<?xml version="1.0" encoding="UTF-8"?>
<!-- 	
	FDSN StationXML (www.fdsn.org/xml/station)

	The purpose of this schema is to define an XML representation of the most important
	and commonly used structures of SEED 2.4 metadata.

	The goal is to allow mapping between SEED 2.4 dataless SEED volumes and this schema with as
	little transformation or loss of information as possible while at the same time simplifying
	station metadata representation when possible.  Also, content and clarification has been added
	where lacking in the SEED standard.
	
	When definitions and usage are underdefined the SEED manual should be referred to for
	clarification.  SEED specifiation: http://www.fdsn.org/publications.htm
	
	Another goal is to create a base schema that can be extended to represent similar data types.


	Versioning for FDSN StationXML:

	The 'version' attribute of the schema definition identifies the version of the schema.  This
	version is not enforced when validating documents.
	
	The required 'schemaVersion' attribute of the root element identifies the version of the schema
	that the document is compatible with.  Validation only requires that a value is present but
	not that it matches the schema used for validation.

	The targetNamespace of the document identifies the major version of the schema and document,
	version 1.x of the schema uses a target namespace of "http://www.fdsn.org/xml/station/1".
	All minor versions of a will be backwards compatible with previous minor releases.  For
	example, all 1.x schemas are backwards compatible with and will validate documents for 1.0.
	Major changes to the schema that would break backwards compabibility will increment the major
	version number, e.g. 2.0, and the namespace, e.g. "http://www.fdsn.org/xml/station/2".

	This combination of attributes and targetNamespaces allows the schema and documents to be
	versioned and allows the schema to be updated with backward compatible changes (e.g. 1.2)
	and still validate documents created for previous major versions of the schema (e.g. 1.0).

-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:fsx="http://www.fdsn.org/xml/station/1" targetNamespace="http://www.fdsn.org/xml/station/1" elementFormDefault="qualified" attributeFormDefault="unqualified" version="1.0">
	<xs:annotation>
		<xs:documentation> FDSN StationXML schema. Designed as an XML representation of SEED
			metadata, the schema maps to the most important and commonly used structures of SEED
			2.4. When definitions and usage are underdefined the SEED manual should be referred to
			for clarification.</xs:documentation>
	</xs:annotation>
	<!-- Root element -->
	<xs:element name="FDSNStationXML" type="fsx:RootType"/>
	<!-- Type definitions -->
	<xs:complexType name="RootType">
		<xs:annotation>
			<xs:documentation>Top-level type for Station XML. Required field are Source (network ID
				of the institution sending the message) and one or more Network containers or one or
				more Station containers. </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Source" type="xs:string">
				<xs:annotation>
					<xs:documentation>Network ID of the institution sending the
						message.</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Sender" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation>Name of the institution sending this
						message.</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Module" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation>Name of the software module that generated this document.
					</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="ModuleURI" type="xs:anyURI" minOccurs="0">
				<xs:annotation>
					<xs:documentation> This is the address of the query that generated the document,
						or, if applicable, the address of the software that generated this document.
					</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Created" type="xs:dateTime"/>
			<xs:element name="Network" type="fsx:NetworkType" maxOccurs="unbounded"/>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="schemaVersion" type="xs:decimal" use="required">
			<xs:annotation>
				<xs:documentation>The schema version compatible with the document.
				</xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="NetworkType">
		<xs:annotation>
			<xs:documentation>This type represents the Network layer, all station metadata is
				contained within this element. The official name of the network or other descriptive
				information can be included in the Description element. The Network can contain 0 or
				more Stations. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseNodeType">
				<xs:sequence>
					<xs:element name="TotalNumberStations" type="fsx:CounterType" minOccurs="0">
						<xs:annotation>
							<xs:documentation> The total number of stations contained in this
								network, including inactive or terminated stations.
