Network codes

Network codes are assigned by the FDSN to uniquely identify the owner and operator responsible for the data collected by a network. Network operators may request a network code as needed for new deployments.

Temporary network code convention

Network codes for deployments that are known to be temporary are strongly encouraged to include the 4-digit start year of the deployment at the end of the code with the following pattern:

<1-4 characters><4-digit start year>

For example, SEIS2018 would be a valid network code and imply that the initial deployment was in the year 2018 and is temporary.

Transitional mapping of previously allocated temporary network codes

Historical temporary network codes were allocated as two-character codes, with the first character being a digit (0-9) or the letters X, Y or Z. Many of these codes have been reused for different deployments in different years and are therefore not globally unique. A data owner or delegate data center may wish to convert, or provide an alias, for data using the older, 2-character codes. The mapping from the 2-character codes is strongly recommended to follow this pattern:

<2-character code><4-digit start year>

where the initial character is a digit (0-9) or the letters X, Y or Z.

For example, a network deployment allocated a network code of XA operating in the years 2002 and 2003 could be mapped to XA2002.

A temporary network operator may wish to request a 6 character network code in the transitional mapping pattern above in order have a globally unique code that is also usable with miniSEED 2 through the mapping. Furthermore, the FDSN reserves all 6 character network codes that match the transitional mapping pattern for all previously or future allocated 2 character temporary network codes. Thus the code XA2002 must be assigned solely to the temporary network with code XA that was operating in 2002.

Special network codes

Two network codes are reserved for special cases:

  • SS – This code may be used by any institution running a Single Station, the station should be registered with the International Registry of Seismograph Stations. Care must be taken to ensure that the station code is not the same as another station using the SS network code.

  • XX – This code is not real. It is reserved for test data, examples or transient usage when a real code cannot be used. Data with this network code should never be distributed.