AFFILIATION

Attributes

Attribute	Format	Summary Description	Index
NET	VARCHAR2(6)	Published network name
STA	VARCHAR2(6)	Station code
GROUP_NAME	VARCHAR2(13)	ISC internal group name
GROUP_TYPE	VARCHAR2(12)	ISC internal group type
AUTHOR	VARCHAR2(16)	Code of agency that created parameters
REPORTER	VARCHAR2(16)	Agency that reported parameters to ISC
LDDATE	DATE	Date loaded in ISC database
MODDATE	DATE	Last date modified
REMID	NUMBER(8)	External key to remark table

Notes

The affiliation table stores the network and groups to which each station belongs. Each station belongs to only one network; the network/station code combination is the publicly-known unique identification of a station. Station groups may be used internally at the ISC for a variety of purposes including

Data Collection: a station group may be defined for each agency reporting, and readings from that agency for other stations set aside for examination before being inserted into the ISC database.
Automatic Association: different station groups of stations have different historical patterns for reporting, which can be used to in selecting the most likely earthquake with which a reading should be associated.
Applying Station Corrections: Certain groups of stations may have different time or amplitude corrections that are used in computing earthquake parameters.
Composing Waveform Requests: Stations may be assigned to different groups depending on the data centre from which they are available.