2. StationXML Reference

2.1. <FDSNStationXML> required

Warning, Future Change

schemaVersion: This attribute may change to be a string to allow micro versions, and potential dash, ‘-’, separators starting in version 2. Users should not assume ‘xs:decimal’.

Root-level for StationXML documents.

Attributes of <FDSNStationXML>:

attribute	type	required	description	example
schemaVersion	decimal	yes	The StationXML schema version of this document.	schemaVersion=”1.2”

Sub Elements of <FDSNStationXML>:

element	type	number
<Source>	string	required
<Sender>	string	optional
<Module>	string	optional
<ModuleURI>	anyURI	optional
<Created>	dateTime	required
<Network>		required, many

2.1.1. <Source> required

FDSNStationXML → Source

Warning, Future Change

<Source>: This element is likely to be a choice with Sender.

content type: string

Originator of the information contained in the document. It is recommended that archives or services providing StationXML that are not the original creator of the metadata set this to be the empty element, especially because a StationXML document may contain information from many unrelated networks.

2.1.2. <Sender>

FDSNStationXML → Sender

Warning, Future Change

<Sender>: This element is likely to be a choice with Source.

content type: string

Name of the institution sending this document, for example the institution hosting an FDSN Station web service. It is recommended that authoritative StationXML created by the originator of the metadata not use Sender and use Source instead. For example metadata created by a network operator for submission to other data archives would only use Source, The data archive in response to a request would use Sender.

2.1.3. <Module>

FDSNStationXML → Module

content type: string

Name of the software module that generated this document.

Example: <Module>SeisComp3</Module>

2.1.4. <ModuleURI>

FDSNStationXML → ModuleURI

content type: anyURI

Resource identifier of the query that generated the document, or, if applicable, the resource identifier of the software that generated this document.

2.1.5. <Created> required

FDSNStationXML → Created

content type: dateTime

Date that this document was generated.

2.2. <Network> required

Warning, Future Change

endDate: This attribute should not be used if it is in the future.

Warning, Future Change

endDate: This attribute is likely to require timezone of Z.

Warning, Future Change

startDate: This attribute is likely to require timezone of Z.

The Network container. All station metadata for this network is contained within this element. A Description element may be included with the official network name and other descriptive information. An Identifier element may be included to designate a persistent identifier (e.g. DOI) to use for citation. A Comment element may be included for additional comments.

An active Network should not use the endDate attribute. Unlike SEED, do not use an endDate in the distant future to mean active.

Example: <Network code=”XX” startDate=”2016-01-27T13:00:00Z” />

Attributes of <Network>:

attribute	type	required	description	example
alternateCode	string	no	A code used for display or association	alternateCode=”GSN”
code	string	yes	Name of Network	code=”XX”
endDate	dateTime	no	End date of network. Do not use if still active, endDate should not be in the future.	endDate=”2018-01-27T00:00:00Z”
historicalCode	string	no	A previously used code if different from the current code	historicalCode=”XX”
restrictedStatus	RestrictedStatusType	no	One of: “open”, “closed”, “partial”	restrictedStatus=”open”
sourceID	anyURI	no	A data source identifier in URI form. It is recommended that this follow the FDSN Source Identifiers specification, http://docs.fdsn.org/projects/source-identifiers	sourceID=”FDSN:XX”
startDate	dateTime	no	Start date of network	startDate=”2016-07-01T00:00:00Z”

Sub Elements of <Network>:

element	type	number
<Description>	string	optional
<Identifier>	string	optional, many
<Comment>		optional, many
<DataAvailability>		optional
<Operator>		optional, many
<TotalNumberStations>	decimal	optional
<SelectedNumberStations>	decimal	optional
<Station>		optional, many

2.2.1. <Description>

Network → Description

content type: string

Description of the Network

Example: <Description>This is a description</Description>

2.2.2. <Identifier>

Network → Identifier

content type: string

A type to document persistent identifiers. Identifier values should be specified without a URI scheme (prefix), instead the identifier type is documented as an attribute.

Example: <identifier type=”DOI”>10.1000/140</identifier>

Example: <identifier type=”DOI”>10.7914/SN/XX</identifier>

Attributes of <Identifier>:

attribute	type	required	description	example
type	string	no	Identifier type	type=”DOI”

2.2.3. <Comment>

Network → Comment

Container for a comment or log entry.

Attributes of <Comment>:

attribute	type	required	description	example
id	CounterType	no	An ID for this comment	id=”12345”
subject	string	no	A subject for this comment. Multiple comments with the same subject should be considered related.	subject=”Scheduled maintenance”

Sub Elements of <Comment>:

element	type	number
<Value>	string	required
<BeginEffectiveTime>	dateTime	optional
<EndEffectiveTime>	dateTime	optional
<Author>		optional, many

<Value> required

Network → Comment → Value

content type: string

Comment text.

Example: <Value>Temporary network deployment</Value>

<BeginEffectiveTime>

Network → Comment → BeginEffectiveTime

content type: dateTime

Start time for when comment applies.

Example: <BeginEffectiveTime>2008-09-15T00:00:00Z</BeginEffectiveTime>

<EndEffectiveTime>

Network → Comment → EndEffectiveTime

content type: dateTime

End time for when comment applies.

Example: <EndEffectiveTime>2008-09-16T12:00:00Z</EndEffectiveTime>

<Author>

Network → Comment → Author

Author of Comment.

Person’s contact information. A person can belong to multiple agencies and have multiple email addresses and phone numbers.

Sub Elements of <Author>:

element	type	number
<Name>	string	optional, many
<Agency>	string	optional, many
<Email>	string	optional, many
<Phone>		optional, many

<Name>

Network → Comment → Author → Name

content type: string

Name of contact or author

Example: <Name>Dr. Jane Doe</Name>

<Agency>

Network → Comment → Author → Agency

content type: string

Agency of contact or author

Example: <Agency>USGS</Agency>

<Email>

Network → Comment → Author → Email

content type: string

Email of contact or author

Example: <Email>jane_doe@example.com</Email>

<Phone>

Network → Comment → Author → Phone

Phone of contact or author

Attributes of <Phone>:

attribute	type	required	description	example
description	string	no

Sub Elements of <Phone>:

element	type	number
<CountryCode>	integer	optional
<AreaCode>	integer	required
<PhoneNumber>	string	required

<CountryCode>

Network → Comment → Author → Phone → CountryCode

content type: integer

Telephone country code

Example: <CountryCode>64</CountryCode>

<AreaCode> required

Network → Comment → Author → Phone → AreaCode

content type: integer

Telephone area code

Example: <AreaCode>408</AreaCode>

<PhoneNumber> required

Network → Comment → Author → Phone → PhoneNumber

content type: string

Telephone number

Example: <PhoneNumber>5551212</PhoneNumber>

2.2.4. <DataAvailability>

Network → DataAvailability

A description of time series data availability. This information should be considered transient and is primarily useful as a guide for generating time series data requests. The information for a DataAvailability:Span may be specific to the time range used in a request that resulted in the document or limited to the availability of data within the request range. These details may or may not be retained when synchronizing metadata between data centers.

A type for describing data availability.

Sub Elements of <DataAvailability>:

element	type	number
<Extent>		optional
<Span>		optional, many

<Extent>

Network → DataAvailability → Extent

Data availability extents, the earliest and latest data available. No information about the continuity of the data is included or implied.

Attributes of <Extent>:

attribute	type	required	description	example
end	dateTime	yes	end date of extent	end=”1988-12-31T00:00:00Z”
start	dateTime	yes	start date of extent	start=”1988-01-01T00:00:00Z”

<Span>

Network → DataAvailability → Span

A type for describing data availability spans, with variable continuity. The time range described may be based on the request parameters that generated the document and not necessarily relate to continuity outside of the range. It may also be a smaller time window than the request depending on the data characteristics.

Attributes of <Span>:

attribute	type	required	description	example
end	dateTime	yes	end date of span	end=”1988-12-31T00:00:00Z”
maximumTimeTear	decimal	no	The maximum time tear (gap or overlap) in seconds between time series segments in the specified range.	maximumTimeTear=”0.01”
numberSegments	integer	yes	The number of continuous time series segments contained in the specified time range. A value of 1 indicates that the time series is continuous from start to end.	numberSegments=”2”
start	dateTime	yes	start date of span	start=”1988-01-01T00:00:00Z”

2.2.5. <Operator>

Network → Operator

Agency and contact persons who manage this network.