							</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="SelectedNumberStations" type="fsx:CounterType" minOccurs="0">
						<xs:annotation>
							<xs:documentation> The total number of stations in this network that
								were selected by the query that produced this document, even if the
								stations do not appear in the document. (This might happen if the
								user only wants a document that goes contains only information at
								the Network level.) </xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Station" type="fsx:StationType" minOccurs="0" maxOccurs="unbounded"/>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="StationType">
		<xs:annotation>
			<xs:documentation>This type represents a Station epoch. It is common to only have a
				single station epoch with the station's creation and termination dates as the epoch
				start and end dates. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseNodeType">
				<xs:sequence>
					<xs:element name="Latitude" type="fsx:LatitudeType"/>
					<xs:element name="Longitude" type="fsx:LongitudeType"/>
					<xs:element name="Elevation" type="fsx:DistanceType"/>
					<xs:element name="Site" type="fsx:SiteType">
						<xs:annotation>
							<xs:documentation>These fields describe the location of the station
								using geopolitical entities (country, city,
								etc.).</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Vault" type="xs:string" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Type of vault, e.g. WWSSN, tunnel, transportable
								array, etc.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Geology" type="xs:string" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Type of rock and/or geologic
								formation.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Equipment" type="fsx:EquipmentType" minOccurs="0" maxOccurs="unbounded">
						<xs:annotation>
							<xs:documentation>Equipment used by all channels at a
								station.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Operator" minOccurs="0" maxOccurs="unbounded">
						<xs:annotation>
							<xs:documentation>An operating agency and associated contact persons. If
								there multiple operators, each one should be encapsulated within an
								Operator tag. Since the Contact element is a generic type that
								represents any contact person, it also has its own optional Agency
								element.</xs:documentation>
						</xs:annotation>
						<xs:complexType>
							<xs:sequence>
								<xs:element name="Agency" type="xs:string" maxOccurs="unbounded"/>
								<xs:element name="Contact" type="fsx:PersonType" minOccurs="0" maxOccurs="unbounded"/>
								<xs:element name="WebSite" type="xs:anyURI" minOccurs="0"/>
							</xs:sequence>
						</xs:complexType>
					</xs:element>
					<xs:element name="CreationDate" type="xs:dateTime">
						<xs:annotation>
							<xs:documentation>Date and time (UTC) when the station was first
								installed.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="TerminationDate" type="xs:dateTime" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Date and time (UTC) when the station was terminated or
								will be terminated. A blank value should be assumed to mean that the
								station is still active.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="TotalNumberChannels" type="fsx:CounterType" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Total number of channels recorded at this
								station.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="SelectedNumberChannels" type="fsx:CounterType" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Number of channels recorded at this station and
								selected by the query that produced this
								document.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="ExternalReference" type="fsx:ExternalReferenceType" minOccurs="0" maxOccurs="unbounded">
						<xs:annotation>
							<xs:documentation>URI of any type of external report, such as IRIS data
								reports or dataless SEED volumes.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Channel" type="fsx:ChannelType" minOccurs="0" maxOccurs="unbounded"/>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<!-- End StationType-->
	<xs:complexType name="ChannelType">
		<xs:annotation>
			<xs:documentation>Equivalent to SEED blockette 52 and parent element for the related the
				response blockettes.</xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseNodeType">
				<xs:sequence>
					<xs:element name="ExternalReference" type="fsx:ExternalReferenceType" minOccurs="0" maxOccurs="unbounded">
						<xs:annotation>
							<xs:documentation>URI of any type of external report, such as data
								quality reports.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Latitude" type="fsx:LatitudeType">
						<xs:annotation>
							<xs:documentation>Latitude coordinate of this channel's
								sensor.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Longitude" type="fsx:LongitudeType">
						<xs:annotation>
							<xs:documentation>Longitude coordinate of this channel's
								sensor.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Elevation" type="fsx:DistanceType">
						<xs:annotation>
							<xs:documentation>Elevation of the sensor.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Depth" type="fsx:DistanceType">
						<xs:annotation>
							<xs:documentation>The local depth or overburden of the instrument's
								location. For downhole instruments, the depth of the instrument
								under the surface ground level. For underground vaults, the distance
								from the instrument to the local ground level
								above.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Azimuth" type="fsx:AzimuthType" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Azimuth of the sensor in degrees from north,
								clockwise.</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Dip" type="fsx:DipType" minOccurs="0">
						<xs:annotation>
							<xs:documentation>Dip of the instrument in degrees, down from
								horizontal</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="Type" minOccurs="0" maxOccurs="unbounded">
						<xs:annotation>
							<xs:documentation>The type of data this channel collects. Corresponds to
								channel flags in SEED blockette 52. The SEED volume producer could
								use the first letter of an Output value as the SEED channel
								flag.</xs:documentation>
						</xs:annotation>
						<xs:simpleType>
							<xs:restriction base="xs:NMTOKEN">
								<xs:enumeration value="TRIGGERED"/>
								<xs:enumeration value="CONTINUOUS"/>
								<xs:enumeration value="HEALTH"/>
								<xs:enumeration value="GEOPHYSICAL"/>
								<xs:enumeration value="WEATHER"/>
								<xs:enumeration value="FLAG"/>
								<xs:enumeration value="SYNTHESIZED"/>
								<xs:enumeration value="INPUT"/>
								<xs:enumeration value="EXPERIMENTAL"/>
								<xs:enumeration value="MAINTENANCE"/>
								<xs:enumeration value="BEAM"/>
							</xs:restriction>
						</xs:simpleType>
					</xs:element>
					<xs:group ref="fsx:SampleRateGroup" minOccurs="0"/>
					<xs:element name="StorageFormat" type="xs:string" minOccurs="0">
						<xs:annotation>
							<xs:documentation>The storage format of the recorded data (e.g.
