WATER_DEPTH │ 0 │
│ ELEVATION_SCALAR │ 1 │
│ COORDINATE_SCALAR │ -100 │
│ SOURCE_X │ 0 │
│ SOURCE_Y │ 0 │
│ RECEIVER_X │ 0 │
│ RECEIVER_Y │ 0 │
│ COORDINATE_UNIT │ 1 │
│ WEATHERING_VELOCITY │ 0 │
│ SUBWEATHERING_VELOCITY │ 0 │
│ SOURCE_UPHOLE_TIME │ 0 │
│ RECEIVER_UPHOLE_TIME │ 0 │
│ SOURCE_STATIC_CORRECTION │ 0 │
│ RECEIVER_STATIC_CORRECTION │ 0 │
│ TOTAL_STATIC_CORRECTION │ 0 │
│ LAG_TIME_A │ 0 │
│ LAG_TIME_B │ 0 │
│ DELAY_RECORDING_TIME │ 0 │
│ MUTE_TIME_START │ 0 │
│ MUTE_TIME_END │ 0 │
│ SAMPLES_IN_TRACE │ 351 │
│ SAMPLE_INTERVAL │ 10000 │
│ GAIN_TYPE │ 0 │
│ INSTRUMENT_GAIN_CONSTANT │ 0 │
│ INSTRUMENT_INITIAL_GAIN │ 0 │
│ CORRELATED_TRACES │ 0 │
│ SWEEP_FREQ_START │ 0 │
│ SWEEP_FREQ_END │ 0 │
│ SWEEP_LENGTH │ 0 │
│ SWEEP_TYPE │ 0 │
│ SWEEP_TRACE_TAPER_LENGTH_START │ 0 │
│ SWEEP_TRACE_TAPER_LENGTH_END │ 0 │
│ TAPER_TYPE │ 0 │
│ ALIAS_FILTER_FREQ │ 0 │
│ ALIAS_FILTER_SLOPE │ 0 │
│ NOTCH_FILTER_FREQ │ 0 │
│ NOTCH_FILTER_SLOPE │ 0 │
│ LOWCUT_FREQ │ 0 │
│ HIGHCUT_FREQ │ 0 │
│ LOWCUT_SLOPE │ 0 │
│ HIGHCUT_SLOPE │ 0 │
│ YEAR_DATA_RECORDED │ 0 │
│ DAY_OF_YEAR │ 0 │
│ HOUR_OF_DAY │ 0 │
│ MINUTE_OF_HOUR │ 0 │
│ SECOND_OF_MINUTE │ 0 │
│ TIME_BASIS_CODE │ 0 │
│ TRACE_WEIGHTING_FACTOR │ 0 │
│ GROUP_NUMBER_ROW_SWITCH_POS_ONE │ 0 │
│ GROUP_NUMBER_FIRST_TRACE_IN_ORIGINAL_RECORD │ 0 │
│ GROUP_NUMBER_LAST_TRACE_IN_ORIGINAL_RECORD │ 0 │
│ GAP_SIZE │ 0 │
│ TAPER_OVER_TRAVEL │ 0 │
│ ENSEMBLE_X │ 46642304 │
│ ENSEMBLE_Y │ 719775424 │
│ INLINE_NUMBER │ 0 │
│ CROSSLINE_NUMBER │ 7500 │
│ SHOTPOINT_NUMBER │ 2500 │
│ SHOTPOINT_SCALAR │ 0 │
│ TRACE_MEASUREMENT_UNIT │ 0 │
│ TRANSDUCTION_CONSTANT │ 0 │
│ TRANSDUCTION_CONSTANT_EXPONENT │ 0 │
│ TRANSDUCTION_CONSTANT_UNIT │ 0 │
│ DEVICE_NUMBER │ 0 │
│ TIME_SCALAR │ 0 │
│ SOURCE_TYPE_ORIENTATION │ 0 │
│ SOURCE_DIRECTION_VERTICAL │ 0 │
│ SOURCE_DIRECTION_CROSSLINE │ 0 │
│ SOURCE_DIRECTION_INLINE │ 0 │
│ SOURCE_CONSTANT │ 0 │
│ SOURCE_CONSTANT_EXPONENT │ 0 │
│ SOURCE_CONSTANT_UNIT │ 0 │
└─────────────────────────────────────────────┴───────────┘
The trace headers are stored in a vector-like data structure that allows easy access to individual fields without unnecessary memory copies:
julia> trh.ENSEMBLE_X # vector of ensemble x coordinates7701-element FieldViews.FieldView{:ENSEMBLE_X, Int32, 1, SeisKit.Segy.TraceHeader, Vector{SeisKit.Segy.TraceHeader}}:
