<?xml version="1.0"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:mtk="http://www.rigacci.org/gpx/MtkExtensions/v1"
        targetNamespace="http://www.rigacci.org/gpx/MtkExtensions/v1"
        elementFormDefault="qualified"
        attributeFormDefault="unqualified">

  <annotation><documentation>
  This schema defines an extension to be used with the GPX 1.1 schema; it
  accomodates extra fields logged by GPS devices based un the MediaTek (MTK)
  chip. The root elements defined by this schema are intended to be used as
  child elements of the "extensions" elements in the GPX 1.1 schema. The GPX
  1.1 schema is available at http://www.topografix.com/GPX/1/1/gpx.xsd.
  </documentation></annotation>

  <element name="wptExtension" type="mtk:wptExtensionType" />

  <complexType name="wptExtensionType">
    <annotation><documentation>
    This type contains data fields available in MTK waypoints that cannot
    be represented in waypoints instances of GPX 1.1 schema.
    </documentation></annotation>
    <sequence>
      <element name="valid"      type="mtk:validFixType"   minOccurs="0" />
      <element name="speed"      type="float"              minOccurs="0" />
      <element name="heading"    type="float"              minOccurs="0" />
      <element name="satinview"  type="nonNegativeInteger" minOccurs="0" />
      <element name="satdata"    type="mtk:satdataType"    minOccurs="0" maxOccurs="unbounded"/>
      <element name="msec"       type="mtk:msecType"       minOccurs="0" />
      <element name="distance"   type="double"             minOccurs="0" />
      <element name="extensions" type="mtk:extensionsType" minOccurs="0" />
    </sequence>
  </complexType>

  <simpleType name="validFixType">
    <annotation><documentation>
    Type of GPS fix. nofix = the GPS device had no fix. sps = Standard
    Positioning Service; before May 2000 it was affected by Selective
    Availability degradation. dgps = Differential GPS; fix aided by
    ground-based station corrections. pps = Precise Positioning Service;
    accuracy not affected by Selective Availability, provided encrypted.
    rtk = Real Time Kinematic with fixed integers. frtk = Real Time
    Kinematic with floating integers. estimated = Estimated mode (dead
    reckoning). manual = fix was entered manually. simulator = the GPS
    device is operating in simulation mode, it had no real GPS fix.
    </documentation></annotation>
    <restriction base="string">
      <enumeration value="nofix" />
      <enumeration value="sps" />
      <enumeration value="dgps" />
      <enumeration value="pps" />
      <enumeration value="rtk" />
      <enumeration value="frtk" />
      <enumeration value="estimated" />
      <enumeration value="manual" />
      <enumeration value="simulator" />
    </restriction>
  </simpleType>

  <complexType name="satdataType">
    <annotation><documentation>
    Satellite information. If satellite information is logged, "sid"
    (Station ID) and "inuse" (if the station was used to compute the fix)
    are always logged. elevation = elevation above the horizon of the
    satellite, in degrees. azimuth = the angle between true north and the
    satellite, in degrees. snr = signal to noise ratio.
    </documentation></annotation>
    <sequence>
      <element name="elevation" type="mtk:elevationType" minOccurs="0" />
      <element name="azimuth"   type="mtk:azimuthType"   minOccurs="0" />
      <element name="snr"       type="integer"           minOccurs="0" />
    </sequence>
    <attribute name="sid"       type="unsignedByte"      use="required" />
    <attribute name="inuse"     type="boolean"           use="required" />
  </complexType>

  <simpleType name="elevationType">
    <restriction base="decimal">
      <minInclusive value="-90.0"/>
      <maxInclusive value="90.0"/>
    </restriction>
  </simpleType>

  <simpleType name="azimuthType">
    <restriction base="decimal">
      <minInclusive value="0.0"/>
      <maxExclusive value="360.0"/>
    </restriction>
  </simpleType>

  <simpleType name="msecType">
    <restriction base="nonNegativeInteger">
      <maxInclusive value="999" />
    </restriction>
  </simpleType>

  <complexType name="extensionsType">
    <sequence>
      <any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded">
      </any>
    </sequence>
  </complexType>

</schema>