Since the Contact element is a generic type that represents any contact person, it also has its own optional Agency element. It is expected that typically the contact’s optional Agency tag will match the Operator Agency. Only contacts appropriate for the enclosing element should be included in the Operator tag.

Sub Elements of <Operator>:

element	type	number
<Agency>	string	required
<Contact>		optional, many
<WebSite>	anyURI	optional

<Agency> required

Network → Operator → Agency

content type: string

The operating agency.

Example: <Agency>USGS</Agency>

<Contact>

Network → Operator → Contact

Person’s contact information. A person can belong to multiple agencies and have multiple email addresses and phone numbers.

Sub Elements of <Contact>:

element	type	number
<Name>	string	optional, many
<Agency>	string	optional, many
<Email>	string	optional, many
<Phone>		optional, many

<Name>

Network → Operator → Contact → Name

content type: string

Name of contact or author

Example: <Name>Dr. Jane Doe</Name>

<Agency>

Network → Operator → Contact → Agency

content type: string

Agency of contact or author

Example: <Agency>USGS</Agency>

<Email>

Network → Operator → Contact → Email

content type: string

Email of contact or author

Example: <Email>jane_doe@example.com</Email>

<Phone>

Network → Operator → Contact → Phone

Phone of contact or author

Attributes of <Phone>:

attribute	type	required	description	example
description	string	no

Sub Elements of <Phone>:

element	type	number
<CountryCode>	integer	optional
<AreaCode>	integer	required
<PhoneNumber>	string	required

<CountryCode>

Network → Operator → Contact → Phone → CountryCode

content type: integer

Telephone country code

Example: <CountryCode>64</CountryCode>

<AreaCode> required

Network → Operator → Contact → Phone → AreaCode

content type: integer

Telephone area code

Example: <AreaCode>408</AreaCode>

<PhoneNumber> required

Network → Operator → Contact → Phone → PhoneNumber

content type: string

Telephone number

Example: <PhoneNumber>5551212</PhoneNumber>

<WebSite>

Network → Operator → WebSite

content type: anyURI

Website of operating agency

Example: <WebSite>http://usgs.gov</WebSite>

2.2.6. <TotalNumberStations>

Network → TotalNumberStations

Warning, Future Change

<TotalNumberStations>: This element is likely to be removed.

content type: decimal

range: TotalNumberStations \(\ge\) 0

The total number of stations in this network, including inactive or terminated stations.

Example: <TotalNumberStations>24</TotalNumberStations>

2.2.7. <SelectedNumberStations>

Network → SelectedNumberStations

Warning, Future Change

<SelectedNumberStations>: This element is likely to be removed.

content type: decimal

range: SelectedNumberStations \(\ge\) 0

The number of stations selected in the request that resulted in this document.

Example: <SelectedNumberStations>12</SelectedNumberStations>

2.3. <Station>

Warning, Future Change

endDate: This attribute should not be used if it is in the future.

Warning, Future Change

endDate: This attribute is likely to require timezone of Z.

Warning, Future Change

startDate: This attribute is likely to require timezone of Z.

The Station container. All channel metadata for this station is contained within this element. A Description element may be included with the official station name and other descriptive information. An Identifier element may be included to designate a persistent identifier (e.g. DOI) to use for citation or reference. A Comment element may be included for additional comments.

An active Station should not use the endDate attribute. Unlike SEED, do not use an endDate in the distant future to mean active.

Attributes of <Station>:

attribute	type	required	description	example
alternateCode	string	no	A code used for display or association	alternateCode=”ALQ”
code	string	yes	Name of Station	code=”ABCD”
endDate	dateTime	no	End date of station epoch. Do not use if still active, endDate should not be in the future.	endDate=”2018-01-27T00:00:00Z”
historicalCode	string	no	A previously used code if different from the current code	historicalCode=”albq”
restrictedStatus	RestrictedStatusType	no	One of: “open”, “closed”, “partial”	restrictedStatus=”open”
sourceID	anyURI	no	A data source identifier in URI form. It is recommended that this follow the FDSN Source Identifiers specification, http://docs.fdsn.org/projects/source-identifiers	sourceID=”FDSN:XX_ABCD”
startDate	dateTime	no	Start date of station epoch	startDate=”2016-07-01T00:00:00Z”

Sub Elements of <Station>:

element	type	number
<Description>	string	optional
<Identifier>	string	optional, many
<Comment>		optional, many
<DataAvailability>		optional
<Latitude>	double	required
<Longitude>	double	required
<Elevation>	double	required
<Site>		required
<WaterLevel>	double	optional
<Vault>	string	optional
<Geology>	string	optional
<Equipment>		optional, many
<Operator>		optional, many
<CreationDate>	dateTime	optional
<TerminationDate>	dateTime	optional
<TotalNumberChannels>	decimal	optional
<SelectedNumberChannels>	decimal	optional
<ExternalReference>		optional, many
<Channel>		optional, many

2.3.1. <Description>

Station → Description

content type: string

Description of the Station

Example: <Description>This is a description</Description>

2.3.2. <Identifier>

Station → Identifier

content type: string

A type to document persistent identifiers. Identifier values should be specified without a URI scheme (prefix), instead the identifier type is documented as an attribute.

Example: <identifier type=”DOI”>10.1000/140</identifier>

Example: <identifier type=”DOI”>10.5555/12345678</identifier>ABCD.

Attributes of <Identifier>:

attribute	type	required	description	example
type	string	no	Identifier type	type=”DOI”

2.3.3. <Comment>

Station → Comment

Container for a comment or log entry.

Attributes of <Comment>:

attribute	type	required	description	example
id	CounterType	no	An ID for this comment	id=”12345”
subject	string	no	A subject for this comment. Multiple comments with the same subject should be considered related.	subject=”Scheduled maintenance”

Sub Elements of <Comment>:

element	type	number
<Value>	string	required
<BeginEffectiveTime>	dateTime	optional
<EndEffectiveTime>	dateTime	optional
<Author>		optional, many

<Value> required

Station → Comment → Value

content type: string

Comment text.

Example: <Value>GPS Clock is unlocked</Value>

<BeginEffectiveTime>

Station → Comment → BeginEffectiveTime

content type: dateTime

Start time for when comment applies.

Example: <BeginEffectiveTime>2008-09-15T00:00:00Z</BeginEffectiveTime>

<EndEffectiveTime>

Station → Comment → EndEffectiveTime

content type: dateTime

End time for when comment applies.

Example: <EndEffectiveTime>2008-09-16T12:00:00Z</EndEffectiveTime>

<Author>

Station → Comment → Author

Author of Comment.

Person’s contact information. A person can belong to multiple agencies and have multiple email addresses and phone numbers.

Sub Elements of <Author>:

element	type	number
<Name>	string	optional, many
<Agency>	string	optional, many
<Email>	string	optional, many
<Phone>		optional, many

<Name>

Station → Comment → Author → Name

content type: string

Name of contact or author

Example: <Name>Dr. Jane Doe</Name>

<Agency>

Station → Comment → Author → Agency

content type: string

Agency of contact or author

Example: <Agency>USGS</Agency>

<Email>

Station → Comment → Author → Email

content type: string

Email of contact or author

Example: <Email>jane_doe@example.com</Email>

<Phone>

Station → Comment → Author → Phone

Phone of contact or author

Attributes of <Phone>:

attribute	type	required	description	example
description	string	no

Sub Elements of <Phone>:

element	type	number
<CountryCode>	integer	optional
<AreaCode>	integer	required
<PhoneNumber>	string	required

<CountryCode>

Station → Comment → Author → Phone → CountryCode

content type: integer

Telephone country code

Example: <CountryCode>64</CountryCode>

<AreaCode> required

Station → Comment → Author → Phone → AreaCode

content type: integer

Telephone area code

Example: <AreaCode>408</AreaCode>

<PhoneNumber> required

Station → Comment → Author → Phone → PhoneNumber

content type: string

Telephone number

Example: <PhoneNumber>5551212</PhoneNumber>

2.3.4. <DataAvailability>

Station → DataAvailability

A description of time series data availability. This information should be considered transient and is primarily useful as a guide for generating time series data requests. The information for a DataAvailability:Span may be specific to the time range used in a request that resulted in the document or limited to the availability of data within the request range. These details may or may not be retained when synchronizing metadata between data centers.