47320112
47320864
47321616
47322364
47323116
47323868
47324620
⋮
46637800
46638552
46639300
46640052
46640804
46641552
46642304
julia> trh[1].CROSSLINE_NUMBER # crossline number of the first trace7200
The actual seismic data can be retrieved with the Segy.load
function. It calls Segy.headers and then Segy.traces
to read the data efficiently into Julia arrays:
julia> seismic = Segy.load("test/data/stacked2Drev1.sgy")SEG-Y Dataset (rev 1.0)
├─ Nᵒ traces: 7701
├─ Nᵒ samples: 351 (fixed)
├─ Inlines: 0 (fixed)
└─ X-lines: 7200 ─ 7500
The arrays are stored in the seismic.traces field. The Segy.save
function can be used to write the data back to a file that is compliant
with SEG-Y rev 2.1:
julia> Segy.save("path/to/newfile.sgy", seismic)We do not support saving in older revisions because:
The SEG Technical Standards Committee strongly encourages producers and users of SEG-Y data sets to move to the revised (2.1) standard in an expeditious fashion.
The trace positions can be retrieved with the Segy.positions function.
The package automatically detects the coordinate reference system (CRS)
using various heuristics. If no CRS is found, the function returns a generic
Cartesian system with units in meters.
julia> Segy.positions(seismic)Click to expand output
7701-element Vector{Meshes.Point{Meshes.𝔼{2}, CoordRefSystems.Cartesian2D{CoordRefSystems.WGS84Latest, Unitful.Quantity{Float64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}}}}:
Point(x: 473201.12 m, y: 7.19430976e6 m)
Point(x: 473208.64 m, y: 7.1943328e6 m)
Point(x: 473216.16 m, y: 7.19435712e6 m)
Point(x: 473223.64 m, y: 7.1943808e6 m)
Point(x: 473231.16 m, y: 7.19440448e6 m)
Point(x: 473238.68 m, y: 7.1944288e6 m)
⋮
Point(x: 466385.52 m, y: 7.1976352e6 m)
Point(x: 466393.0 m, y: 7.19765888e6 m)
Point(x: 466400.52 m, y: 7.19768256e6 m)
Point(x: 466408.04 m, y: 7.19770624e6 m)
Point(x: 466415.52 m, y: 7.19773056e6 m)
Point(x: 466423.04 m, y: 7.19775424e6 m)
In the case of 2D seismic with fixed-length traces (e.g., 2D post-stack),
it is often useful to place the traces side by side to form an image.
For that, we provide the Segy.matrix and Segy.image functions.
