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ImportCroockedLine loads a pre-existing crooked (stack) line from an external ASCII file and registers it as the active 2D stack line geometry in the current project. Use this module when the stack line was previously computed — either by the Create Stack Line module or exported from another application — and you want to reuse it without recalculating it from scratch.
The module reads a tab-delimited ASCII file with one bin point per row (columns: sequence number, X coordinate, Y coordinate). After loading, it can optionally smooth the line geometry and resample it to a uniform bin spacing. Topographic elevations for each bin point are assigned by finding the nearest source or receiver point from the trace headers (for 2D surveys) or by interpolating from the BinGrid topography map (for 3D surveys). Exactly one of these two topography inputs must be connected.
Note: This module is deprecated. For new projects, use the Create Stack Line module to build the crooked line geometry directly from trace headers.
The trace header collection for a 2D seismic survey. When connected, the module uses the source and receiver coordinates stored in these headers to assign ground-surface elevations to each bin point on the imported line. Connect this input for land 2D surveys. Exactly one of this input or the BinGrid item must be connected — connecting both or neither will produce an error.
The BinGrid item for a 3D survey that contains a topography map. When connected, the module interpolates surface elevations for each bin point from the topography layer stored in the BinGrid. Connect this input for 3D survey projects where the crooked line will be extracted as a 2D section through a 3D volume. Exactly one of this input or the Trace headers must be connected.
The path to the ASCII file containing the crooked line point coordinates. The file must be tab-delimited with three columns per row: an integer sequence number, the X coordinate, and the Y coordinate of each bin center point. The expected file extension is .dat. This file is typically produced by the Create Stack Line module or exported from another processing system. The coordinate units must match the survey coordinate system and the unit scale set in the Crooked line scale parameter.
Specifies the unit system in which the X and Y coordinates are stored in the input file. Select Meters if the file coordinates are in metres (default), or Feets if they are in feet. When Feets is selected, coordinates are automatically converted to metres (1 ft = 0.3048 m) before the line is used in processing. Choosing the wrong setting will shift all bin positions by a factor of ~3.3 and corrupt the geometry.
The total length of the smoothing window applied to the imported line geometry, in metres. Smoothing removes sharp kinks or digitisation noise from the loaded coordinates and produces a more regular bin-center curve. The default value is 0 m, which disables smoothing entirely. To enable smoothing, set both Smooth Window Len and Smooth Step to values greater than zero. A typical value might be 200–500 m for land surveys with noisy line coordinates. Use larger values for a stronger smoothing effect.
The point spacing used internally during the smoothing calculation, in metres. This value defines the denominator for the smoothing filter length: the effective number of smoothing passes is Smooth Window Len divided by Smooth Step. The default is 0 m, which disables smoothing. Set this to a value representative of the average point spacing in the input file (for example, the nominal CMP interval). Both Smooth Window Len and Smooth Step must be non-zero to activate smoothing.
The desired uniform bin spacing for the output stack line, in metres. When set to a positive value, the module resamples the loaded (and optionally smoothed) line so that successive bin points are spaced exactly this distance apart. Set this to match your target CMP bin interval — for example, 12.5 m or 25 m. The default value is 0 m, which preserves the original point spacing from the input file without resampling. Use a non-zero value when you need the output line to have a uniform, controlled bin interval regardless of how the input file was digitised.