A type for describing data availability.

Sub Elements of <DataAvailability>:

element	type	number
<Extent>		optional
<Span>		optional, many

<Extent>

Station → DataAvailability → Extent

Data availability extents, the earliest and latest data available. No information about the continuity of the data is included or implied.

Attributes of <Extent>:

attribute	type	required	description	example
end	dateTime	yes	end date of extent	end=”1988-12-31T00:00:00Z”
start	dateTime	yes	start date of extent	start=”1988-01-01T00:00:00Z”

<Span>

Station → DataAvailability → Span

A type for describing data availability spans, with variable continuity. The time range described may be based on the request parameters that generated the document and not necessarily relate to continuity outside of the range. It may also be a smaller time window than the request depending on the data characteristics.

Attributes of <Span>:

attribute	type	required	description	example
end	dateTime	yes	end date of span	end=”1988-12-31T00:00:00Z”
maximumTimeTear	decimal	no	The maximum time tear (gap or overlap) in seconds between time series segments in the specified range.	maximumTimeTear=”0.01”
numberSegments	integer	yes	The number of continuous time series segments contained in the specified time range. A value of 1 indicates that the time series is continuous from start to end.	numberSegments=”2”
start	dateTime	yes	start date of span	start=”1988-01-01T00:00:00Z”

2.3.5. <Latitude> required

Station → Latitude

content type: double

range: -90.0 \(\le\) Latitude \(\lt\) 90.0

Station latitude, in degrees. Where the bulk of the equipment is located (or another appropriate site location). The unit is fixed to be degrees, and datum defaults to WGS84.

Latitude type extending the base type to add datum as an attribute with default.

Example: <Latitude>34.9459</Latitude>

Attributes of <Latitude>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
datum	NMTOKEN	no

2.3.6. <Longitude> required

Station → Longitude

content type: double

range: -180.0 \(\le\) Longitude \(\le\) 180.0

Station longitude, in degrees. Where the bulk of the equipment is located (or another appropriate site location). The unit is fixed to be degrees, and datum defaults to WGS84.

Longitude type extending the base type to add datum as an attribute with default.

Example: <Longitude>-106.4572</Longitude>

Attributes of <Longitude>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
datum	NMTOKEN	no

2.3.7. <Elevation> required

Station → Elevation

content type: double

Elevation of local ground surface level at station, in meters.

Example: <Elevation>1850.0</Elevation>

Attributes of <Elevation>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be METERS, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.3.8. <Site> required

Station → Site

Description of a location using name and optional geopolitical boundaries (country, city, etc.).

Sub Elements of <Site>:

element	type	number
<Name>	string	required
<Description>	string	optional
<Town>	string	optional
<County>	string	optional
<Region>	string	optional
<Country>	string	optional

<Name> required

Station → Site → Name

content type: string

Name of the site

Example: <Name>Albuquerque, New Mexico</Name>

<Description>

Station → Site → Description

content type: string

A longer description of the location of this station

Example: <Description>NW corner of Yellowstone National Park</Description>

<Town>

Station → Site → Town

content type: string

The town or city closest to the station.

Example: <Town>Albuquerque</Town>

<County>

Station → Site → County

content type: string

The county where the station is located

Example: <County>Bernalillo</County>

<Region>

Station → Site → Region

content type: string

The state, province, or region of this site.

Example: <Region>Southwest U.S.</Region>

<Country>

Station → Site → Country

content type: string

The country of this site.

Example: <Country>U.S.A.</Country>

2.3.9. <WaterLevel>

Station → WaterLevel

content type: double

Elevation of the water surface in meters for underwater sites, where 0 is mean sea level. If you put an OBS on a lake bottom, where the lake surface is at elevation=1200 meters, then you should set WaterLevel=1200. An OBS in the ocean would have WaterLevel=0.

Example: <WaterLevel>1200</WaterLevel>

Attributes of <WaterLevel>:

attribute	type	required	description	example
unit	string	no	The unit of measurement. Use SI unit names and symbols whenever possible (e.g., ‘m’ instead of ‘METERS’).	unit=”m”
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.3.10. <Vault>

Station → Vault

content type: string

Type of vault, e.g. World-Wide Standardized Seismograph Network (WWSSN), tunnel, USArray Transportable Array Generation 2, etc.

2.3.11. <Geology>

Station → Geology

content type: string

Type of rock and/or geologic formation at the station.

2.3.12. <Equipment>

Station → Equipment

Equipment used by all channels at a station, Equipment that contributes to or affects the response of a channel should be documented on the channel.

A type for equipment related to data acquisition or processing.

Attributes of <Equipment>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information or be derived from the same base instruments.

Sub Elements of <Equipment>:

element	type	number
<Type>	string	optional
<Description>	string	optional
<Manufacturer>	string	optional
<Vendor>	string	optional
<Model>	string	optional
<SerialNumber>	string	optional
<InstallationDate>	dateTime	optional
<RemovalDate>	dateTime	optional
<CalibrationDate>	dateTime	optional, many

<Type>

Station → Equipment → Type

content type: string

Type of equipment

<Description>

Station → Equipment → Description

content type: string

Description of equipment

<Manufacturer>

Station → Equipment → Manufacturer

content type: string

Manufacturer of equipment

<Vendor>

Station → Equipment → Vendor

content type: string

Vendor of equipment

<Model>

Station → Equipment → Model

content type: string

Model of equipment

<SerialNumber>

Station → Equipment → SerialNumber

content type: string

Serial number of equipment

<InstallationDate>

Station → Equipment → InstallationDate

content type: dateTime

Date this equipment was installed

<RemovalDate>

Station → Equipment → RemovalDate

content type: dateTime

Date this equipment was removed

<CalibrationDate>

Station → Equipment → CalibrationDate

content type: dateTime

Date this equipment was calibrated

2.3.13. <Operator>

Station → Operator

Agency who manage this station. Only use if this differs from the Operator of the Network.

Since the Contact element is a generic type that represents any contact person, it also has its own optional Agency element. It is expected that typically the contact’s optional Agency tag will match the Operator Agency. Only contacts appropriate for the enclosing element should be included in the Operator tag.

Sub Elements of <Operator>:

element	type	number
<Agency>	string	required
<Contact>		optional, many
<WebSite>	anyURI	optional

<Agency> required

Station → Operator → Agency

content type: string

The operating agency.

Example: <Agency>USGS</Agency>

<Contact>

Station → Operator → Contact

Person’s contact information. A person can belong to multiple agencies and have multiple email addresses and phone numbers.

Sub Elements of <Contact>:

element	type	number
<Name>	string	optional, many
<Agency>	string	optional, many
<Email>	string	optional, many
<Phone>		optional, many

<Name>

Station → Operator → Contact → Name

content type: string

Name of contact or author

Example: <Name>Dr. Jane Doe</Name>

<Agency>

Station → Operator → Contact → Agency

content type: string

Agency of contact or author

Example: <Agency>USGS</Agency>

<Email>

Station → Operator → Contact → Email

content type: string

Email of contact or author

Example: <Email>jane_doe@example.com</Email>

<Phone>

Station → Operator → Contact → Phone

Phone of contact or author

Attributes of <Phone>:

attribute	type	required	description	example
description	string	no

Sub Elements of <Phone>:

element	type	number
<CountryCode>	integer	optional
<AreaCode>	integer	required
<PhoneNumber>	string	required

<CountryCode>

Station → Operator → Contact → Phone → CountryCode

content type: integer

Telephone country code

Example: <CountryCode>64</CountryCode>

<AreaCode> required

Station → Operator → Contact → Phone → AreaCode

content type: integer

Telephone area code

Example: <AreaCode>408</AreaCode>

<PhoneNumber> required

Station → Operator → Contact → Phone → PhoneNumber

content type: string

Telephone number

Example: <PhoneNumber>5551212</PhoneNumber>

<WebSite>

Station → Operator → WebSite

content type: anyURI

Website of operating agency

Example: <WebSite>http://usgs.gov</WebSite>

2.3.14. <CreationDate>

Station → CreationDate

Warning, Future Change

<CreationDate>: This element is likely to be removed.

content type: dateTime

Date and time (UTC) when the station was first installed.

