FDSN Reserved Headers
The “FDSN” key at the root of the Extra Headers are reserved for definition by the FDSN. See A: Extra header examples for an example of FDSN extra headers.
The FDSN reserved headers are defined and documented in JSON Schema.
Download the FDSN Extra Header schema v1.0.
The documentation and schema of these headers may be browsed here:
Extra headers in miniSEED 3 data format
Reserved extra headers defined by the FDSN
No Additional PropertiesHeaders related to data timing and recording system clock
No Additional PropertiesDEPRECATED Timing quality. A vendor specific value from 0 to 100% of maximum accuracy. [same as SEED 2.4 Blockette 1001, field 3] It is recommended to use MaxEstimatedError instead.
Time correction applied to record start time in seconds. [same as SEED 2.4 FSDH, field 16]
Maximum estimated timing error in seconds.
If present, one or more leap seconds occuring during this record. The value specifies the number of leap seconds and direction. For example, use 1 to specify a single positive leap second and -1 to specify a single negative leap second. [incorporates SEED 2.4 FSDH, field 12, bits 4 and 5]
List of timing exceptions
No Additional ItemsEach item of this array must be:
No Additional Properties
Time of timing exeption. [same as SEED 2.4 Blockette 500, field 4]
VCO correction, a percentage from 0 to 100% of VCO control value, where 0 is the slowest and 100 is the fastest. [same as SEED 204 Blockette 500, field 3]
Reception quality as a percent of maximum clock accuracy based only on information from the clock. [same as SEED 2.4 Blockette 500, field 6]
Exception count, with meaning based on type of exception, such as 15 missing time marks. [same as SEED 2.4 Blockette 500, field 7]
Description of clock exception, such as MISSING TIMEMARK. [same as SEED 2.4 Blockette 500, field 8]
Description of clock status, clock specific parameters such as the station for an Omega clock or satellite signal to noise ratios for GPS clocks. [same as SEED 2.4 Blockette 500, field 10]
Headers related to event detection and progression
No Additional PropertiesAn event starts in this record. [same as SEED 2.4 FSDH, field 12, bit 2]
An in-progress event ends in this record, i.e. the detection algorithm de-triggers. [same as SEED 2.4 FSDH, field 12, bit 3]
An event is in progress. [same as SEED 2.4 FSDH, field 12, bit 6]
List of event detections
No Additional ItemsEach item of this array must be:
No Additional Properties
Type of event detection, e.g. MURDOCK
Event amplitude of signal in counts. [same as SEED 2.4 Blockettews 200 and 201, field 3]
Event period of signal in seconds. [same as SEED 2.4 Blockettews 200 and 201, field 4]
Event background estimate in counts. [same as SEED 2.4 Blockettews 200 and 201, field 5]
Event detection wave, use values of DILATATION or COMPRESSION if determined. [same as SEED 2.4 Blockettews 200 and 201, field 6, bit 0]
Units of amplitude band background estimate, use COUNTS for unprocessed signal. [similar to SEED 2.4 Blockettews 200, field 6, bit 1]
Event signal onset time. [same as SEED 2.4 Blockettews 200 and 201, field 8]
Murdock event detection signal-to-noise ratios. [same as SEED 2.4 Blockette 201, field 9]
No Additional ItemsEach item of this array must be:
Murdock event detction lookback value: 0, 1 or 2. [same as SEED 2.4 Blockette 201, field 10]
Murdock event detection pick algorithm: 0 or 1. [same as SEED 2.4 Blockette 201, field 11]
Name of the event detector. [same as SEED 2.4 Blockette 200, field 9 and Blockette 201, field 12]
Headers related to calibrations
No Additional PropertiesList of calibration sequences
No Additional ItemsEach item of this array must be:
List of calibrations
No Additional PropertiesType of calibration: STEP, SINE, PSEUDORANDOM, GENERIC.
