Merging multiple seismic files to make it one single file
Concatenation in seismic data processing means joining two or more seismic files end-to-end to form a single continuous file. It’s like merging multiple SEG-Y files into one large dataset containing all traces in sequence. Within g-Platform, we can concatenate both internal and external (SEG-Y) files.
Purpose
•To combine shot gathers or lines recorded in parts.
•To merge reels or tape volumes that belong to the same survey.
•To prepare continuous input for later processing steps (e.g., sorting, geometry setup, stacking).
•To simplify data handling — fewer files, consistent headers, and uniform parameters.
When We Do It
•When a survey is recorded in multiple reels/tapes.
•After split processing (e.g., processed in batches per line or swath).
•When importing field data divided into shot groups.
•Before global operations (QC, filtering, velocity analysis) that require all traces in one file.
Important Considerations
•Header consistency: All files must have the same format (sample rate, samples/trace, data format, byte order).
•Sequence numbers: After concatenation, trace numbering often needs to be recreated to maintain a continuous sequence.
•CDP and geometry fields: Should be checked — overlapping CDP or shot numbers may need correction.
•End-of-file headers: Remove duplicate file headers if the software doesn’t handle them automatically.
•QC check: Always verify total trace count, sample rate, and continuity after merging.
All input files should be provided in the Parameters section.
SEG-Y format
Data type { Land, Marine, Transition } - specify the input data type from the drop down menu. There are 3 types available. Land, Marine, Transition.
Text header size - text header stores the survey and processing history information. This is in ASCII format. The default size is 3200 bytes. This is also known as EBCDIC header. The standard size of the text header is 40 rows and 80 columns.
Binary header size - this header stores the data in binary format. Default size is 400 bytes. In this header, we get sample interval, no of samples, measurement system, data format (IBM, floating point, ....) etc. information is stored.
Endian { Big, Little } - it refers to the byte order in which a computer stores the multi byte (integers, floating point etc) data in memory or files.
Big Endian - Most Significant Byte is stored at Lowest memory address. Most old computers used Big Endian.
Little Endian - Least Significant Byte is stored at Lowest memory address. Modern computes uses Little Endian.
EBCDIC - displays the EBCDIC/text header if this option is TRUE (Checked). By default, TRUE (Checked).
Data Sample format { Default, IBMFloat4, Int4, Int2, Float4, Int1 } - it represents the seismic trace amplitudes in binary format. It defined in 25-26 byte location of SEG-Y binary header. By default, IEEE (most modern systems uses this). Incorrect data sample format leads to wrong amplitudes, clipping of high/low amplitudes etc. It is also important that both data sample format and Endian type are accurate and correct.
Default - IEEE format
IBMFloat4 - IBM 32 bit Floating point with 4 Bytes as sample size. Most legacy SEGY data is in this format.
Int4 - 32 bit Integer point with 4 Bytes as sample size.
Int2 - 16 bit Integer point with 2 Bytes as sample size.
Float4 - IEEE 32 bit Floating point with 4 Bytes as sample size. Modern SEGY data is in this format.
Int1 - 8 bit Integer point with 1 Byte as sample size.
Gather domain { TIME, DEPTH, FREQUENCY } - allows the user to specify the input data domain type. By default, Time. There are additional domain options available from the drop down menu.
Time - Input data is in Time domain
Depth - Input data is in Depth domain
Frequency - Input data is in Frequency domain
Trace header format - it contains meta data of the seismic trace which means all the parameters like source point, FFID, channel number, source and receiver coordinates etc., are stored at certain byte locations. This is very crucial while reading the SEG-Y data. Make sure that the trace headers mapped correctly to their respective byte locations with correct format.
Geomage format - By default, Geomage format. This is a standard SEG-Y rev 1.0 format.
Seismic file mask - this allows the user to add multiple files at a time without selecting each file individually. The user must provide common name of all input files with the combination of special characters.
Input SEG-Y files - select the input SEG-Y files by clicking the 
icon. This opens a new window where the user should provide the file name and path.
Input GSD files - select the g-Platform internal file format files by clicking the icon.
Input GSDL files - select the g-Platform software internal linked files.
Save to.. { SGY, GSD, GSDL } - choose the appropriate output format to save the output file. By default, SGY.
Save to.. - SGY - this option saves the final output file after concatenating all input files in SEG-Y format.