2.3.15. <TerminationDate>

Station → TerminationDate

Warning, Future Change

<TerminationDate>: This element is likely to be removed.

content type: dateTime

Date and time (UTC) when the station was terminated or will be terminated. Do not include this element if a termination date is not available or is not relevant.

2.3.16. <TotalNumberChannels>

Station → TotalNumberChannels

Warning, Future Change

<TotalNumberChannels>: This element is likely to be removed.

content type: decimal

range: TotalNumberChannels \(\ge\) 0

Total number of channels recorded at this station.

2.3.17. <SelectedNumberChannels>

Station → SelectedNumberChannels

Warning, Future Change

<SelectedNumberChannels>: This element is likely to be removed.

content type: decimal

range: SelectedNumberChannels \(\ge\) 0

The number of channels selected in the request that resulted in this document.

2.3.18. <ExternalReference>

Station → ExternalReference

URI of any type of external report

This type contains a Uniform Resource Identifier (URI) and description for external information that users may want to reference.

Sub Elements of <ExternalReference>:

element	type	number
<URI>	anyURI	required
<Description>	string	required

<URI> required

Station → ExternalReference → URI

content type: anyURI

URI of the external reference.

<Description> required

Station → ExternalReference → Description

content type: string

Description of the external reference.

2.4. <Channel>

Warning, Future Change

endDate: This attribute should not be used if it is in the future.

Warning, Future Change

endDate: This attribute is likely to require timezone of Z.

Warning, Future Change

startDate: This attribute is likely to require timezone of Z.

The Channel container. A Description element may be included with other information. An Identifier element may be included to designate a persistent identifier (e.g. DOI) to use for citation or reference. A Comment element may be included for arbitrary comments.

An active Channel should not use the endDate attribute. Unlike SEED, do not use an endDate in the distant future to mean active.

Attributes of <Channel>:

attribute	type	required	description	example
alternateCode	string	no	A code used for display or association	alternateCode=”Z”
code	string	yes	Name of Channel	code=”BHZ”
endDate	dateTime	no	End date of channel epoch. Do not use if still active, endDate should not be in the future.	endDate=”2018-01-27T00:00:00Z”
historicalCode	string	no	A previously used code if different from the current code	historicalCode=”bhz”
locationCode	string	yes	The locationCode is typically used to group channels from a common sensor. For example, the channels of the primary sensor at global IDA-IRIS stations have locationCode = “00”: 00_BHZ, 00_BHE, 00_BHN, 00_LHZ, …, etc. Even though it is required, locationCode may be, and often is, an empty string, however, it is recommended that the locationCode not be empty.	locationCode=”30”
restrictedStatus	RestrictedStatusType	no	One of: “open”, “closed”, “partial”	restrictedStatus=”open”
sourceID	anyURI	no	A data source identifier in URI form. It is recommended that this follow the FDSN Source Identifiers specification, http://docs.fdsn.org/projects/source-identifiers	sourceID=”FDSN:XX_ABCD_00_B_H_Z”
startDate	dateTime	no	Start date of channel epoch	startDate=”2016-07-01T00:00:00Z”

Sub Elements of <Channel>:

element	type	number
<Description>	string	optional
<Identifier>	string	optional, many
<Comment>		optional, many
<DataAvailability>		optional
<ExternalReference>		optional, many
<Latitude>	double	required
<Longitude>	double	required
<Elevation>	double	required
<Depth>	double	required
<Azimuth>	double	optional
<Dip>	double	optional
<WaterLevel>	double	optional
<Type>	string	optional, many
<SampleRate>	double	optional
<SampleRateRatio>		optional
<ClockDrift>	double	optional
<CalibrationUnits>		optional
<Sensor>		optional
<PreAmplifier>		optional
<DataLogger>		optional
<Equipment>		optional, many
<Response>		optional

2.4.1. <Description>

Channel → Description

content type: string

Description of the Channel

Example: <Description>This is a description</Description>

2.4.2. <Identifier>

Channel → Identifier

content type: string

A type to document persistent identifiers. Identifier values should be specified without a URI scheme (prefix), instead the identifier type is documented as an attribute.

Example: <identifier type=”DOI”>10.1000/140</identifier>

Example: <identifier type=”DOI”>10.5555/12345678</identifier>BHZ.

Attributes of <Identifier>:

attribute	type	required	description	example
type	string	no	Identifier type	type=”DOI”

2.4.3. <Comment>

Channel → Comment

Container for a comment or log entry.

Attributes of <Comment>:

attribute	type	required	description	example
id	CounterType	no	An ID for this comment	id=”12345”
subject	string	no	A subject for this comment. Multiple comments with the same subject should be considered related.	subject=”Scheduled maintenance”

Sub Elements of <Comment>:

element	type	number
<Value>	string	required
<BeginEffectiveTime>	dateTime	optional
<EndEffectiveTime>	dateTime	optional
<Author>		optional, many

<Value> required

Channel → Comment → Value

content type: string

Comment text.

Example: <Value>Large number of spikes</Value>

<BeginEffectiveTime>

Channel → Comment → BeginEffectiveTime

content type: dateTime

Start time for when comment applies.

Example: <BeginEffectiveTime>2008-09-15T00:00:00Z</BeginEffectiveTime>

<EndEffectiveTime>

Channel → Comment → EndEffectiveTime

content type: dateTime

End time for when comment applies.

Example: <EndEffectiveTime>2008-09-16T12:00:00Z</EndEffectiveTime>

<Author>

Channel → Comment → Author

Author of Comment.

Person’s contact information. A person can belong to multiple agencies and have multiple email addresses and phone numbers.

Sub Elements of <Author>:

element	type	number
<Name>	string	optional, many
<Agency>	string	optional, many
<Email>	string	optional, many
<Phone>		optional, many

<Name>

Channel → Comment → Author → Name

content type: string

Name of contact or author

Example: <Name>Dr. Jane Doe</Name>

<Agency>

Channel → Comment → Author → Agency

content type: string

Agency of contact or author

Example: <Agency>USGS</Agency>

<Email>

Channel → Comment → Author → Email

content type: string

Email of contact or author

Example: <Email>jane_doe@example.com</Email>

<Phone>

Channel → Comment → Author → Phone

Phone of contact or author

Attributes of <Phone>:

attribute	type	required	description	example
description	string	no

Sub Elements of <Phone>:

element	type	number
<CountryCode>	integer	optional
<AreaCode>	integer	required
<PhoneNumber>	string	required

<CountryCode>

Channel → Comment → Author → Phone → CountryCode

content type: integer

Telephone country code

Example: <CountryCode>64</CountryCode>

<AreaCode> required

Channel → Comment → Author → Phone → AreaCode

content type: integer

Telephone area code

Example: <AreaCode>408</AreaCode>

<PhoneNumber> required

Channel → Comment → Author → Phone → PhoneNumber

content type: string

Telephone number

Example: <PhoneNumber>5551212</PhoneNumber>

2.4.4. <DataAvailability>

Channel → DataAvailability

A description of time series data availability. This information should be considered transient and is primarily useful as a guide for generating time series data requests. The information for a DataAvailability:Span may be specific to the time range used in a request that resulted in the document or limited to the availability of data within the request range. These details may or may not be retained when synchronizing metadata between data centers.

A type for describing data availability.

Sub Elements of <DataAvailability>:

element	type	number
<Extent>		optional
<Span>		optional, many

<Extent>

Channel → DataAvailability → Extent

Data availability extents, the earliest and latest data available. No information about the continuity of the data is included or implied.

Attributes of <Extent>:

attribute	type	required	description	example
end	dateTime	yes	end date of extent	end=”1988-12-31T00:00:00Z”
start	dateTime	yes	start date of extent	start=”1988-01-01T00:00:00Z”

<Span>

Channel → DataAvailability → Span

A type for describing data availability spans, with variable continuity. The time range described may be based on the request parameters that generated the document and not necessarily relate to continuity outside of the range. It may also be a smaller time window than the request depending on the data characteristics.

Attributes of <Span>:

attribute	type	required	description	example
end	dateTime	yes	end date of span	end=”1988-12-31T00:00:00Z”
maximumTimeTear	decimal	no	The maximum time tear (gap or overlap) in seconds between time series segments in the specified range.	maximumTimeTear=”0.01”
numberSegments	integer	yes	The number of continuous time series segments contained in the specified time range. A value of 1 indicates that the time series is continuous from start to end.	numberSegments=”2”
start	dateTime	yes	start date of span	start=”1988-01-01T00:00:00Z”

2.4.5. <ExternalReference>

Channel → ExternalReference

URI of any type of external report, such as data quality reports.

