ModelTimeSeries.html

<h3>Time series</h3>
<p>
    Many executions are made as parts of a time series.
    There are a number of ways these may be modeled using the SSN Ontology.
</p>
<p>
    The most explicit representation has each member of the series as an individual member of a <a
        href="#Collections">Collection</a>.
    For example <a href="#Fig-timeseries-oc"></a> shows a <a href="#SOSAObservationCollection">Collection of
        Observations</a> that has a member for each time-step in the series.
</p>
<figure id="Fig-timeseries-oc">
    <embed alt="Explicit time-series" src="./images/timeseries-oc.svg" style="width:100%" />
    <figcaption>
        Collection of observations of the same property on the same feature of interest, with each member representing a
        step in the time-series.
        <br>
        <em><a href="#Class-diagram">Explanation of the notation used in class diagrams</a></em>.
    </figcaption>
</figure>
<pre class="example turtle" data-include="./rdf/examples/timeseries-oc.ttl" data-include-format="text"></pre>

<p>
    Alternatively, the series may be represented as a single <a href="#SOSAObservation">Observation</a> whose result is
    a complex value, such as a vector or array.
    This may be indicated 'inline' as a complex literal, e.g. CSV:
</p>
<pre class="example turtle" data-include="./rdf/examples/timeseries-result-inline.ttl" data-include-format="text"></pre>
<p>
    In this example, an OGC SWE Common `DataRecord` ([[SWE-Common]], [[SWE-Common-JSON]]) is used to
    define an RDF Datatype that encodes data records encoded in CSV.
</p>

<p>
    The result of a time series observation can also be 'linked' to an external resource:
</p>
<pre class="example turtle" data-include="./rdf/examples/timeseries-result-link.ttl" data-include-format="text"></pre>

<p>
    In addition to the encodings shown above, terms from SOSA can be directly integrated into existing structures, such
    as OGC Coverages [[CoverageJSON]].
    In such cases, it is no longer necessary to provide a paired Observation.
</p>