Segy-change: The swiss army knife for the SEG-Y files

Data collected during active and passive seismic surveys can be stored in many different, more or less standard, formats. One of the most popular is the SEG-Y format, developed since 1975 to store single-line seismic digital data on tapes, and now evolved to store them into hard-disk and other media as well. Unfortunately, sometimes, files that are claimed to be recorded in the SEG-Y format cannot be processed using available free or industrial packages. Aiming to solve this impasse we present segy-change, a pre-processing software program to view, analyze, change and fix errors present in SEG-Y data files. It is written in C language and it can be used also as a software library and is compatible with most operating systems. Segy-change allows the user to display and optionally change the values inside all parts of a SEG-Y file: the file header, the trace headers and the data blocks. In addition, it allows to do a quality check on the data by plotting the traces. We provide instructions and examples on how to use the software.