Multistation, DataChoice for sensors

gistfile1.txt

<om:result>
  <swe2:DataStream>
      <swe2:DataRecord>
        <swe2:field name="stationID">
          <swe2:Text definition="http://mmisw.org/ont/ioos/definition/stationID">
            <swe2:value>urn:ioos:station:wmo:41001</swe2:value>
          </swe2:Text>
        </swe2:field>
        <swe2:field name="location">
          <swe2:Vector definition="http://www.opengis.net/def/property/OGC/0/PlatformLocation"
            referenceFrame="http://www.opengis.net/def/crs/EPSG/0/4326">
            <swe2:coordinate name="latitude">
              <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/latitude">
                <swe2:uom code="deg"/>
                <swe2:value>32.5</swe2:value>
              </swe2:Quantity>
            </swe2:coordinate>
            <swe2:coordinate name="longitude">
              <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/longitude">
                <swe2:uom code="deg"/>
                <swe2:value>-78.5</swe2:value>
              </swe2:Quantity>
            </swe2:coordinate>
          </swe2:Vector>
        </swe2:field>
        <swe2:field name="time">
          <swe2:Time definition="http://www.opengis.net/def/property/OGC/0/SamplingTime">
            <swe2:uom xlink:href="http://www.opengis.net/def/uom/ISO-8601/0/Gregorian"/>
          </swe2:Time>
        </swe2:field>
        
        <swe2:field name="sensorData">
          <swe2:DataChoice>
            <swe2:item name="sensor1">
              <swe2:DataRecord>
                <swe2:field name="sensorID">
                  <swe2:Text definition="http://mmisw.org/ont/ioos/definition/sensorID">
                    <swe2:value>urn:ioos:station:wmo:41001:sensor1</swe2:value>
                  </swe2:Text>
                </swe2:field>
                <swe2:field name="altitude">
                  <!-- COMMENT: Looks like the alt swe:Quantity can have a referenceFrame attribute:
                    <swe:Quantity definition="http://mmisw.org/ont/cf/parameter/altitude" 
                    referenceFrame="http://www.opengis.net/def/crs/EPSG/0/4326">
                    This attribute could point to a vertical datum. Look into Oostethys discussions
                    on vertical datums, and Issue 16 -->
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/altitude" referenceFrame="http://www.opengis.net/def/crs/EPSG/0/4326">
                    <swe2:uom code="m"/>
                    <swe2:value>5</swe2:value>
                  </swe2:Quantity>
                </swe2:field>
                <!-- The "data" fields follow (measured quantities/properties) -->
                <swe2:field name="air_temperature">
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/air_temperature">
                    <swe2:uom code="Celsius"/>
                  </swe2:Quantity>
                </swe2:field>
                <swe2:field name="wind_speed">
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/wind_speed">
                    <swe2:uom code="m/s"/>
                  </swe2:Quantity>
                </swe2:field>
                <swe2:field name="wind_to_direction">
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/wind_to_direction">
                    <swe2:uom code="degrees"/>
                  </swe2:Quantity>
                </swe2:field>
              </swe2:DataRecord>
            </swe2:item>
            
            <!-- ===========================================================
              custom swe:item field definitions
              =========================================================== -->
            <swe2:item name="sensor2">
              <swe2:DataRecord>
                <!-- sensorID and the "Z" dimension (eg, altitude) -->
                <swe2:field name="sensorID">
                  <swe2:Text definition="http://mmisw.org/ont/ioos/definition/sensorID">
                    <swe2:value>urn:ioos:station:wmo:41001:sensor2</swe2:value>
                  </swe2:Text>
                </swe2:field>
                <swe2:field name="altitude">
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/altitude" referenceFrame="http://www.opengis.net/def/crs/EPSG/0/4326">
                    <swe2:uom code="m"/>
                    <swe2:value>-2</swe2:value>
                  </swe2:Quantity>
                </swe2:field>
                <!-- The "data" fields follow (measured quantities/properties) -->
                <swe2:field name="sea_water_temperature">
                  <swe2:Quantity definition="http://mmisw.org/ont/cf/parameter/sea_water_temperature">
                    <swe2:uom code="Celsius"/>
                  </swe2:Quantity>
                </swe2:field>
                <swe2:field name="dissolved_oxygen">
                  <swe2:Quantity definition="http://mmisw.org/ont/ioos/parameter/dissolved_oxygen">
                    <swe2:uom code="mg/L"/>
                  </swe2:Quantity>
                </swe2:field>
              </swe2:DataRecord>
            </swe2:item>
          </swe2:DataChoice>
          
        </swe2:field>
      </swe2:DataRecord>
    </swe2:elementType>
    
    <!-- ===========================================================
        SWE encoding and data values
        swe:encoding *must* be always specified exactly as described below,
        to avoid the need to have fully general parsers that interpret
        swe:TextEncoding. That is, parsers may hard-code this particular
        swe:TextEncoding specification.
        =========================================================== -->
    <swe2:encoding>
      <swe2:TextEncoding decimalSeparator="." tokenSeparator="," blockSeparator="\n"/>
    </swe2:encoding>
    <swe2:values> 
      2009-05-23T00:00:00Z,sensor1,15.4,2.0,280
      2009-05-23T01:00:00Z,sensor1,15.8,1.8,121
      2009-05-23T02:00:00Z,sensor1,15.6,1.0,1.42
      2009-05-23T00:00:00Z,sensor2,5.6,8.0
      2009-05-23T01:00:00Z,sensor2,5.8,8.2
      2009-05-23T02:00:00Z,sensor2,5.7,8.5
    </swe2:values>
  </swe2:DataStream>
</om:result>