18.14 SEISEI, splitting and merging SEISAN readable binary files

The program can merge several SEISAN, MiniSEED, SAC etc waveform files to one file or take one SEISAN, GSE or MiniSEED file and split it into single channel files. The program is intended for editing waveform files and merging files from different networks to one file. In order to use SEISEI for merging files, a DIRF must be made to make a filenr.lis file containing the files to be merged. The program will sequentially read filenr.lis and merge files which have start times within the time interval specified (3 minutes default). Once a gap of more than 3 minutes occur, a new output file is made. Merging to a new file can be forced by editing filenr.lis so the groups of files to be merged are separated by a blank line, however, within the group, the time difference can still only be the given time interval.

If two channels to be merged have the same station and channel codes and the same start time, the second occurrence will be ignored. If the station and channel codes are the same, but start time different, the user will be asked to confirm merging.

The program can also split up a multichannel file to files with only one channel. This can be used to remove unwanted channels by deleting selected channels and merging again. When the file is split up, the channel component is added to the file name. A filenr.lis file can also be used for splitting many files in one go. If a file is only to be split into only 2 files, it is more convenient to use the program SEIDEL (only works on SEISAN format), see above. SEISEI is also used in connection with MULPLT for merging files automatically based on waveform file names in an S-file.

Note: The network extension of merged files will be set by default to the value of parameter
MERGE_WAVEFORM in SEISAN.DEF.