<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns="http://water.usgs.gov/XML/AQ" xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://water.usgs.gov/XML/AQ" elementFormDefault="qualified" version="1.0">
  <xsd:include schemaLocation="Sensor.xsd"/>
  <xsd:include schemaLocation="GeneralVelocitySensor.xsd"/>
  <xsd:include schemaLocation="MechanicalVelocitySensor.xsd"/>
  <xsd:include schemaLocation="AcousticDopplerCurrentProfiler.xsd"/>
  <xsd:include schemaLocation="AcousticDopplerVelocitySensor.xsd"/>
  <xsd:include schemaLocation="Equipment.xsd"/>

  <xsd:element name="FieldEquipment">
    <xsd:annotation>
      <xsd:documentation>
        <Definition>Equipment (sensors, current meters, and monitors) used in the field and/or not currently installed at a site.</Definition>
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="Sensor" type="Sensor" minOccurs="0" maxOccurs="unbounded"/>
        <xsd:choice minOccurs="0" maxOccurs="unbounded">
          <xsd:element ref="GeneralVelocitySensor"/>
          <xsd:element ref="MechanicalVelocitySensor"/>
          <xsd:element ref="AcousticDopplerCurrentProfiler"/>
          <xsd:element ref="AcousticDopplerVelocitySensor"/>
        </xsd:choice>
        <xsd:element name="Equipment" type="EquipmentType" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>