This type contains a Uniform Resource Identifier (URI) and description for external information that users may want to reference.

Sub Elements of <ExternalReference>:

element	type	number
<URI>	anyURI	required
<Description>	string	required

<URI> required

Channel → ExternalReference → URI

content type: anyURI

URI of the external reference.

<Description> required

Channel → ExternalReference → Description

content type: string

Description of the external reference.

2.4.6. <Latitude> required

Channel → Latitude

content type: double

range: -90.0 \(\le\) Latitude \(\lt\) 90.0

Latitude of this channel’s sensor, in degrees. Often the same as the station latitude, but when different the channel latitude is the true location of the sensor.

Latitude type extending the base type to add datum as an attribute with default.

Example: <Latitude>34.9459</Latitude>

Attributes of <Latitude>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
datum	NMTOKEN	no

2.4.7. <Longitude> required

Channel → Longitude

content type: double

range: -180.0 \(\le\) Longitude \(\le\) 180.0

Longitude of this channel’s sensor, in degrees. Often the same as the station longitude, but when different the channel longitude is the true location of the sensor.

Longitude type extending the base type to add datum as an attribute with default.

Example: <Longitude>-106.4572</Longitude>

Attributes of <Longitude>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
datum	NMTOKEN	no

2.4.8. <Elevation> required

Channel → Elevation

content type: double

Elevation of the sensor, in meters. To find the local ground surface level, add the Depth value to this elevation.

Attributes of <Elevation>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be METERS, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.9. <Depth> required

Channel → Depth

content type: double

The depth of the sensor relative to the local ground surface level, in meters.

Attributes of <Depth>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be METERS, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.10. <Azimuth>

Channel → Azimuth

content type: double

range: 0.0 \(\le\) Azimuth \(\lt\) 360.0

Azimuth of the component in degrees clockwise from geographic (true) north.

Attributes of <Azimuth>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.11. <Dip>

Channel → Dip

content type: double

range: -90.0 \(\le\) Dip \(\le\) 90.0

Dip of the component in degrees, positive is down from horizontal. For horizontal dip=0, for vertical upwards dip=-90 and for vertical downwards dip=+90.

Attributes of <Dip>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.12. <WaterLevel>

Channel → WaterLevel

content type: double

Elevation of the water surface in meters for underwater sites, where 0 is mean sea level. If you put an OBS on a lake bottom, where the lake surface is at elevation=1200 meters, then you should set WaterLevel=1200. An OBS in the ocean would have WaterLevel=0.

Attributes of <WaterLevel>:

attribute	type	required	description	example
unit	string	no	The unit of measurement. Use SI unit names and symbols whenever possible (e.g., ‘m’ instead of ‘METERS’).	unit=”m”
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.13. <Type>

Channel → Type

Warning, Future Change

<Type>: This element is likely to be removed.

content type: string

Data type for this channel. One or more <Type> tags can be used to specify the nature of the data this channel collects. The value between the <Type> tags must be one of: TRIGGERED, CONTINUOUS, HEALTH, GEOPHYSICAL, WEATHER, FLAG or SYNTHESIZED.

This element existed primarily to hold the corresponding value from SEED, but should not be used for new StationXML.

Example: <Type>CONTINUOUS</Type>

2.4.14. <SampleRate>

Channel → SampleRate

content type: double

Sample rate in samples per second. SampleRate is optional unless SampleRateRatio is present, in which case SampleRate is required.

Example: <SampleRate>40.0</SampleRate>

Attributes of <SampleRate>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be SAMPLES/S, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.15. <SampleRateRatio>

Channel → SampleRateRatio

Sample rate expressed as number of samples in a number of seconds. If present, then <SampleRate> must also be present. It can be useful for very slow data (e.g., less than a few samples per day), since it allows for greater precision in the stored value.

Example:

<SampleRate>0.000023148</SampleRate>
              <SampleRateRatio>
                <NumberSamples>2</NumberSamples>
                <NumberSeconds>86400</NumberSeconds>
              </SampleRateRatio>

Sub Elements of <SampleRateRatio>:

element	type	number
<NumberSamples>	integer	required
<NumberSeconds>	integer	required

<NumberSamples> required

Channel → SampleRateRatio → NumberSamples

content type: integer

Integer number of samples that span a number of seconds.

<NumberSeconds> required

Channel → SampleRateRatio → NumberSeconds

content type: integer

Integer number of seconds that span a number of samples.

2.4.16. <ClockDrift>

Channel → ClockDrift

content type: double

range: ClockDrift \(\ge\) 0.0

Tolerance value, measured in seconds per sample, used as a threshold for time error detection in data from the channel.

Attributes of <ClockDrift>:

attribute	type	required	description	example
unit	string	no	The unit of drift value. This value is fixed to be SECONDS/SAMPLE, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

2.4.17. <CalibrationUnits>

Channel → CalibrationUnits

Units of calibration (e.g., V (for Volts) or A (for amps))

Use SI units when possible

A type to document units; use SI whenever possible.

Example:

<CalibrationUnits>
  <Name>V</Name>
  <Description>Volts</Description>
</CalibrationUnits>

Sub Elements of <CalibrationUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Channel → CalibrationUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Channel → CalibrationUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

2.4.18. <Sensor>

Channel → Sensor

Details of the (typically analog) sensor attached to this channel. If this was entered at the Station level, it is not necessary to do it for each Channel, unless you have differences in equipment.

A type for equipment related to data acquisition or processing.

Attributes of <Sensor>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information or be derived from the same base instruments.

Sub Elements of <Sensor>:

element	type	number
<Type>	string	optional
<Description>	string	optional
<Manufacturer>	string	optional
<Vendor>	string	optional
<Model>	string	optional
<SerialNumber>	string	optional
<InstallationDate>	dateTime	optional
<RemovalDate>	dateTime	optional
<CalibrationDate>	dateTime	optional, many

<Type>

Channel → Sensor → Type

content type: string

Type of equipment

<Description>

Channel → Sensor → Description

content type: string

Description of equipment

<Manufacturer>

Channel → Sensor → Manufacturer

content type: string

Manufacturer of equipment

<Vendor>

Channel → Sensor → Vendor

content type: string

Vendor of equipment

<Model>

Channel → Sensor → Model

content type: string

Model of equipment

<SerialNumber>

Channel → Sensor → SerialNumber

content type: string

Serial number of equipment

<InstallationDate>

Channel → Sensor → InstallationDate

content type: dateTime

Date this equipment was installed

<RemovalDate>

Channel → Sensor → RemovalDate

content type: dateTime

Date this equipment was removed

<CalibrationDate>

Channel → Sensor → CalibrationDate

content type: dateTime

Date this equipment was calibrated

2.4.19. <PreAmplifier>

Channel → PreAmplifier

Preamplifier (if any) used by this channel. If this was entered at the Station level, it is not necessary to do it for each Channel, unless you have differences in equipment.

A type for equipment related to data acquisition or processing.

Attributes of <PreAmplifier>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information or be derived from the same base instruments.

Sub Elements of <PreAmplifier>:

element	type	number
<Type>	string	optional
<Description>	string	optional
<Manufacturer>	string	optional
<Vendor>	string	optional
<Model>	string	optional
<SerialNumber>	string	optional
<InstallationDate>	dateTime	optional
<RemovalDate>	dateTime	optional
<CalibrationDate>	dateTime	optional, many

<Type>

Channel → PreAmplifier → Type

content type: string

Type of equipment

<Description>

Channel → PreAmplifier → Description

content type: string

Description of equipment

<Manufacturer>

Channel → PreAmplifier → Manufacturer

content type: string

Manufacturer of equipment

<Vendor>

Channel → PreAmplifier → Vendor

content type: string

Vendor of equipment

<Model>

Channel → PreAmplifier → Model

content type: string

Model of equipment

<SerialNumber>

Channel → PreAmplifier → SerialNumber

content type: string

Serial number of equipment

<InstallationDate>

Channel → PreAmplifier → InstallationDate

content type: dateTime

Date this equipment was installed

<RemovalDate>

Channel → PreAmplifier → RemovalDate

content type: dateTime

Date this equipment was removed

<CalibrationDate>

Channel → PreAmplifier → CalibrationDate

content type: dateTime

Date this equipment was calibrated

2.4.20. <DataLogger>

Channel → DataLogger

Datalogger that recorded this channel. If this was entered at the Station level, it is not necessary to do it for each Channel, unless you have differences in equipment.