								SEED).</xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="ClockDrift" minOccurs="0">
						<xs:annotation>
							<xs:documentation>A tolerance value, measured in seconds per sample,
								used as a threshold for time error detection in data from the
								channel.</xs:documentation>
						</xs:annotation>
						<xs:complexType>
							<xs:simpleContent>
								<xs:restriction base="fsx:FloatType">
									<xs:minInclusive value="0"/>
									<xs:attribute name="unit" type="xs:string" use="optional" fixed="SECONDS/SAMPLE"/>
								</xs:restriction>
							</xs:simpleContent>
						</xs:complexType>
					</xs:element>
					<xs:element name="CalibrationUnits" type="fsx:UnitsType" minOccurs="0"/>
					<xs:element name="Sensor" type="fsx:EquipmentType" minOccurs="0"/>
					<xs:element name="PreAmplifier" type="fsx:EquipmentType" minOccurs="0"/>
					<xs:element name="DataLogger" type="fsx:EquipmentType" minOccurs="0"/>
					<xs:element name="Equipment" type="fsx:EquipmentType" minOccurs="0"/>
					<xs:element name="Response" type="fsx:ResponseType" minOccurs="0"/>
				</xs:sequence>
				<xs:attribute name="locationCode" type="xs:string" use="required"/>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<!-- End ChannelType -->
	<xs:complexType name="GainType">
		<xs:annotation>
			<xs:documentation>Complex type for sensitivity and frequency ranges. This complex type
				can be used to represent both overall sensitivities and individual stage gains. The
				FrequencyRangeGroup is an optional construct that defines a pass band in Hertz (
				FrequencyStart and FrequencyEnd) in which the SensitivityValue is valid within the
				number of decibels specified in FrequencyDBVariation. </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Value" type="xs:double">
				<xs:annotation>
					<xs:documentation>A scalar that, when applied to the data values, converts the
						data to different units (e.g. Earth units)</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Frequency" type="xs:double">
				<xs:annotation>
					<xs:documentation>The frequency (in Hertz) at which the Value is
						valid.</xs:documentation>
				</xs:annotation>
			</xs:element>
		</xs:sequence>
	</xs:complexType>
	<xs:group name="FrequencyRangeGroup">
		<xs:sequence>
			<xs:element name="FrequencyStart" type="xs:double"/>
			<xs:element name="FrequencyEnd" type="xs:double"/>
			<xs:element name="FrequencyDBVariation" type="xs:double">
				<xs:annotation>
					<xs:documentation>Variation in decibels within the specified
						range.</xs:documentation>
				</xs:annotation>
			</xs:element>
		</xs:sequence>
	</xs:group>
	<xs:complexType name="SensitivityType">
		<xs:annotation>
			<xs:documentation>Sensitivity and frequency ranges. The FrequencyRangeGroup is an
				optional construct that defines a pass band in Hertz (FrequencyStart and
				FrequencyEnd) in which the SensitivityValue is valid within the number of decibels
				specified in FrequencyDBVariation. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:GainType">
				<xs:sequence>
					<xs:element name="InputUnits" type="fsx:UnitsType">
						<xs:annotation>
							<xs:documentation> The units of the data as input from the perspective
								of data acquisition. After correcting data for this response, these
								would be the resulting units. </xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:element name="OutputUnits" type="fsx:UnitsType">
						<xs:annotation>
							<xs:documentation> The units of the data as output from the perspective
								of data acquisition. These would be the units of the data prior to
								correcting for this response. </xs:documentation>
						</xs:annotation>
					</xs:element>
					<xs:group ref="fsx:FrequencyRangeGroup" minOccurs="0">
						<xs:annotation>
							<xs:documentation>The frequency range for which the SensitivityValue is
								valid within the dB variation specified.</xs:documentation>
						</xs:annotation>
					</xs:group>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="EquipmentType">
		<xs:sequence>
			<xs:element name="Type" type="xs:string" minOccurs="0"/>
			<xs:element name="Description" type="xs:string" minOccurs="0"/>
