The chart type Value over time shows the values of properties in an observation property structure over time (using the sampling timestamp of the observation). The chart can picture observation data from any number of features of any type as long as the observation property structure contains a numeric or quantity property on level 0.

When displaying quantity properties the chart assumes that the values of the shown property are all expressed in the same unit. The unit is derived from the first shown observation. If a feature contains data in different units you need to process the data first.

When displaying numeric properties the unit displayed in the chart is derived from the feature property settings for the property drawn.

This chart type allows any number of pins typed with different feature types, each pin can connect any number of features of the same feature type. Each feature connected to a pin is presented as separate time series.