The data stored for each sensor can be divided into logical parts listed in table 1. A sensor is uniquely identified by its numeric sensor ID that is automatically assigned by the system for each created sensor. The Application Server does not check uniqueness of sensor names, it is up to the user to uniquely name sensors id needed.
Data part |
Description |
Identification data |
The unique ID and the name the name and the type of the sensor. Identification data is always available for feature of any feature type |
Base data |
This description of the sensor, the assignment to a sensor type and to a domain, The base data is available for sensors of any feature type. |
A Property structure instance that stores type specific data according to the sensor type of the sensor. I.e. the sensor type defines a property structure and each sensor of that type can then store one instance of that property structure to describe the sensor. Not all sensor types define a property structure for type specific data. Therefore there may be sensors that do not have type sepecific data. |
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Each sensor may store data that is valid for this sensor in specific time periods. This data is called the chronological sensor configuration. The chronological sensor configuration includes a property structure instance that stores data according to the sensor type of the sensor. |
Table 1: Data stored for a sensor
For most sensor types it is important to know the configuration of a sensor at the sampling timestamp of an observation in order to interpret the observation result. The sensor type defines the property structure that is used to describe the per observation configuration of sensors of that type. Together the data stored for the sensor and the sensor observation configuration describe the configuration of a sensor at the time of a specific observation.
The actual configuration that was in place at the time of an observation sampling is then determined by the Application Server by searching for a chronological sensor configuration entry that covers the sampling timestamp. Figure 1 shows a formal specification of the chronological sensor configuration for a specific sampling timestamp. Note that not all sensor types provide a property structure for chronological sensor configuration.
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Figure 1: Specification of the chronological sensor configuration valid for a specific observation sampling timestamp.
