Channel_Data 
Logical Entity Name  Channel_Data 
Default Table Name  Channel_Data 
Definition  Summary information on a channel 

Channel_Data Attributes 
Attribute/Logical Rolename  Domain  Datatype  NULL  Definition 
net(PK)(FK)    VARCHAR(8)  NO  Unique network identifier. This character string is the name of a seismic network 
sta(PK)(FK)    VARCHAR(6)  NO  Station code. This is the common code-name of a seismic observatory. Generally only three or four characters are used 
seedchan(PK)    VARCHAR(3)  NO  SEED channel name. The first character denotes the band code, the second for the instrument code and the third represents the component code 
location(PK)    VARCHAR(2)  NO  Describes the individual sites on an array station, operated by the same network operator 
ondate(PK)(FK)    DATE  NO  This attribute denotes the start date 
channel    VARCHAR(8)  YES  Channel name 
channelsrc    VARCHAR(8)  YES  Domain for channel. This specifies what naming convention is used for the channel name (i.e. SEED, USGS, etc.) 
inid(FK)    NUMERIC(8, 0)  YES  Instrument identifier. It refers to the Generic Abbreviation Dictionary, that contains a name for this instrument 
remark    VARCHAR(30)  YES  An optional comment given to the instrument. It can be anything, including a serial number or a notation of special modifications 
unit_signal(FK)    NUMERIC(8, 0)  NO  A unit lookup key that refers to the Units Abbreviation Dictionary for the signal response of the instrument – usually the ground motion response, or something else for non-seismic devices 
unit_calib(FK)    NUMERIC(8, 0)  NO  A unit lookup key that refers to the Units Abbreviation Dictionary for the units of calibration input, usually volts or amps 
lat    FLOAT  YES  Latitude. This attribute is the geographic latitude. Locations north of the equator have positive latitudes 
lon    FLOAT  YES  Longitude. This attribute is the geographic longitude. Longitudes are measured positive east of the Greenwich meridian 
elev    FLOAT  YES  Elevation. This attribute is the elevation of a seismic station relative to mean sea level 
edepth    FLOAT  YES  Emplacement depth. This attribute gives the depth at which the instrument is positioned, relative to the value of elev 
azimuth    FLOAT  YES  The azimuth of the instrument from north, clockwise 
dip    FLOAT  YES  The dip of the instrument, down from horizontal 
format_id(FK)    NUMERIC(8, 0)  NO  A data format lookup key that refers to the Data Format Dictionary that describes the format of the data in the data section for this channel 
record_length    NUMERIC(8, 0)  YES  The exponent (as a power of two) of the record length for these data 
samprate    FLOAT  NO  Sampling rate. This attribute is the sample rate in samples/second 
clock_drift    FLOAT  YES  A tolerance value, measured in seconds per sample, used as a thresold for time error detection in the data. The number of samples in a record are multiplied by this value to calculate a maximum drift allowed for the time in the next record. If the difference in time is less than this drift, consider them in the same time series 
flags    VARCHAR(27)  YES  Channel flags 
offdate    DATE  YES  This attribute denotes the end date 
lddate    DATE  YES  Load date. Date and time that the record was created or last modified, in Oracle date datatype 

Channel_Data Keys 
Key Name  Key Type  Keys 
ChD00  PrimaryKey  net, sta, seedchan, location, ondate 

Channel_Data Relationships 
Parent Relationships: 
Entity Name  Type  Cardinality  Business Name  VerbPhrase  InversePhrase  Foreign Keys  Is Supertype 
D_Abbreviation  Non-Identifying  Zero or One to Zero or More        inid  NO 
D_Format  Non-Identifying  One To Zero or More        format_id  NO 
D_Unit  Non-Identifying  One To Zero or More        unit_signal  NO 
D_Unit  Non-Identifying  One To Zero or More        unit_calib  NO 
Station_Data  Identifying  One To Zero or More        net, sta, ondate  NO 
Child Relationships: 
Entity Name  Type  Cardinality  Business Name  VerbPhrase  InversePhrase  Foreign Keys  Is Subtype 
Channel_Comment  Identifying  One To Zero or More          NO 
Coefficients  Identifying  One To Zero or More          NO 
Decimation  Identifying  One To Zero or More          NO 
Polynomial  Identifying  One To Zero or More          NO 
Poles_Zeros  Identifying  One To Zero or More          NO 
Sensitivity  Identifying  One To Zero or More          NO 
Simple_Response  Identifying  One To Zero or More          NO 

Channel_Data Check Constraints 
Check Constraint Name  CheckConstraint 
ChD01  azimuth >= 0.0 AND azimuth <= 360.0 
ChD02  clock_drift >= 0.0 
ChD03  dip >= -90.0 AND dip <= 90.0 
ChD04  edepth >= 0.0 
ChD06  lat >= -90.0 AND lat <= 90.0 
ChD07  lon >= -180.0 AND lon <= 180.0 
ChD08  record_length >= 8 AND record_length <= 12 
ChD09  samprate >= 0.0