A type for equipment related to data acquisition or processing.

Attributes of <DataLogger>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information or be derived from the same base instruments.

Sub Elements of <DataLogger>:

element	type	number
<Type>	string	optional
<Description>	string	optional
<Manufacturer>	string	optional
<Vendor>	string	optional
<Model>	string	optional
<SerialNumber>	string	optional
<InstallationDate>	dateTime	optional
<RemovalDate>	dateTime	optional
<CalibrationDate>	dateTime	optional, many

<Type>

Channel → DataLogger → Type

content type: string

Type of equipment

<Description>

Channel → DataLogger → Description

content type: string

Description of equipment

<Manufacturer>

Channel → DataLogger → Manufacturer

content type: string

Manufacturer of equipment

<Vendor>

Channel → DataLogger → Vendor

content type: string

Vendor of equipment

<Model>

Channel → DataLogger → Model

content type: string

Model of equipment

<SerialNumber>

Channel → DataLogger → SerialNumber

content type: string

Serial number of equipment

<InstallationDate>

Channel → DataLogger → InstallationDate

content type: dateTime

Date this equipment was installed

<RemovalDate>

Channel → DataLogger → RemovalDate

content type: dateTime

Date this equipment was removed

<CalibrationDate>

Channel → DataLogger → CalibrationDate

content type: dateTime

Date this equipment was calibrated

2.4.21. <Equipment>

Channel → Equipment

Any equipment that does not have type-specific fields. Equipment such as sensor, data logger and preamplifier that has type-specific fields should be documented in those structures. If the same Equipment is entered at the Station level, it is not necessary to include it for each Channel. If using a preamplifier, sensor, or datalogger, use their appropriate fields instead.

A type for equipment related to data acquisition or processing.

Attributes of <Equipment>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information or be derived from the same base instruments.

Sub Elements of <Equipment>:

element	type	number
<Type>	string	optional
<Description>	string	optional
<Manufacturer>	string	optional
<Vendor>	string	optional
<Model>	string	optional
<SerialNumber>	string	optional
<InstallationDate>	dateTime	optional
<RemovalDate>	dateTime	optional
<CalibrationDate>	dateTime	optional, many

<Type>

Channel → Equipment → Type

content type: string

Type of equipment

<Description>

Channel → Equipment → Description

content type: string

Description of equipment

<Manufacturer>

Channel → Equipment → Manufacturer

content type: string

Manufacturer of equipment

<Vendor>

Channel → Equipment → Vendor

content type: string

Vendor of equipment

<Model>

Channel → Equipment → Model

content type: string

Model of equipment

<SerialNumber>

Channel → Equipment → SerialNumber

content type: string

Serial number of equipment

<InstallationDate>

Channel → Equipment → InstallationDate

content type: dateTime

Date this equipment was installed

<RemovalDate>

Channel → Equipment → RemovalDate

content type: dateTime

Date this equipment was removed

<CalibrationDate>

Channel → Equipment → CalibrationDate

content type: dateTime

Date this equipment was calibrated

2.5. <Response>

The complete instrument response for this channel that expresses the effect of the geophysical instrumentation used to record the input ground motion. The information can be used to convert raw data to Earth unit measurement at a specified frequency or within a range of frequencies. It is strongly suggested that either InstrumentSensitivity or InstrumentPolynomial should be present.

In cases where the response is unknown, for example really old channels, or where a response is not applicable, like textual log channels, it is preferred that an empty response element be used, <response></response>, to positively indicate that no response exists.

Attributes of <Response>:

attribute	type	required	description	example
resourceId	string	no	An identifier that serves to uniquely identify this resource. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same ID should indicate the same information.

Sub Elements of <Response>:

element	type	number
<InstrumentSensitivity>		optional
<InstrumentPolynomial>		optional
<Stage>		optional, many

2.5.1. <InstrumentSensitivity>

Response → InstrumentSensitivity

The total sensitivity for a channel, representing the complete acquisition system expressed as a scalar. All instrument responses except polynomial response should have an InstrumentSensitivity.

Type for sensitivity, input/output units and relevant frequency range.

Sub Elements of <InstrumentSensitivity>:

element	type	number
<Value>	double	required
<Frequency>	double	required
<InputUnits>		required
<OutputUnits>		required
<FrequencyStart>	double	optional
<FrequencyEnd>	double	optional
<FrequencyDBVariation>	double	optional

<Value> required

Response → InstrumentSensitivity → Value

content type: double

A scalar value representing the amount of amplification or diminution, if any, the current stage applies to the input signal.

<Frequency> required

Response → InstrumentSensitivity → Frequency

content type: double

The frequency (in Hertz) at which the Value is valid.

While any frequency in the passband is acceptable, it is preferred that:

1. For low pass FIR filters, use gain at zero frequency (sum of coefficients)

2. If given, use manufacturer frequency/gain without recomputing

3. For anything else, frequency should be in the “good” part of the passband

4. All stage frequencies should be below the final Nyquist, as long as 2,3 are satisfied

5. All stages, except lowpass FIR filters, should use the same frequencies, as long as 2,3 are satisfied

6. Overall gain should also use the same frequency as 5, as long as it is below the final Nyquist and in the good part of the final passband

<InputUnits> required

Response → InstrumentSensitivity → InputUnits

The units of the data as input to the sensor. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → InstrumentSensitivity → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → InstrumentSensitivity → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → InstrumentSensitivity → OutputUnits

The units of the data as output from data acquisition system. For most channels recorded by systems that use an AtoD, the OutputUnits will be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → InstrumentSensitivity → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → InstrumentSensitivity → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<FrequencyStart>

Response → InstrumentSensitivity → FrequencyStart

content type: double

The lowest frequency for which the InstrumentSensitivity is valid. <FrequencyStart>, <FrequencyEnd> and <FrequencyDBVariation> are not required, however, if one of these is present, then all must be present.

<FrequencyEnd>

Response → InstrumentSensitivity → FrequencyEnd

content type: double

The highest frequency for which the InstrumentSensitivity is valid. <FrequencyStart>, <FrequencyEnd> and <FrequencyDBVariation> are not required, however, if one of these is present, then all must be present.

<FrequencyDBVariation>

Response → InstrumentSensitivity → FrequencyDBVariation

content type: double

Variation in decibels within the specified frequency range. <FrequencyStart>, <FrequencyEnd> and <FrequencyDBVariation> are not required, however, if one of these is present, then all must be present.

2.5.2. <InstrumentPolynomial>

Response → InstrumentPolynomial

For non-linear sensors (e.g., \(N\ge 2\)), such as some thermistors, pressure transducers, extensometers, etc.), it is required to express the sensor input (e.g., Temp) as a Maclaurin series expansion of powers of the output units (e.g., Volts):

\[Temp(V)=\sum_{k=0}^{N} a_k V^{k}\]

For such responses, two StationXML components are required to specify the response: 1. A Polynomial stage, which contains the values of the Maclaurin coefficients, \(a_k\), and 2. An InstrumentPolynomial element that contains the same coefficients, but scaled by powers of the overall gain representing the combined effect of all the stages in the complete acquisition system.

Response type for a response represented as a polynomial expansion, which allows non-linear sensors to be described. Used at either a stage of acquisition response or a complete system.

Attributes of <InstrumentPolynomial>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <InstrumentPolynomial>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<ApproximationType>	string	required
<FrequencyLowerBound>	double	required
<FrequencyUpperBound>	double	required
<ApproximationLowerBound>	double	required
<ApproximationUpperBound>	double	required
<MaximumError>	double	required
<Coefficient>	double	required, many

<Description>

Response → InstrumentPolynomial → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → InstrumentPolynomial → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → InstrumentPolynomial → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → InstrumentPolynomial → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → InstrumentPolynomial → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → InstrumentPolynomial → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → InstrumentPolynomial → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<ApproximationType> required

Response → InstrumentPolynomial → ApproximationType

content type: string

The series type for the polynomial approximation

<FrequencyLowerBound> required

Response → InstrumentPolynomial → FrequencyLowerBound

content type: double

The lower bound of the frequency range.