			<xs:element name="Manufacturer" type="xs:string" minOccurs="0"/>
			<xs:element name="Vendor" type="xs:string" minOccurs="0"/>
			<xs:element name="Model" type="xs:string" minOccurs="0"/>
			<xs:element name="SerialNumber" type="xs:string" minOccurs="0"/>
			<xs:element name="InstallationDate" type="xs:dateTime" minOccurs="0"/>
			<xs:element name="RemovalDate" type="xs:dateTime" minOccurs="0"/>
			<xs:element name="CalibrationDate" type="xs:dateTime" minOccurs="0" maxOccurs="unbounded"/>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="resourceId" type="xs:string" use="optional">
			<xs:annotation>
				<xs:documentation>This field contains a string that should serve as a unique
					resource identifier. This identifier can be interpreted differently depending on
					the datacenter/software that generated the document. Also, we recommend to use
					something like GENERATOR:Meaningful ID. As a common behaviour equipment with the
					same ID should contains the same information/be derived from the same base
					instruments. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="ResponseStageType">
		<xs:annotation>
			<xs:documentation> This complex type represents channel response and covers SEED
				blockettes 53 to 56. </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:choice>
				<xs:annotation>
					<xs:documentation>A choice of response types. There should be one response per
						stage.</xs:documentation>
				</xs:annotation>
				<xs:element name="PolesZeros" type="fsx:PolesZerosType" minOccurs="0"/>
				<xs:element name="Coefficients" type="fsx:CoefficientsType" minOccurs="0"/>
				<xs:element name="ResponseList" type="fsx:ResponseListType" minOccurs="0"/>
				<xs:element name="FIR" type="fsx:FIRType" minOccurs="0"/>
				<xs:element name="Polynomial" type="fsx:PolynomialType" minOccurs="0"/>
			</xs:choice>
			<xs:element name="Decimation" type="fsx:DecimationType" minOccurs="0"/>
			<xs:element name="StageGain" type="fsx:GainType">
				<xs:annotation>
					<xs:documentation>StageSensitivity is the gain at the stage of the encapsulating
						response element and corresponds to SEED blockette 58. In the SEED
						convention, stage 0 gain represents the overall sensitivity of the channel.
						In this schema, stage 0 gains are allowed but are considered deprecated.
						Overall sensitivity should be specified in the InstrumentSensitivity
						element.</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="number" type="fsx:CounterType" use="required">
			<xs:annotation>
				<xs:documentation>Stage sequence number. This is used in all the response SEED
					blockettes.</xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:attribute name="resourceId" type="xs:string">
			<xs:annotation>
				<xs:documentation> Same meaning as Equipment:resourceId. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="LogType">
		<xs:annotation>
			<xs:documentation>Container for log entries.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Entry" type="fsx:CommentType" maxOccurs="unbounded"/>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="CommentType">
		<xs:annotation>
			<xs:documentation>Container for a comment or log entry. Corresponds to SEED blockettes
				31, 51 and 59.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Value" type="xs:string"/>
			<xs:element name="BeginEffectiveTime" type="xs:dateTime" minOccurs="0"/>
			<xs:element name="EndEffectiveTime" type="xs:dateTime" minOccurs="0"/>
			<xs:element name="Author" type="fsx:PersonType" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="id" type="fsx:CounterType"/>
	</xs:complexType>
	<xs:complexType name="PolesZerosType">
		<xs:annotation>
			<xs:documentation>Response: complex poles and zeros. Corresponds to SEED blockette
				53.</xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseFilterType">
				<xs:sequence>
					<xs:element name="PzTransferFunctionType">
						<xs:simpleType>
							<xs:restriction base="xs:string">
								<xs:enumeration value="LAPLACE (RADIANS/SECOND)"/>
								<xs:enumeration value="LAPLACE (HERTZ)"/>
								<xs:enumeration value="DIGITAL (Z-TRANSFORM)"/>
							</xs:restriction>
						</xs:simpleType>
					</xs:element>
