EpiSeismic_LineGeometry2d

Derived From:

EpEntity_Entity, EpiSeismic_SeismicGeometry

Capabilties:

read

Column Summary
Type	Name and Description
String ro	KeyString Unique identifier for each table entry.
FloatSeq ro db	CDP The Common Data Point (CDP) values associated to the Map X and Y values.
PointSeq ro db	Extent The 2d line's bounding box in the form of an array of four points.
String ro req db	LineGeometry2dSet The LineGeometry2dSet object which describes a collection of lineGeometries and their common attributes.
ULong ro db	NumControlPoints The number of control points that define the geometry of the 2D line.
ULong ro req db	NumTraces The maximum number of seismic traces which represents the finest binning that can exist for the 2D line.
StringSeq ro db	ShotpointLabel Contains the entire Shotpoint label.
FloatSeq ro req db	ShotpointNumber The numeric Shotpoint associated to the Map X and Y values.
ULongSeq ro db	Trace The trace index, zero-based, identifying the seismic trace associated with each control point.
PointSeq ro req db	XY The Map X and Y values describing the geometry of the 2D line.

 

Columns inherited from EpiSeismic_SeismicGeometry

Comment, Extent, MapDepthCoordinateSystem, MapTimeCoordinateSystem, Name, Notes, NoteTags, SeismicDatasets

 

Columns inherited from EpEntity_Entity

LastModifiedDate, Name, Project, ProjectName, StoreInstallationName, StoreType

 

Column Detail

KeyString

Unique identifier for each table entry.

CDP

The Common Data Point (CDP) values associated to the Map X and Y values. The number of array elements will be NumControlPoints. A zero-length array will be returned if the 2d line contains no valid navigation data.

ShotpointNumber

The numeric Shotpoint associated to the Map X and Y values. If the Shotpoint is alphanumeric, this column only contains the numeric portion of the label. For example, if the Shotpoint is "100A" this column would only contain 100 and exclude the "A". The number of array elements will be NumControlPoints. A zero-length array will be returned if the 2d line contains no valid navigation data.

ShotpointLabel

Contains the entire Shotpoint label. For example, if the Shotpoint is "100A" then "100A" is returned. If the Shotpoint is numeric (e.g. 100) then a stringified form of the numeric (e.g. "100") is returned. It is possible for some of the Shotpoints to be unknown. In this case, the values are set to an empty string. A zero-length array will be returned if the 2d line contains no valid navigation data.

NumControlPoints

The number of control points that define the geometry of the 2D line. This defines the number of array elements returned for the XY, CDP, ShotpointNumber, ShotpointLabel, and Trace columns. Zero will be returned if the 2d line contains no navigation data.

LineGeometry2dSet

The LineGeometry2dSet object which describes a collection of lineGeometries and their common attributes.

Extent

The 2d line's bounding box in the form of an array of four points. Clients should always set the coordinate system when retrieving this column so they know the exact coordinate system the points are returned in; otherwise, the points will be returned in the default coordinate system and each vendor store might have a different default.

Trace

The trace index, zero-based, identifying the seismic trace associated with each control point. The number of array elements will be NumControlPoints. A zero-length array will be returned if the 2d line contains no valid navigation data. This column must be provided when creating depopulated 2d lines (i.e. the NumControlPoints is less than NumTraces).

NumTraces

The maximum number of seismic traces which represents the finest binning that can exist for the 2D line. The trace numbers are index-based and the valid range is from 0 to NumTraces-1. Any trace index number within this range is valid for writing seismic traces to a PostStack2d associated with this LineGeometry2d. The PostStack2d's TraceStart and TraceEnd values should be used for reading seismic traces.

XY

The Map X and Y values describing the geometry of the 2D line. The Z component of the points should be ignored. The number of array elements will be NumControlPoints. A zero-length array will be returned if the 2d line contains no valid navigation data. Most 2d lines only require a few control points to properly define the line geometry even though the 2d line can support thousands of seismic traces (i.e. PostStack2d) or thousands of 2d interpreted grid values (i.e. HorizonGrid1d/HorizonGrid1dProperty). In this case, NumControlPoints will be less than NumTraces. The EpiSeismic_PostStack2d and EpiInterpretation_HorizonGrid1d tables also have XY columns. The PostStack2d and HorizonGrid1d entities can be associated to the same LineGeometry2d. The XY array lengths do not have to be identical to what exists in the LineGeometry2d table. In fact, the PostStack2d XY and HorizonGrid1d XY array lengths do not have to match. The PostStack2d XY range identifies where the first and last non-null seismic trace exists (e.g. reflects the data extent). The HorizonGrid1d XY range identifies where the first and last non-null grid value exists (e.g. reflects the data extent). For example, the 2d line could support 2,000 seismic traces but maybe only a subset of traces have been written (e.g. PostStack2d's TraceStart = 500 and TraceEnd = 1800). It is possible the HorizonGrid1d grid values exist for a subset of the seismic traces (e.g. HorizonGrid1d's TraceStart = 800 and TraceEnd = 1000). This decision was made to minimize the amount of data being transferred. Clients should always set the coordinate system when retrieving this column so they know the exact coordinate system the points are returned in; otherwise, the points will be returned in the default coordinate system and each vendor store might have a different default.