Attributes of <FrequencyLowerBound>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<FrequencyUpperBound> required

Response → InstrumentPolynomial → FrequencyUpperBound

content type: double

The upper bound of the frequency range.

Attributes of <FrequencyUpperBound>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<ApproximationLowerBound> required

Response → InstrumentPolynomial → ApproximationLowerBound

content type: double

The lower bound of the approximation range.

<ApproximationUpperBound> required

Response → InstrumentPolynomial → ApproximationUpperBound

content type: double

The upper bound of the approximation range.

<MaximumError> required

Response → InstrumentPolynomial → MaximumError

content type: double

The maximum error of the approximation.

<Coefficient> required

Response → InstrumentPolynomial → Coefficient

content type: double

Attributes of <Coefficient>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
number	CounterType	no

2.5.3. <Stage>

Response → Stage

Warning, Future Change

<Stage>: A filter, (PolesZeros, Coefficients, FIR, etc) may be required.

Type for channel response entry or stage. A full response is represented as an ordered sequence of these stages.

A filter, (PolesZeros, Coefficients, FIR, etc) is not required, but is recommended to provide a place to store the input and output units even in the case of “gain-only” stages.

For an analog gain-only stage, use a PolesZeros filter with no poles or zeros, PzTransferFunctionType=LAPLACE (RADIANS/SECOND)”, NormalizationFactor=1 and NormalizationFrequency=0.

For a digital gain-only stage, use a FIR filter with one numerator with value 1.0, and symmetry=NONE. While a digital Coefficients filter can serve the same purpose and is common, the FIR filter is more concise.

Attributes of <Stage>:

attribute	type	required	description	example
number	CounterType	yes	Stage sequence number. This is used in all the response blockettes. Start from name=’1’ and iterate sequentially.
resourceId	string	no	A resource identifier that serves to uniquely identify this response stage. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that equipment with the same ID should indicate the same information.

Sub Elements of <Stage>:

element	type	number
<PolesZeros>		optional
<Coefficients>		optional
<ResponseList>		optional
<FIR>		optional
<Decimation>		optional
<StageGain>		required
<Polynomial>		required

<PolesZeros>

Response → Stage → PolesZeros

Response stage described by the complex poles and zeros of the Laplace Transform (or z-transform) of the transfer function for this stage.

Attributes of <PolesZeros>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <PolesZeros>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<PzTransferFunctionType>	string	required
<NormalizationFactor>	double	required
<NormalizationFrequency>	double	required
<Zero>		optional, many
<Pole>		optional, many

<Description>

Response → Stage → PolesZeros → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → Stage → PolesZeros → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → PolesZeros → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → PolesZeros → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → Stage → PolesZeros → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → PolesZeros → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → PolesZeros → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<PzTransferFunctionType> required

Response → Stage → PolesZeros → PzTransferFunctionType

content type: string

Allowable values are:”LAPLACE (RADIANS/SECOND)”, “LAPLACE (HERTZ)”, “DIGITAL (Z-TRANSFORM)”. For an analog stage this should be the units of the poles and zeros of the Laplace Transform, either: “LAPLACE (RADIANS/SECOND)” or “LAPLACE (HERTZ)”. For a digital z-transform (e.g., for an IIR filter), this should be “DIGITAL (Z-TRANSFORM)”

Example: <PzTransferFunctionType>LAPLACE (RADIANS/SECOND)</PzTransferFunctionType>

<NormalizationFactor> required

Response → Stage → PolesZeros → NormalizationFactor

content type: double

Normalization scale factor

<NormalizationFrequency> required

Response → Stage → PolesZeros → NormalizationFrequency

content type: double

Frequency at which the NormalizationFactor is valid. This should be the same for all stages and within the passband, if any.

Attributes of <NormalizationFrequency>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Zero>

Response → Stage → PolesZeros → Zero

Complex zero of the polezero stage.

Attributes of <Zero>:

attribute	type	required	description	example
number	integer	no	The position index of the pole (or zero) in the array of poles[] (or zeros[])	number=”None”

Sub Elements of <Zero>:

element	type	number
<Real>	double	required
<Imaginary>	double	required

<Real> required

Response → Stage → PolesZeros → Zero → Real

content type: double

Real part of the complex number.

Representation of floating-point numbers without unit.

Attributes of <Real>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Imaginary> required

Response → Stage → PolesZeros → Zero → Imaginary

content type: double

Imaginary part of the complex number.

Representation of floating-point numbers without unit.

Attributes of <Imaginary>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Pole>

Response → Stage → PolesZeros → Pole

Complex pole of the polezero stage.

Attributes of <Pole>:

attribute	type	required	description	example
number	integer	no	The position index of the pole (or zero) in the array of poles[] (or zeros[])	number=”None”

Sub Elements of <Pole>:

element	type	number
<Real>	double	required
<Imaginary>	double	required

<Real> required

Response → Stage → PolesZeros → Pole → Real

content type: double

Real part of the complex number.

Representation of floating-point numbers without unit.

Attributes of <Real>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Imaginary> required

Response → Stage → PolesZeros → Pole → Imaginary

content type: double

Imaginary part of the complex number.

Representation of floating-point numbers without unit.

Attributes of <Imaginary>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Coefficients>

Response → Stage → Coefficients

Warning, Future Change

<Coefficients>: The Numerator element is likely to be changed to require at least one numerator.

Response type for filter giving coefficients. Laplace transforms or analog filters can both be expressed using this type as well but the PolesZeros should be used instead. Digital filters with no denominator should use FIR instead.

Attributes of <Coefficients>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <Coefficients>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<CfTransferFunctionType>	string	required
<Numerator>	double	optional, many
<Denominator>	double	optional, many

<Description>

Response → Stage → Coefficients → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → Stage → Coefficients → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → Coefficients → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → Coefficients → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → Stage → Coefficients → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → Coefficients → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → Coefficients → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<CfTransferFunctionType> required

Response → Stage → Coefficients → CfTransferFunctionType

content type: string

Almost always a digital response, but can be an analog response in rad/sec or Hertz.

<Numerator>

Response → Stage → Coefficients → Numerator

Warning, Future Change

<Numerator>: At least one Numerator may be required.

content type: double

Numerator for the coefficient. Should include at least one.

Attributes of <Numerator>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
number	CounterType	no

<Denominator>

Response → Stage → Coefficients → Denominator

content type: double

Denominator for the coefficient

Attributes of <Denominator>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
number	CounterType	no

<ResponseList>

Response → Stage → ResponseList

Response type for a list of frequency, amplitude, and phase values. Because it is less flexible, the other filter types, PolesZeros, Coefficients, FIR, etc, are preferred.

Attributes of <ResponseList>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <ResponseList>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<ResponseListElement>		optional, many

<Description>

Response → Stage → ResponseList → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → Stage → ResponseList → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → ResponseList → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → ResponseList → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → Stage → ResponseList → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → ResponseList → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → ResponseList → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<ResponseListElement>

Response → Stage → ResponseList → ResponseListElement

Sub Elements of <ResponseListElement>:

element	type	number
<Frequency>	double	required
<Amplitude>	double	required
<Phase>	double	required

<Frequency> required

Response → Stage → ResponseList → ResponseListElement → Frequency

content type: double

Attributes of <Frequency>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Amplitude> required

Response → Stage → ResponseList → ResponseListElement → Amplitude

content type: double

Attributes of <Amplitude>:

attribute	type	required	description	example
unit	string	no	The unit of measurement. Use SI unit names and symbols whenever possible (e.g., ‘m’ instead of ‘METERS’).	unit=”m”
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Phase> required

Response → Stage → ResponseList → ResponseListElement → Phase

content type: double

range: -360.0 \(\le\) Phase \(\le\) 360.0

Attributes of <Phase>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be DEGREES, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<FIR>

Response → Stage → FIR

Warning, Future Change

<FIR>: The NumeratorCoefficient field is likely to be changed to require at least one numerator in future versions of StationXML.

Warning, Future Change

<FIR>: The NumeratorCoefficient field is likely to be renamed to Numerator in future versions of StationXML.

Response type for FIR filter. FIR filters are also commonly documented using a digital Coefficients element with no denominators, but it is preferred to use this type allowing representation of symmetric FIR coefficients without repeating them.