					<xs:element name="NormalizationFactor" type="xs:double" default="1.0"/>
					<xs:element name="NormalizationFrequency" type="fsx:FrequencyType"/>
					<xs:element name="Zero" type="fsx:PoleZeroType" minOccurs="0" maxOccurs="unbounded"/>
					<xs:element name="Pole" type="fsx:PoleZeroType" minOccurs="0" maxOccurs="unbounded"/>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="FIRType">
		<xs:annotation>
			<xs:documentation>Response: FIR filter. Corresponds to SEED blockette 61. FIR filters
				are also commonly documented using the CoefficientsType element. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseFilterType">
				<xs:sequence>
					<xs:element name="Symmetry">
						<xs:simpleType>
							<xs:restriction base="xs:NMTOKEN">
								<xs:enumeration value="NONE"/>
								<xs:enumeration value="EVEN"/>
								<xs:enumeration value="ODD"/>
							</xs:restriction>
						</xs:simpleType>
					</xs:element>
					<xs:element name="NumeratorCoefficient" minOccurs="0" maxOccurs="unbounded">
						<xs:complexType>
							<xs:simpleContent>
								<xs:extension base="xs:double">
									<xs:attribute name="i" type="xs:integer"/>
								</xs:extension>
							</xs:simpleContent>
						</xs:complexType>
					</xs:element>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="CoefficientsType">
		<xs:annotation>
			<xs:documentation>Response: coefficients for FIR filter. Laplace transforms or IIR
				filters can be expressed using type as well but the PolesAndZerosType should be used
				instead. Corresponds to SEED blockette 54.</xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseFilterType">
				<xs:sequence>
					<xs:element name="CfTransferFunctionType">
						<xs:simpleType>
							<xs:restriction base="xs:string">
								<xs:enumeration value="ANALOG (RADIANS/SECOND)"/>
								<xs:enumeration value="ANALOG (HERTZ)"/>
								<xs:enumeration value="DIGITAL"/>
							</xs:restriction>
						</xs:simpleType>
					</xs:element>
					<xs:element name="Numerator" type="fsx:FloatType" minOccurs="0" maxOccurs="unbounded"/>
					<xs:element name="Denominator" type="fsx:FloatType" minOccurs="0" maxOccurs="unbounded"/>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="ResponseListElementType">
		<xs:sequence>
			<xs:element name="Frequency" type="fsx:FrequencyType"/>
			<xs:element name="Amplitude" type="fsx:FloatType"/>
			<xs:element name="Phase" type="fsx:AngleType"/>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="ResponseListType">
		<xs:annotation>
			<xs:documentation>Response: list of frequency, amplitude and phase values. Corresponds
				to SEED blockette 55. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseFilterType">
				<xs:sequence>
					<xs:element name="ResponseListElement" type="fsx:ResponseListElementType" minOccurs="0" maxOccurs="unbounded"/>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="PolynomialType">
		<xs:annotation>
			<xs:documentation>Response: expressed as a polynomial (allows non-linear sensors to be
				described). Corresponds to SEED blockette 62. Can be used to describe a stage of
				acquisition or a complete system. </xs:documentation>
		</xs:annotation>
		<xs:complexContent>
			<xs:extension base="fsx:BaseFilterType">
				<xs:sequence>
					<xs:element name="ApproximationType" default="MACLAURIN">
						<xs:simpleType>
							<xs:restriction base="xs:string">
								<xs:enumeration value="MACLAURIN"/>
							</xs:restriction>
						</xs:simpleType>
					</xs:element>
					<xs:element name="FrequencyLowerBound" type="fsx:FrequencyType"/>
					<xs:element name="FrequencyUpperBound" type="fsx:FrequencyType"/>
					<xs:element name="ApproximationLowerBound" type="xs:decimal"/>
					<xs:element name="ApproximationUpperBound" type="xs:decimal"/>
					<xs:element name="MaximumError" type="xs:decimal"/>
					<xs:element name="Coefficient" maxOccurs="unbounded">
						<xs:complexType>
							<xs:simpleContent>
								<xs:extension base="fsx:FloatNoUnitType">
									<xs:attribute name="number" type="fsx:CounterType"/>
								</xs:extension>
							</xs:simpleContent>
						</xs:complexType>
					</xs:element>
				</xs:sequence>
			</xs:extension>
		</xs:complexContent>
	</xs:complexType>
