Terms

This topic introduces the basic concepts of Trajectory SQL.

Name	Description
Trajectory Point	A spatiotemporal object that defines the location and properties of a moving object at a specific time. The location is a 2D or 3D coordinate. The properties can have multiple fields of various types.
Trajectory Object	A high-dimensional object that contains time, space, properties, and events. It consists of a sequence of trajectory points and trajectory events.
Trajectory Timeline	A time series of values that represents the continuous progression of a trajectory.
Trajectory Spatial	A Geometry object that represents the spatial path of a trajectory. This object is usually a linestring.
Trajectory Leaf	A trajectory leaf is a trajectory point. It represents the spatial position of a moving object at a specific time.
Trajectory Attributes	The properties of a moving object at different trajectory points, such as speed and direction.
Trajectory Attribute Field	A field within the trajectory properties, such as a speed field. The number of values for an attribute field matches the number of trajectory points.
Trajectory Field Value	The value of a property field at a specific time.
Trajectory Events	An additional event that occurs during a trajectory, such as refueling, breaking down, or locking the car during a trip. An event consists of an event type ID and an event time.

Figure 1: Trajectory diagram