NovaStar Data Model / Point
Points are physical or virtual "sensors" that measure or generate data values of a specific data type.
Overview
Each NovaStar point defines properties that allows timestamped data records (also called "data reports") to be associated with the point. A point can correspond to the following:
- sensor
- import
- equation output
- forecast
A point can have zero or more points, each of which collect data. The point's properties indicate to software how to ingest data.
Each point also may have:
- calibrations - to convert raw sensor value to scaled value suitable for analysis and information products
- ratings - to convert scaled value to derived values (e.g., convert accumulated precipitation from sensor to increment, storm total, and seasonal total)
Station Data Best Practices
Many point data properties are clearly defined, including selection from predefined lists or numerical values. However, in some cases, there is flexibility to define data. The following are are best practice recommendations for station data.
Point Numerical Identifier
The point numerical identifier is a unique integer value that identifies the point within NovaStar. This is not the same as the internal identifier that is used for database relationships. The numerical identifier is typically set as follows:
- For legacy ALERT stations:
- ...
- For ALERT2 stations:
- ...
- For other stations that are owned and maintained by the NovaStar system entity:
- ...
- For stations that are owned and maintained by another entity:
- ...
Point Remote Identifier
Point Sensor Identifier
Point Tag Name
The point tag name is used for data displays as an alternate to the numerical identifier and must be unique within the system. Because it is text, it is generally set to an identifier that has meaning in the data collection system:
- For legacy ALERT stations:
- ...
- For ALERT2 stations:
- ...
- For other stations that are owned and maintained by the NovaStar system entity:
- ...
- For stations that are owned and maintained by another entity:
- ...
Point Name
The point name is displayed in user interfaces and information products and should be defined as a short phrase without special characters. It typically starts with all or part of the station name followed by the data type being collected at the point. The following table lists recommendations. Using a regional entity allows stations in multiple jurisdictions to be easily sorted in lists.
Point Name Recommendations
| System Type | Recommended Point Name |
|---|---|
| All systems. | Station Name - Data Type |
| All systems. | Station Name - Rain |
| All systems. | Station Name - Water Level PT |
| All systems. | Station Name - Battery |
If a station is located at a confluence and measures data for more than one stream, it may collect data from two or more points with name that is otherwise the same. In this case, it may be necessary to add the confluence name to the point name, for example:
Station Name - Water Level (ABC Creek)
Station Name - Water Level (XYZ Creek)
If a station has multiple similar sensors, it may be necessary to add the sensor type or manufacturer to the point name, for example:
Station Name - Water Level (PT)
Station Name - Water Level (Radar)
Point Description
The point description provides a longer description and may contain Property=Value strings to define point properties. The description is useful for describing the sensor configuration, for example the location and datum for water elevation sensor. See the data web services documentation for standard description property names. The following are examples of property descriptions.
Elevation datum is channel bottom.
Survey refernce point is top of outlet, point retired in 2020.
Out of Service
The point "out of service" value indicates whether a point is out of service. The value should be set to true when a point is out of service for the following reasons:
- maintenance that requires multiple days to fix a sensor (e.g., lightning strike, equipment failure)
- winterized station/sensor
- retired station/point (see also description properties)