Apply Elevations to Geometry from ASCII module updates source and/or receiver elevation values in seismic geometry using elevation information provided in an external ASCII text file. The module matches records from the input file to existing seismic geometry based on line and point identifiers and applies the elevation values directly to trace headers.
This approach allows elevation corrections or survey updates to be applied without reloading seismic data or rebuilding geometry from scratch.
When to use this module?
Use this module when:
•Elevation information becomes available after geometry loading
•Surveyed elevations need to replace placeholder or incorrect values
•Elevation corrections are required prior to statics or imaging
How it works?
•Reads elevation records from the specified ASCII file
•Applies coordinate and elevation scaling as required
•Matches file records to seismic geometry using line and point numbers
•Updates elevation headers for selected targets (sources and/or receivers)
Only elevation values are modified.
Supported input files:
•Tab-delimited text files
•Space-delimited (formatted) text files
•Comma-separated values (CSV) files
The input file must contain at least line, point number, and elevation columns.
Output:
•Source and/or receiver elevation headers are updated in place
•No new traces or geometry objects are created
•Existing seismic data samples are not modified
Geometry points - these are typically the coordinate points which are used to assign the elevation information from the input elevation file. Connect/reference to coordinates and locations of the input trace headers. This is usually from "Load geometry from SPS" or Load geometry from ASCII, Load geometry from P190 etc modules.
Elevations file - specifies the ASCII text file & location containing elevation data to be applied to seismic geometry.
Line - specifies the seismic line name used to match elevation records to geometry. Required when multiple lines are present.
Measurement system { Feet, Meter } - specifies the unit system used for elevation values in the input file. By default, Meter.
Target net { Sources, Receivers, Sources and receivers } - selects which geometry objects are updated using the elevation file. Select the options from the drop down menu.
Coordinate scalar - scaling factor applied to X and Y coordinates read from the file before matching. Used to convert integer or scaled coordinates to real values. By default, 1.
Elevation scalar - scaling factor applied to elevation values read from the file. Used to convert stored integer elevations to real units. By default, 1.
Automatic header detection - this option automatically detects the input elevation file headers. By default, TRUE (Checked).
File read parameters - specify the input elevation file read parameters
Header row - specify the header row position. By default, 1.
Start row - specify the start row position. By default, 1.
File type { Tab delimited, Space delimited, CSV, Manual } - specifies the delimiter format used in the input elevation file. Supported formats include Tab delimited, Space delimited, CSV, and Manual. Select the option from the drop down menu and provide the respective parameter.
File type - Tab delimited - indicates that columns in the elevation file are separated by tab characters.
Line name column - specifies the column containing the seismic line identifier in the input file.
SP column - specifies the column name containing the source or receiver point number used for matching geometry.
X column - specifies the column name containing the X coordinate value in the elevation file.
Y column - specifies the column name containing the Y coordinate value in the elevation file.
Elevation column - specifies the column name containing the elevation value to be applied to geometry.
File type - Space delimited - indicates that columns in the elevation file are separated by space characters.
File type - CSV - indicates that columns in the elevation file are separated by comma characters.
File type - Manual - indicates that columns in the elevation file are not in any standard format. The user has to provide the respective column positions.
Line name position - specify the line name position from the input elevation file.
SP position - specify the source/receiver point number position from the input elevation file.
X position - specify the X coordinate position from the input elevation file.
Y position - specify the Y coordinate position from the input elevation file.
Elevation position - specify the elevation value position from the input elevation file.
Skip - By default, FALSE(Unchecked). This option helps to bypass the module from the workflow.
Geometry points out - outputs the updated trace headers with the elevation information.
Elevations table - outputs elevation as a table.
Sources geometry table output - outputs source geometry table as an output.
Receivers geometry table output - outputs receiver geometry table as an output.
There is no information available for this module.
In this example workflow, we are updating the elevation information where elevation information was not present in the navigation data.
We've to connect/reference to coordinates points. In the parameters tab, we've to provide the input elevation file in ASCII format. Choose the correct file type and measurement units from the drop down menu. In case the file format is not a standard format, the user should provide the column positions manually.
Adjust the parameters as per the input data requirements and execute the module. QC the elevations before and after.
There are no action items available for this module so the user can ignore it.
YouTube video lesson, click here to open [VIDEO IN PROCESS...]
Yilmaz. O., 1987, Seismic data processing: Society of Exploration Geophysicist
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