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The Select data by polygon module extracts a spatial subset of seismic traces that fall within a user-defined polygon boundary. Given the sorted trace headers of a seismic dataset and a polygon file defining the area of interest in map coordinates, the module tests each trace location against the polygon and writes only the traces inside the boundary to a new output file. This is useful for limiting subsequent processing to a specific survey area, a licence block, or a region of geological interest without physically cropping the source data.
The handle to the source SEG-Y dataset from which traces will be selected. Connect to the output handle of the Open SEG-Y module.
The sorted trace header index providing the X/Y or inline/crossline coordinates used to test each trace against the polygon. Connect to the sorted headers output of the preceding Sort Traces or Open SEG-Y module.
The full path to a text file defining the polygon boundary. The file contains a list of X/Y coordinate pairs (one pair per line) that form a closed polygon. Coordinates must be in the same coordinate system as the trace header positions in the input seismic data. Polygons can be exported from GIS software or created directly in g-Platform using the Polygon Picking module.
When enabled, the polygon coordinates are converted from feet to metres before testing against the trace header positions. Enable this option when the polygon file was created in a feet-based coordinate system but the seismic trace headers use metres. Default: disabled.
The full path and filename for the output GSD seismic file containing only the traces that fall within the polygon boundary. All trace header fields are preserved in the output. The output can be used directly as the input to subsequent processing modules.