Load SEG-Y containing traces with varying start times (DELRT)
To load SEG-Y data containing traces with varying start times:
- During loading
- Load the data with a constant start time
- Store the variable start time in a trace header
- After loading, apply a trace shift process to reposition the traces
- Start SEGY Loader.
- Configure and select files as you would normally.
- In the “Specify byte locations of Headers” window:
- At “First Sample Time/Depth” choose Constant, with a value of 0.
- Expand the Advanced Mappings panel.
- Uncheck the “Hide fields with no value” box.
- Choose an unused header, e.g. “laga”
- Enter the byte location for the shift data, usually the DELRT header: 109
- Confirm that the value range is sensible.
- Complete the SEG-Y load and output the dugio volume.
- Open the project
- Add the new volume to the session.
- Create a Trace Shift process
a. Volume: Select the loaded, unshifted volume
b. Shift: Choose “Trace Header” and select the advanced mappings header containing the start time, e.g. laga.
c. Update the output start and end values to include the full length of the shifted traces.