Output file name - provide the output file name with an extension of .SGY/SEGY
Compress { 32 bits, 16 bits, 8 bits } - this allows the user to compress the output file size to reduce the overall size of the output data. By default, 32 bit. The lower the compress rate the smaller the file size however 16 bits compression is recommended. This option won't impact the seismic data.
Save to.. - GSD - this option saves the final output in g-Platform internal file format.
Output file name - provide the output file name. It saves the final output file with an extension of ".gsd"
Compress { 32 bits, 16 bits, 8 bits } - this allows the user to compress the output file size to reduce the overall size of the output data. By default, 32 bit. The lower the compress rate the smaller the file size however 16 bits compression is recommended. This option won't impact the seismic data.
Save to.. - GSDL - this option saves the final output file as g-Platform internal file format.
Output file name - provide the output file name. Final output file will be saved with an extension of ".gsdl".
Output gather domain { TIME, DEPTH, FREQUENCY } - choose the output gather domain. By default, TIME.
Write new - this option allows the user to write a new output file. By default, TRUE (Checked).
Copy binary header from first file in list - this option takes the binary header information from first file in the list of input seismic files and copies to all other. By default, TRUE (Checked).
Maximum number of traces in read bulk - this option allows the user to specify the total number of traces to write at a time as bulk. By default, 10000.
Re-assign FFIDs { None, By file name, By number in collection } - this option reassign FFID's to the final output data. By default,
None - won't reassign FFIDs. Keeps the original FFIDs of each and individual input file.
By file name - reassigns FFIDs based on the file name from the input file list
By number in collection - reassigns FFIDs based on the file number of the input files in the collection table.
Re-assign surveyID - if there are multiple survey IDs are present in the input data files then it will reassign the surveyID. By default, FALSE (Unchecked)
Reset survey names { No, Reset by filename, Reset if name doesn't exist } - it will reset the survey names. By default, No
Reset survey names - No - it won't reset the survey names. Keeps the original survey name.
Reset survey names - Reset by filename - if reset survey name option is checked (TRUE), it will reset the survey names based on the file names.
Reset survey names - Reset if name doesn't exist - this will rest survey names if there is no file name based on the mask provided by the user
Mask to extract survey name from filename - it will extract the survey names from the user provided input files. By default, FALSE (Unchecked).
Prefix - it will add a prefix to the survey name. By default, Survey1
Mask starts with - specify any prefixes for the input file names to read all the input files
Mask ends with - specify any suffixes for the input file names to read all the input files
Auto-apply file mask on execution - this allows the user to apply the mask to read multiple files at a time upon executing the module. By default, FALSE(Unchecked).
Skip - By default, FALSE(Unchecked). This option helps to bypass the module from the workflow.
There are no output vista items from his module. Final output gather after concatenation should be defined within the Parameters tab section.
There is no information available for this module.
In this example, we read independent SEGY files by using Input SEG-Y files. In other instance, we read g-Platform internal data files (.gsd) using seismic file mask.
To read them manually, user should click on icon. It will open a new window.
Click inside File path and choose the file path. Here, we can select multiple files by holding SHIFT button. Select all the files and click " Open"
Click OK. With this step, we successfully provided all the input SEG-Y files.
How to use seismic file mask?
we are reading multiple GSD files with different file names as poland-2d-denoise-gathers, poland-2d-scdcn-gathers-for-scamp, poland-2d-scdcn-scamp-gathers etc.,. We read these files as independently and also by using mask.
Seismic file mask is nothing but providing a common file name among all the input files with a combination of special character.
In this case, our input file names are poland-2d-denoise-gathers, poland-2d-scdcn-gathers-for-scamp, poland-2d-scdcn-scamp-gathers
To create a seismic file mask, we simply provide the name as .*poland-2d.*
Place this expression or seismic file mask against the seismic file mask in the Parameters tab.
Now click on "Apply seismic files from mask" action item. It will add all the files(.gsd) associated with the seismic file mask. They'll display in the Input GSD files list.
To check the input file names, click on the table icon. It will open a new window with all the input files.
Apply seismic files from mask - in case the user wants to use seismic file mask, click on this action item and it will apply the mask. This is useful for reading multiple seismic files at a time by using a mask file. It avoids manual selection of the input dataset(s).
YouTube video lesson, click here to open [VIDEO IN PROCESS...]
Yilmaz. O., 1987, Seismic data processing: Society of Exploration Geophysicist
* * * If you have any questions, please send an e-mail to: support@geomage.com * * *
