Why do some of my data files include some extra characters or double periods between the network code and channel code in the file name?
In 1998, the DMC began using location identifiers to uniquely identify a data stream among many data streams for the same channel ID and station ID.
EXAMPLE: ANMO.IU.00.BHZ.xxxx and ANMO.IU.10.BHZ.xxxx means there are two different instruments (00 and 10) at the ANMO site that use the BHZ channel designation.
Double periods will result in a filename if a station does not use location identifiers. The file name will look something like this: ANMO.IU..LHN.xxxx, representing the empty designation for a location ID. In SEED, an empty location ID is represented by two SPACE characters. To see if there are location identifiers used for a particular installation, use SeismiQuery’s channel tool and be sure to checkbox the "location" field to include this field in your query.