	<xs:complexType name="DecimationType">
		<xs:annotation>
			<xs:documentation>Corresponds to SEED blockette 57.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="InputSampleRate" type="fsx:FrequencyType"/>
			<xs:element name="Factor" type="xs:integer"/>
			<xs:element name="Offset" type="xs:integer"/>
			<xs:element name="Delay" type="fsx:FloatType"/>
			<xs:element name="Correction" type="fsx:FloatType"/>
		</xs:sequence>
	</xs:complexType>
	<!-- The following elements represent numbers. -->
	<xs:attributeGroup name="uncertaintyDouble">
		<xs:annotation>
			<xs:documentation>Expressing uncertainties or errors with a positive and a negative
				component. Both values should be given as positive integers, but minus_error is
				understood to actually be negative. </xs:documentation>
		</xs:annotation>
		<xs:attribute name="plusError" type="xs:double" use="optional"/>
		<xs:attribute name="minusError" type="xs:double" use="optional"/>
	</xs:attributeGroup>
	<xs:complexType name="FloatNoUnitType">
		<xs:simpleContent>
			<xs:extension base="xs:double">
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:extension>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="FloatType">
		<xs:annotation>
			<xs:documentation>Representation of floating-point numbers used as
				measurements.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:extension base="xs:double">
				<xs:attribute name="unit" type="xs:string" use="optional"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:extension>
		</xs:simpleContent>
	</xs:complexType>
	<!-- Derived from FloatType. -->
	<xs:complexType name="SecondType">
		<xs:annotation>
			<xs:documentation>A time value in seconds.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:attribute name="unit" type="xs:string" fixed="SECONDS"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="VoltageType">
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:attribute name="unit" type="xs:string" fixed="VOLTS"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="AngleType">
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:minInclusive value="-360"/>
				<xs:maxInclusive value="360"/>
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="DEGREES"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="LatitudeBaseType">
		<xs:annotation>
			<xs:documentation>Base latitude type. Because of the limitations of schema, defining
				this type and then extending it to create the real latitude type is the only way to
				restrict values while adding datum as an attribute.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:minInclusive value="-90"/>
				<xs:maxExclusive value="90"/>
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="DEGREES"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="LatitudeType">
		<xs:annotation>
			<xs:documentation>Type for latitude coordinate.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:extension base="fsx:LatitudeBaseType">
				<xs:attribute name="datum" type="xs:NMTOKEN" use="optional" default="WGS84"/>
			</xs:extension>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="LongitudeBaseType">
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:minInclusive value="-180"/>
				<xs:maxInclusive value="180"/>
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="DEGREES"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="LongitudeType">
		<xs:annotation>
			<xs:documentation>Type for longitude coordinate.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:extension base="fsx:LongitudeBaseType">
				<xs:attribute name="datum" type="xs:NMTOKEN" use="optional" default="WGS84"/>
			</xs:extension>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="AzimuthType">
		<xs:annotation>
			<xs:documentation>Instrument azimuth, degrees clockwise from North.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:minInclusive value="0"/>
				<xs:maxExclusive value="360"/>
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="DEGREES"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="DipType">
		<xs:annotation>
			<xs:documentation>Instrument dip in degrees down from horizontal. Together azimuth and
				dip describe the direction of the sensitive axis of the instrument.