The Segy.matrix function sorts the traces based on their positions,
and returns a simple 2D array (i.e., matrix) without geospatial information:
julia> Segy.matrix(seismic)Click to expand output
351×7701 Matrix{Float64}:
1496.38 1496.4 1496.4 1496.39 1496.37 1496.36 1496.37 1496.39 1496.42 … 1497.82 1497.72 1497.51 1497.05 1496.64 1496.29 1495.98 1495.73
1496.38 1496.4 1496.4 1496.39 1496.37 1496.36 1496.37 1496.39 1496.42 1497.82 1497.72 1497.51 1497.05 1496.64 1496.29 1495.98 1495.73
1493.5 1493.51 1493.5 1493.49 1493.46 1493.44 1493.44 1493.45 1493.47 1494.6 1494.51 1494.33 1493.94 1493.59 1493.29 1493.03 1492.81
1490.57 1490.57 1490.55 1490.53 1490.5 1490.47 1490.46 1490.46 1490.46 1491.32 1491.24 1491.09 1490.77 1490.49 1490.24 1490.03 1489.85
1487.21 1487.19 1487.16 1487.13 1487.1 1487.06 1487.04 1487.02 1487.01 1487.55 1487.48 1487.36 1487.12 1486.91 1486.73 1486.56 1486.42
1484.38 1484.35 1484.31 1484.27 1484.23 1484.19 1484.16 1484.13 1484.1 … 1484.84 1484.78 1484.68 1484.5 1484.35 1484.21 1484.09 1483.99
1483.24 1483.19 1483.15 1483.11 1483.08 1483.05 1483.01 1482.96 1482.91 1484.61 1484.56 1484.47 1484.36 1484.26 1484.18 1484.11 1484.06
1485.9 1485.84 1485.8 1485.77 1485.76 1485.74 1485.69 1485.64 1485.57 1487.23 1487.18 1487.12 1487.09 1487.07 1487.05 1487.05 1487.05
⋮ ⋮ ⋱ ⋮ ⋮
4306.74 4310.65 4315.24 4319.14 4324.03 4326.27 4321.0 4318.07 4317.0 4122.27 4122.17 4122.27 4122.27 4122.27 4122.27 4122.17 4122.07
4140.14 4140.73 4141.51 4142.19 4142.88 4143.07 4142.19 4141.61 4141.7 4122.27 4122.46 4122.56 4122.56 4122.66 4122.56 4122.56 4122.37
4135.45 4135.84 4136.33 4136.62 4137.11 4137.41 4137.41 4137.5 4137.6 … 4118.46 4118.66 4118.75 4118.75 4118.56 4118.56 4118.27 4118.17
4134.87 4135.65 4136.23 4137.11 4137.8 4138.29 4138.19 4138.19 4138.29 4121.88 4121.78 4121.78 4121.88 4122.17 4122.27 4122.46 4122.46
4137.6 4137.99 4138.48 4138.97 4139.75 4140.04 4140.14 4140.14 4140.14 4134.67 4133.99 4133.3 4133.3 4133.4 4134.18 4134.87 4135.65
4143.17 4142.29 4141.51 4140.63 4139.75 4139.26 4139.26 4139.36 4139.46 4278.62 4274.52 4272.37 4277.05 4281.84 4286.14 4290.73 4294.83
4147.07 4145.41 4143.66 4141.9 4140.04 4139.16 4139.16 4139.26 4139.36 4382.23 4381.84 4382.33 4384.18 4386.14 4387.11 4388.48 4389.85
4146.59 4145.22 4143.95 4142.58 4141.12 4140.04 4140.04 4139.95 4139.95 … 4579.3 4575.69 4570.8 4573.44 4576.57 4579.01 4582.43 4583.4
The Segy.image function performs the additional step of georeferencing
the matrix over a structured grid, returning a GeoTable object:
julia> img = Segy.image(seismic)Click to expand output
2695000×2 GeoTable over 350×7700 StructuredGrid
┌────────────┬───────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ signal │ geometry │
│ Continuous │ Quadrangle │
│ [NoUnits] │ � Cartesian{NoDatum} │
├────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ 1497.87 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: 0.0 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: 0.0 m)) │
│ 1497.87 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -40.1143 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -40.1143 m)) │
│ 1494.58 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -80.2286 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -80.2286 m)) │
│ 1491.23 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -120.343 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -120.343 m)) │
│ 1487.38 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -160.457 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -160.457 m)) │
│ 1484.58 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -200.571 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -200.571 m)) │
│ 1484.19 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -240.686 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -240.686 m)) │
│ 1486.54 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -280.8 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -280.8 m)) │
│ 1488.79 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -320.914 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -320.914 m)) │
│ 1491.16 │ Quadrangle((x: 4.66048e5 m, y: 7.19656e6 m, z: -361.029 m), ..., (x: 4.66055e5 m, y: 7.19659e6 m, z: -361.029 m)) │
│ ⋮ │ ⋮ │
└────────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
2694990 rows omitted
An optional velocity value can be provided to scale the time/depth axis.