Calibration begin time. [similar to SEED 2.4 Blockettes 300,310,320,390, field 3]
Calibration end time. [same as SEED 2.4 Blockette 395, field 3]
Number of step calibrations in sequence. [same as SEED 2.4 Blockette 300, field 4]
Step calibration, first pulse is positive. [same as SEED 2.4 Blockette 300, field 5, bit 0]
Step calibration alternate sign. [same as SEED 2.4 Blockettes 300, field 5, bit 1]
Calibration trigger, use AUTOMATIC or MANUAL. [same as SEED 2.4 Blockettes 300,310,320,390, field 5, bit 2]
Calibration is continued from previous records. [same as SEED 2.4 Blockettes 300,310,320,390, field 5, bit 3]
Amplitude of calibration signal. For pseudo-random calibrations, this should be the peak-to-peak amplitude of the steps. [same as SEED 2.4 Blockettes 300,310, field 8 and Blockettes 320,390, field 7]
Units of calibration input, usually volts or amps. [same as SEED 2.4 Blockette 52, field 9]
Amplitude range of calibration, use values of PEAKTOPEAK, ZEROTOPEAK, RMS OR RANDOM. [same as SEED 2.4 Blockette 310, field 5, bits 4,5,6 and Blockette 320, field 5, bit 4]
Duration of calibration in seconds. For step calibrations this is the duration of the step. [same as SEED 2.4 Blockettes 300,310,320,390, field 6]
Period of sine calibrations in seconds. [same as SEED 2.4 Blockette 310, field 7]
Interval between times a step calibration is on in seconds. [same as SEED 2.4 Blockette 300, field 7]
Channel containing the calibration input. [same as SEED 2.4 Blockettes 300,310, field 9 and Blockettes 320,390, field 8]
Reference amplitude. This is a user-defined value that indicates either the voltage or amperage of the calibration signal when the calibrator is set to 0dB. [same as SEED 2.4 Blockettes 300,310, field 11 and Blockette 320, field 10]
Coupling of the calibration signal, such as RESISTIVE or CAPACITIVE. [same as SEED 2.4 Blockettes 300,310, field 12 and Blockette 320, field 11]
Rolloff characteristics for any filters used on the calibrator, such as 3dB@10Hz. [same as SEED 2.4 Blockettes 300,310, field 13 and Blockette 320, field 12]
Noise characteristics for pseudo-random calibrations, such as WHITE or RED. [same as SEED 2.4 Blockette 320, field 13]
Headers related to sensor recentering (mass, gimble, etc.)
No Additional PropertiesList of recentering sequences
No Additional ItemsEach item of this array must be:
List of recenterings
No Additional PropertiesType of recenter: Mass, Gimbal, etc. If omitted a mass recenter may be assumed.
Recenter begin time.
Estimate of recenter end time.
Calibration trigger, use AUTOMATIC or MANUAL.
No Additional Properties
Sensor mass position is offscale as defined by the vendor or operator.
Amplifier saturation detected. [same as SEED 2.4 FSDH, field 14, bit 0]
Digitizer clipping detected. [same as SEED 2.4 FSDH, field 14, bit 1]
Spikes detected. [same as SEED 2.4 FSDH, field 14, bit 2]
Glitches detected. [same as SEED 2.4 FSDH, field 14, bit 3]
A digital filter may be charging. [same as SEED 2.4 FDSH, field 14, bit 6]
DEPRECATED Station volume parity error possibly present. [same as SEED 2.4 FDSH, field 13, bit 0]
DEPRECATED Long record read (possibly no problem). [same as SEED 2.4 FDSH, field 13, bit 1]
DEPRECATED Short record read (record padded). [same as SEED 2.4 FDSH, field 13, bit 2]
DEPRECATED Start of time series. [same as SEED 2.4 FDSH, field 13, bit 3]
DEPRECATED End of time series. [same as SEED 2.4 FDSH, field 13, bit 4]
DEPRECATED Missing data. [same as SEED 2.4 FDSH, field 14, bit 4]
DEPRECATED Telemetry synchronization error. [same as SEED 2.4 FDSH, field 14, bit 5]
Description of data logger
No Additional PropertiesModel of equipment
Serial number of equipment
An identifier for a provenance description
Data quality indicator, use D, R, Q or M. [same as SEED 2.4 FSDH, field 2]
Data record sequence number. [same as SEED 2.4 FSDH, field 1]
When not present, the boolean values in the FDSN reserved headers should be considered to be false unless otherwise documented. Such values do not need to be included when the value is false.