			</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:minInclusive value="-90"/>
				<xs:maxInclusive value="90"/>
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="DEGREES"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="DistanceType">
		<xs:annotation>
			<xs:documentation>Extension of FloatType for distances, elevations, and
				depths.</xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:attribute name="unit" type="xs:string" use="optional" default="METERS"/>
				<xs:attributeGroup ref="fsx:uncertaintyDouble"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="FrequencyType">
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="HERTZ"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:group name="SampleRateGroup">
		<xs:annotation>
			<xs:documentation>This is a group of elements that represent sample rate. If this group
				is included, then SampleRate, which is the sample rate in samples per second, is
				required. SampleRateRatio, which is expressed as a ratio of number of samples in a
				number of seconds, is optional. If both are included, SampleRate should be
				considered more definitive. </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="SampleRate" type="fsx:SampleRateType"/>
			<xs:element name="SampleRateRatio" type="fsx:SampleRateRatioType" minOccurs="0"/>
		</xs:sequence>
	</xs:group>
	<xs:complexType name="SampleRateType">
		<xs:annotation>
			<xs:documentation> Sample rate in samples per second. </xs:documentation>
		</xs:annotation>
		<xs:simpleContent>
			<xs:restriction base="fsx:FloatType">
				<xs:attribute name="unit" type="xs:string" use="optional" fixed="SAMPLES/S"/>
			</xs:restriction>
		</xs:simpleContent>
	</xs:complexType>
	<xs:complexType name="SampleRateRatioType">
		<xs:annotation>
			<xs:documentation> Sample rate expressed as number of samples in a number of
				seconds.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="NumberSamples" type="xs:integer"/>
			<xs:element name="NumberSeconds" type="xs:integer"/>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="PoleZeroType">
		<xs:annotation>
			<xs:documentation> Complex numbers used as poles or zeros in channel
				response.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Real" type="fsx:FloatNoUnitType"/>
			<xs:element name="Imaginary" type="fsx:FloatNoUnitType"/>
		</xs:sequence>
		<xs:attribute name="number" type="xs:integer"/>
	</xs:complexType>
	<xs:simpleType name="CounterType">
		<xs:annotation>
			<xs:documentation>Integers greater than or equal to 0.</xs:documentation>
		</xs:annotation>
		<xs:restriction base="xs:integer">
			<xs:minInclusive value="0"/>
		</xs:restriction>
	</xs:simpleType>
	<xs:complexType name="PersonType">
		<xs:annotation>
			<xs:documentation>Representation of a person's contact information. A person can belong
				to multiple agencies and have multiple email addresses and phone
				numbers.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Name" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
			<xs:element name="Agency" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
			<xs:element name="Email" type="fsx:EmailType" minOccurs="0" maxOccurs="unbounded"/>
			<xs:element name="Phone" type="fsx:PhoneNumberType" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="SiteType">
		<xs:annotation>
			<xs:documentation> Description of a site location using name and optional geopolitical
				boundaries (country, city, etc.). </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Name" type="xs:string">
				<xs:annotation>
					<xs:documentation> The commonly used name of this station, equivalent to the
						SEED blockette 50, field 9. </xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Description" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation> A longer description of the location of this station, e.g.
						"NW corner of Yellowstone National Park" or "20 miles west of Highway 40."
					</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Town" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation> The town or city closest to the station.</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="County" type="xs:string" minOccurs="0"/>
			<xs:element name="Region" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation> The state, province, or region of this
						site.</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Country" type="xs:string" minOccurs="0"/>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="ExternalReferenceType">
		<xs:annotation>
			<xs:documentation>This type contains a URI and description for external data that users
				may want to reference in StationXML.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="URI" type="xs:anyURI"/>
			<xs:element name="Description" type="xs:string"/>
		</xs:sequence>
	</xs:complexType>
	<!-- Simple types -->
	<xs:simpleType name="NominalType">
		<xs:restriction base="xs:NMTOKEN">
			<xs:enumeration value="NOMINAL"/>
			<xs:enumeration value="CALCULATED"/>
		</xs:restriction>
	</xs:simpleType>
	<xs:simpleType name="EmailType">
		<xs:restriction base="xs:string">
			<xs:pattern value="[\w\.\-_]+@[\w\.\-_]+"/>
		</xs:restriction>
	</xs:simpleType>
	<xs:complexType name="PhoneNumberType">
		<xs:sequence>
