SensorML 2.0 Examples

Analog Detector

An analog detector is a PhysicalComponent that converts from one observable property to another observable property. This is in contrast to most digital detectors which typically convert from an observable property to some digital number representing a measure of that observable property. Thus while a digital detector typically takes an ObservableProperty as its inputs and outputs a Quantity, an analog detector typically takes ObservableProperty elements for both its input and output.

The example below is a simple thermistor which converts temperature to an electrical resistance which must then be measure by another device (such as a digital voltmeter). The output carries no units of measure since its is an ObservableProperty, but a calibration curve is typically provided which relates measured resistance to temperature. This is provided as a parameter in the example.

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<?xml version="1.0" encoding="UTF-8"?>
<sml:PhysicalComponent gml:id="Davis7817" xml:lang="en"
xmlns:sml="http://www.opengis.net/sensorml/2.0"
xmlns:swe="http://www.opengis.net/swe/2.0"
 xmlns:gml="http://www.opengis.net/gml/3.2"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:xlink="http://www.w3.org/1999/xlink"
 xsi:schemaLocation="http://www.opengis.net/sensorml/2.0 http://schemas.opengis.net/sensorml/2.0/sensorML.xsd">
    <!-- ================================================= -->
    <!--                  Component Description               -->
    <!-- ================================================= -->
    <gml:description>a simplet thermistor that outputs resistance as a function of temperature</gml:description>
    <gml:identifier codeSpace="uniqueID">urn:davisweather:7817</gml:identifier>
    <gml:name>Davis_7817 Thermometer</gml:name>
    <!-- metadata left out for brevity sake  -->
    <!--~~~~~~~~~~~~~-->
    <!-- Detector Inputs-->
    <!--~~~~~~~~~~~~~-->
    <!-- note: in most cases, a detector’s input will be an observableProperty and its output a measured digital value
            (e.g. Quantity)  -->
    <sml:inputs>
        <sml:InputList>
            <sml:input name="temperature">
                <sml:ObservableProperty definition="http://sweet.jpl.nasa.gov/2.3/propTemperature.owl#Temperature"/>
            </sml:input>
        </sml:InputList>
    </sml:inputs>
     
    <!--~~~~~~~~~~~~~~-->
    <!-- Detector Outputs-->
    <!--~~~~~~~~~~~~~~-->
    <!-- note: in this case, the detector’s output is also an observableProperty (electrical resistance) rather than
                measured digital values -->
    <sml:outputs>
        <sml:OutputList>
            <sml:output name="electricalResistance">
                <sml:ObservableProperty definition="http://sweet.jpl.nasa.gov/2.3/propConductivity.owl#Resistance"/>
            </sml:output>
        </sml:OutputList>
    </sml:outputs>
     
    <!--~~~~~~~~~~~~~~~~~~~~~~~~~~~-->
    <!--  Temperature Response     -->
    <!--~~~~~~~~~~~~~~~~~~~~~~~~~~~-->
    <sml:parameters>
        <sml:ParameterList>
            <sml:parameter name="steadyStateCalibration">
                <swe:DataArray definition="http://sensorml.com/ont/swe/property/calibrationCurve">
                    <swe:elementCount>
                        <swe:Count>
                            <swe:value>21</swe:value>
                        </swe:Count>
                    </swe:elementCount>
                    <swe:elementType name="calibrationCurve">
                        <swe:DataRecord>
                            <swe:label>Calibration Curve</swe:label>
                            <swe:field name="temperature">
                                <swe:Quantity definition="http://sweet.jpl.nasa.gov/2.3/propTemperature.owl#Temperature">
                                    <swe:label>Temperature</swe:label>
                                    <swe:uom code="cel"/>
                                </swe:Quantity>
                            </swe:field>
                            <swe:field name="resistance">
                                <swe:Quantity definition="http://sweet.jpl.nasa.gov/2.3/propConductivity.owl#Resistance">
                                    <swe:label>Resistance</swe:label>
                                    <swe:uom code="kohm"/>
                                </swe:Quantity>
                            </swe:field>
                        </swe:DataRecord>
                    </swe:elementType>
                    <swe:encoding>
                        <swe:TextEncoding tokenSeparator=" " blockSeparator="," decimalSeparator="."/>
                    </swe:encoding>
                    <swe:values>
                        -40,328.4 -35,237.7 -30,173.9
                        -25,128.5 -20,95.89 -15,72.23
                        -10,54.89 -5,42.07 0,32.51
                        5,25.31 10,19.86 15,15.69
                        20,12.49 25,10 30,8.06 35,6.536
                        40,5.331 45,4.373 50,3.606
                        55,2.989 60,2.49
                    </swe:values>
                </swe:DataArray>
            </sml:parameter>
        </sml:ParameterList>
    </sml:parameters>
     
    <!--~~~~~~~~~~~~~~~~~~~~~~~-->
    <!--Detector Coordinate Frame-->
    <!--~~~~~~~~~~~~~~~~~~~~~~~-->
    <!-- Spatial Reference Frame -->
    <sml:localReferenceFrame>
        <sml:SpatialFrame id="THERMOMETER_FRAME">
            <sml:origin>origin is at the measuring tip of the thermistor</sml:origin>
            <sml:axis name="x">the x axis is orthogonal to z but indeterminate</sml:axis>
            <sml:axis name="y">the y axis is orthogonal to z but indeterminate</sml:axis>
            <sml:axis name="z">the z axis is along the long axis of symmetry (or shaft) of the thermistor</sml:axis>
        </sml:SpatialFrame>
    </sml:localReferenceFrame>
 
    <!--~~~~~~~~~~~~~~-->
    <!--  Method               -->
    <!--~~~~~~~~~~~~~~-->  
    <sml:method xlink:href="http://sensorml.com/def/process/detector"/>
 
</sml:PhysicalComponent>