Attributes of <FIR>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <FIR>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<Symmetry>	string	required
<NumeratorCoefficient>	double	optional, many

<Description>

Response → Stage → FIR → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → Stage → FIR → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → FIR → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → FIR → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → Stage → FIR → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → FIR → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → FIR → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<Symmetry> required

Response → Stage → FIR → Symmetry

content type: string

The symmetry code. Designates how the factors will be specified.

• NONE: No Symmetry - all Coefficients are specified, corresponds to A in SEED.

• ODD: Odd number Coefficients with symmetry, B in SEED.

• EVEN: Even number Coefficients with symmetry, C in SEED.

<NumeratorCoefficient>

Response → Stage → FIR → NumeratorCoefficient

Warning, Future Change

<NumeratorCoefficient>: At least one Numerator may be required.

Warning, Future Change

<NumeratorCoefficient>: May be renamed to Numerator.

content type: double

The coefficients of the FIR filter. Should include at least one.

Attributes of <NumeratorCoefficient>:

attribute	type	required	description	example
i	integer	no

<Decimation>

Response → Stage → Decimation

Representation of decimation stage

Sub Elements of <Decimation>:

element	type	number
<InputSampleRate>	double	required
<Factor>	integer	required
<Offset>	integer	required
<Delay>	double	required
<Correction>	double	required

<InputSampleRate> required

Response → Stage → Decimation → InputSampleRate

content type: double

Attributes of <InputSampleRate>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Factor> required

Response → Stage → Decimation → Factor

content type: integer

The factor of the input sample rate by which the rate is reduced.

<Offset> required

Response → Stage → Decimation → Offset

content type: integer

Sample offset chosen for use. The value should be greater than or equal to zero, but less than the decimation factor. If the first sample is used, set this field to zero. If the second sample, set it to 1, and so forth.

<Delay> required

Response → Stage → Decimation → Delay

content type: double

The estimated pure delay for the stage. This value will almost always be positive to indicate a delayed signal. Due to the difficulty in estimating the pure delay of a stage and because dispersion is neglected, this value should be considered nominal. Normally the delay would be corrected by the recording system and the correction applied would be specified in <Correction> below. See the Decimation Section in the StationXML documentation for a schematic description of delay sign convention.

Attributes of <Delay>:

attribute	type	required	description	example
unit	string	no	The unit of measurement. Use SI unit names and symbols whenever possible (e.g., ‘m’ instead of ‘METERS’).	unit=”s”
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<Correction> required

Response → Stage → Decimation → Correction

content type: double

The time shift, if any, applied to correct for the delay at this stage. The sign convention used is opposite the <Delay> value; a positive sign here indicates that the trace was corrected to an earlier time to cancel the delay caused by the stage and indicated in the <Delay> element. Commonly, the estimated delay and the applied correction are both positive to cancel each other. A value of zero indicates no correction was applied. See the Decimation Section in the StationXML documentation for a schematic description of delay sign convention.

Attributes of <Correction>:

attribute	type	required	description	example
unit	string	no	The unit of measurement. Use SI unit names and symbols whenever possible (e.g., ‘m’ instead of ‘METERS’).	unit=”s”
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<StageGain> required

Response → Stage → StageGain

The gain at the stage of the encapsulating response element at a specific frequency. Total channel sensitivity should be specified in the InstrumentSensitivity element.

Type used for representing sensitivity at a given frequency. This complex type can be used to represent both total sensitivities and individual stage gains.

Sub Elements of <StageGain>:

element	type	number
<Value>	double	required
<Frequency>	double	required

<Value> required

Response → Stage → StageGain → Value

content type: double

A scalar value representing the amount of amplification or diminution, if any, the current stage applies to the input signal.

<Frequency> required

Response → Stage → StageGain → Frequency

content type: double

The frequency (in Hertz) at which the Value is valid.

While any frequency in the passband is acceptable, it is preferred that:

1. For low pass FIR filters, use gain at zero frequency (sum of coefficients)

2. If given, use manufacturer frequency/gain without recomputing

3. For anything else, frequency should be in the “good” part of the passband

4. All stage frequencies should be below the final Nyquist, as long as 2,3 are satisfied

5. All stages, except lowpass FIR filters, should use the same frequencies, as long as 2,3 are satisfied

6. Overall gain should also use the same frequency as 5, as long as it is below the final Nyquist and in the good part of the final passband

<Polynomial>

Response → Stage → Polynomial

When a response is given in terms of a polynomial expansion of powers of the sensor output signal (e.g., Volts), a Polynomial stage is required to specify the Maclaurin coefficients of the expansion.

In addition, an InstrumentPolynomial element must be present at Response level to represent the whole acquisition process, which contains the same Maclaurin coefficients, but scaled by powers of the overall gain for all stages.

Response type for a response represented as a polynomial expansion, which allows non-linear sensors to be described. Used at either a stage of acquisition response or a complete system.

Attributes of <Polynomial>:

attribute	type	required	description	example
name	string	no	A name given to this filter.
resourceId	string	no	A resource identifier that serves to unique identify this filter or response. This identifier can be interpreted differently depending on the datacenter/software that generated the document. Also, we recommend using a prefix, e.g., GENERATOR:Meaningful ID. It should be expected that elements with the same resourceId should indicate the same information.

Sub Elements of <Polynomial>:

element	type	number
<Description>	string	optional
<InputUnits>		required
<OutputUnits>		required
<ApproximationType>	string	required
<FrequencyLowerBound>	double	required
<FrequencyUpperBound>	double	required
<ApproximationLowerBound>	double	required
<ApproximationUpperBound>	double	required
<MaximumError>	double	required
<Coefficient>	double	required, many

<Description>

Response → Stage → Polynomial → Description

content type: string

The description of the filter/stage/response

<InputUnits> required

Response → Stage → Polynomial → InputUnits

The units of the data as input from the previous stage. For example if stage 1 represented a seismometer, InputUnits would be ‘m/s’ and OutputUnits would be ‘V’.

A type to document units; use SI whenever possible.

Sub Elements of <InputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → Polynomial → InputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → Polynomial → InputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<OutputUnits> required

Response → Stage → Polynomial → OutputUnits

The units of the data as output to the following stage. For example if stage 2 represented the AtoD stage of a data logger, InputUnits would be ‘V’ and OutputUnits would be ‘count’.

A type to document units; use SI whenever possible.

Sub Elements of <OutputUnits>:

element	type	number
<Name>	string	required
<Description>	string	optional

<Name> required

Response → Stage → Polynomial → OutputUnits → Name

content type: string

Symbol or name of units, e.g. “m/s”, “V”, “Pa”, “C”. Use SI whenever possible, along with singular lowercase “count” for digital counts.

<Description>

Response → Stage → Polynomial → OutputUnits → Description

content type: string

Description of units, e.g. “Velocity in meters per second”, “Volts”, “Pascals”, “Degrees Celsius”. Description is only needed when the unit name is not a well know SI unit or there is need for clarification. Prefer not to use a Description for common units like m/s, m/s**2, count, etc.

<ApproximationType> required

Response → Stage → Polynomial → ApproximationType

content type: string

The series type for the polynomial approximation

<FrequencyLowerBound> required

Response → Stage → Polynomial → FrequencyLowerBound

content type: double

The lower bound of the frequency range.

Attributes of <FrequencyLowerBound>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<FrequencyUpperBound> required

Response → Stage → Polynomial → FrequencyUpperBound

content type: double

The upper bound of the frequency range.

Attributes of <FrequencyUpperBound>:

attribute	type	required	description	example
unit	string	no	The type of unit being used. This value is fixed to be HERTZ, setting it is redundant.
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no

<ApproximationLowerBound> required

Response → Stage → Polynomial → ApproximationLowerBound

content type: double

The lower bound of the approximation range.

<ApproximationUpperBound> required

Response → Stage → Polynomial → ApproximationUpperBound

content type: double

The upper bound of the approximation range.

<MaximumError> required

Response → Stage → Polynomial → MaximumError

content type: double

The maximum error of the approximation.

<Coefficient> required

Response → Stage → Polynomial → Coefficient

content type: double

Attributes of <Coefficient>:

attribute	type	required	description	example
plusError	double	no	plus uncertainty or error in measured value.	plusError=”0.1”
minusError	double	no	minus uncertainty or error in measured value.	minusError=”0.1”
measurementMethod	string	no
number	CounterType	no