			<xs:element name="CountryCode" type="xs:integer" minOccurs="0"/>
			<xs:element name="AreaCode" type="xs:integer"/>
			<xs:element name="PhoneNumber">
				<xs:simpleType>
					<xs:restriction base="xs:string">
						<xs:pattern value="[0-9]+-[0-9]+"/>
					</xs:restriction>
				</xs:simpleType>
			</xs:element>
		</xs:sequence>
		<xs:attribute name="description" type="xs:string" use="optional"/>
	</xs:complexType>
	<xs:simpleType name="RestrictedStatusType">
		<xs:restriction base="xs:NMTOKEN">
			<xs:enumeration value="open"/>
			<xs:enumeration value="closed"/>
			<xs:enumeration value="partial"/>
		</xs:restriction>
	</xs:simpleType>
	<xs:complexType name="UnitsType">
		<xs:annotation>
			<xs:documentation>A type to document units. Corresponds to SEED blockette
				34.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Name" type="xs:string">
				<xs:annotation>
					<xs:documentation>Name of units, e.g. "M/S", "V", "PA".</xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="Description" type="xs:string" minOccurs="0">
				<xs:annotation>
					<xs:documentation>Description of units, e.g. "Velocity in meters per second",
						"Volts", "Pascals".</xs:documentation>
				</xs:annotation>
			</xs:element>
		</xs:sequence>
	</xs:complexType>
	<xs:complexType name="BaseFilterType">
		<xs:annotation>
			<xs:documentation> The BaseFilterType is derived by all filters. </xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Description" type="xs:string" minOccurs="0"/>
			<xs:element name="InputUnits" type="fsx:UnitsType">
				<xs:annotation>
					<xs:documentation> The units of the data as input from the perspective of data
						acquisition. After correcting data for this response, these would be the
						resulting units. </xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:element name="OutputUnits" type="fsx:UnitsType">
				<xs:annotation>
					<xs:documentation> The units of the data as output from the perspective of data
						acquisition. These would be the units of the data prior to correcting for
						this response. </xs:documentation>
				</xs:annotation>
			</xs:element>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="resourceId" type="xs:string">
			<xs:annotation>
				<xs:documentation> Same meaning as Equipment:resourceId. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:attribute name="name" type="xs:string">
			<xs:annotation>
				<xs:documentation>A name given to this filter. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="ResponseType">
		<xs:sequence>
			<xs:choice minOccurs="0">
				<xs:annotation>
					<xs:documentation>Instrument sensitivities, or the complete system sensitivity,
						can be expressed using either a sensitivity value or a polynomial. The
						information can be used to convert raw data to Earth at a specified
						frequency or within a range of frequencies. </xs:documentation>
				</xs:annotation>
				<xs:element name="InstrumentSensitivity" type="fsx:SensitivityType" minOccurs="0">
					<xs:annotation>
						<xs:documentation> The total sensitivity for a channel, representing the
							complete acquisition system expressed as a scalar. Equivalent to SEED
							stage 0 gain with (blockette 58) with the ability to specify a frequency
							range. </xs:documentation>
					</xs:annotation>
				</xs:element>
				<xs:element name="InstrumentPolynomial" type="fsx:PolynomialType" minOccurs="0">
					<xs:annotation>
						<xs:documentation> The total sensitivity for a channel, representing the
							complete acquisition system expressed as a polynomial. Equivalent to
							SEED stage 0 polynomial (blockette 62). </xs:documentation>
					</xs:annotation>
				</xs:element>
			</xs:choice>
			<xs:element name="Stage" type="fsx:ResponseStageType" minOccurs="0" maxOccurs="unbounded"/>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="resourceId" type="xs:string">
			<xs:annotation>
				<xs:documentation> Same meaning as Equipment:resourceId. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
	<xs:complexType name="BaseNodeType">
		<xs:annotation>
			<xs:documentation>A base node type for derivation from: Network, Station and Channel
				types.</xs:documentation>
		</xs:annotation>
		<xs:sequence>
			<xs:element name="Description" type="xs:string" minOccurs="0"/>
			<xs:element name="Comment" type="fsx:CommentType" minOccurs="0" maxOccurs="unbounded"/>
			<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
		</xs:sequence>
		<xs:attribute name="code" type="xs:string" use="required"/>
		<xs:attribute name="startDate" type="xs:dateTime"/>
		<xs:attribute name="endDate" type="xs:dateTime"/>
		<xs:attribute name="restrictedStatus" type="fsx:RestrictedStatusType" use="optional"/>
		<xs:attribute name="alternateCode" type="xs:string" use="optional">
			<xs:annotation>
				<xs:documentation> A code used for display or association, alternate to the
					SEED-compliant code. </xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:attribute name="historicalCode" type="xs:string" use="optional">
			<xs:annotation>
				<xs:documentation> A previously used code if different from the current code.
				</xs:documentation>
			</xs:annotation>
		</xs:attribute>
		<xs:anyAttribute namespace="##other" processContents="lax"/>
	</xs:complexType>
</xs:schema>