By default, the velocity is set to 4000 m/s (marine sedimentary rocks).
### Troubleshooting
We provide the `Segy.report` function to report header information
and highlight issues with SEG-Y files. It can be useful to spot files
that are not compliant with the standard, and to anticipate potential
problems when loading the data:
```julia
julia> Segy.report("test/data/stacked2Drev1.sgy")Click to expand output
C 1 CLIENT COMPANY CREW NO C 2 LINE AREA MAP ID C 3 REEL NO DAY-START OF REEL YEAR OBSERVER C 4 INSTRUMENT: MFG MODEL SERIAL NO C 5 DATA TRACES/RECORD AUXILIARY TRACES/RECORD CDF FOLD C 6 SAMPLE INTERVAL SAMPLES/TRACE BITS/IN BYTES/SAMPPLE C 7 RECORDING FORMAT FORMAT THIS REEL MEASUREMENT SYSTEM C 8 SAMPLE CODE: FLOATING PT FIXED PT FIXED PT-GAIN CORRELATED C 9 GAIN TYPE: FIXED BINSRY FLOATING POINT OTHER C10 FILTERS: ALIAS HZ NOTCH HZ BAND - HZ SLOPE - DB/OCT C11 SOURCE: TYPE NUMBER/POINT POINT INTERVAL C12 PATTERN: LENGTH WIDTH C13 SWEEP: START HZ END HZ LENGTH MS CHANNEL NO TYPE C14 TAPER: START LENGTH MS END LENGTH MS TYPE C15 SPREAD: OFFSET MAX DISTANCE GROUP INTERVAL C16 GEOPHONES: PER GROUP SPACING FREQUENCY MFG MODEL C17 PATTERN: LENGTH WIDTH C18 TRACESSORTED BY: RECORD CDP OTHER C19 AMPLITUDE RECOVRY: NONE SPHERICAL DIV AGC OTHER C20 MAP PROJECTION ZONE ID COORDINATE UNITS C21 PROCESSING: C22 PROCESSING: C23 C24 C25 C26 C27 C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38 C39 SEG Y REV1 C40 END TEXTUAL HEADERSEG-Y Binary Header┌─────────────────────────────────────┬───────┐ │ field │ value │ │ Symbol │ Real │ ├─────────────────────────────────────┼───────┤ │ JOB_NUMBER │ 0 │ │ LINE_NUMBER │ 0 │ │ REEL_NUMBER │ 0 │ │ TRACES_PER_ENSEMBLE │ 1 │ │ AUX_TRACES_PER_ENSEMBLE │ 1 │ │ SAMPLE_INTERVAL │ 10000 │ │ ORIGINAL_SAMPLE_INTERVAL │ 0 │ │ SAMPLES_PER_TRACE │ 351 │ │ ORIGINAL_SAMPLES_PER_TRACE │ 351 │ │ SAMPLE_FORMAT_CODE │ 1 │ │ ENSEMBLE_FOLD │ 1 │ │ TRACE_SORTING_CODE │ 4 │ │ VERTICAL_SUM_CODE │ 0 │ │ SWEEP_FREQ_START │ 0 │ │ SWEEP_FREQ_END │ 0 │ │ SWEEP_LENGTH │ 0 │ │ SWEEP_TYPE │ 4 │ │ TRACE_NUMBER_OF_SWEEP_CHANNEL │ 0 │ │ SWEEP_TRACE_TAPER_LENGTH_START │ 0 │ │ SWEEP_TRACE_TAPER_LENGTH_END │ 0 │ │ TAPER_TYPE │ 3 │ │ CORRELATED_TRACES │ 1 │ │ BINARY_GAIN_RECOVERED │ 2 │ │ AMPLITUDE_RECOVERY_METHOD │ 4 │ │ MEASUREMENT_SYSTEM │ 1 │ │ IMPULSE_SIGNAL_POLARITY │ 0 │ │ VIBRATORY_POLARITY_CODE │ 0 │ │ EXTENDED_TRACES_PER_ENSEMBLE │ 0 │ │ EXTENDED_AUX_TRACES_PER_ENSEMBLE │ 0 │ │ EXTENDED_SAMPLES_PER_TRACE │ 0 │ │ EXTENDED_SAMPLE_INTERVAL │ 0.0 │ │ EXTENDED_ORIGINAL_SAMPLE_INTERVAL │ 0.0 │ │ EXTENDED_ORIGINAL_SAMPLES_PER_TRACE │ 0 │ │ EXTENDED_ENSEMBLE_FOLD │ 0 │ │ ENDIAN_CONSTANT │ 0 │ │ MAJOR_REVISION_NUMBER │ 1 │ │ MINOR_REVISION_NUMBER │ 0 │ │ FIXED_LENGTH_TRACE_FLAG │ 256 │ │ EXTENDED_TEXT_HEADER_COUNT │ 0 │ │ MAX_EXTENDED_TRACE_HEADERS │ 0 │ │ SURVEY_TYPE │ 0 │ │ TIME_BASIS_CODE │ 0 │ │ TRACES_IN_FILE │ 0 │ │ FIRST_TRACE_OFFSET │ 0 │ │ TRAILER_RECORDS │ 0 │ └─────────────────────────────────────┴───────┘
SEG-Y Trace Header Summary (non-zero fields only) ┌──────────────────────┬───────────┬───────────┐ │ field │ minimum │ maximum │ │ Symbol │ Int64 │ Int64 │ ├──────────────────────┼───────────┼───────────┤ │ TRACE_NUMBER_IN_LINE │ 1 │ 7701 │ │ TRACE_ID_CODE │ 1 │ 1 │ │ DATA_USE │ 1 │ 1 │ │ ELEVATION_SCALAR │ 1 │ 1 │ │ COORDINATE_SCALAR │ -100 │ -100 │ │ COORDINATE_UNIT │ 1 │ 1 │ │ SAMPLES_IN_TRACE │ 351 │ 351 │ │ SAMPLE_INTERVAL │ 10000 │ 10000 │ │ ENSEMBLE_X │ 46604756 │ 47357660 │ │ ENSEMBLE_Y │ 719430976 │ 719775424 │ │ CROSSLINE_NUMBER │ 7200 │ 7500 │ │ SHOTPOINT_NUMBER │ 2400 │ 2500 │ └──────────────────────┴───────────┴───────────┘
SEG-Y issues report:
- Detected FIXED_LENGTH_TRACE_FLAG = 256 in binary header. FIXED_LENGTH_TRACE_FLAG should be 0 or 1.
You can fix most of these issues with Segy.save(...)
after loading the data with Segy.load(...).
If Segy.report shows issues that you want to fix manually,
you can modify the Segy.headers, create a Segy.Dataset
with the modified headers and traces, and then save it with
Segy.save. The Segy.save function fixes most issues found
in the headers using the Segy.fixissues function before
writing the new file in SEG-Y rev 2.1.
Please consult the docstrings of all these functions for more details.
Contributions are very welcome. Please open an issue if you have questions.
Packages with similar functionality were written for older versions of the language:
-
SegyIO.jl provides read/write functions for SEG-Y rev 1 that are ~1.5x slower than SeisKit.jl on average. That is because SeisKit.jl adopted more idiomatic Julia coding styles and optimized IO operations more aggressively.
-
SeisIO.jl provides tools for SEG-Y rev 0 and rev 1 files, and other seismic data formats. However, it is not actively maintained anymore, and has too many unnecessary dependencies for an IO package.
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