Understanding the following list of terms is essential for having a complete understanding of the ArcGIS Tracking Analyst extension.
A feature layer that is used with the ArcGIS Tracking Analyst extension. Tracking Analyst provides tools for creating a tracking layer from a feature class or shapefile. A real-time tracking layer can also be created from a tracking service.
A connection to Esri Tracking Server. Esri Tracking Server is a separate product that provides real-time data feeds to ArcGIS for Desktop in the form of tracking services. A connection to a single Esri Tracking Server can contain multiple tracking services.
A real-time data feed that is published by Esri Tracking Server and subscribed to by a client application. Two client applications, ArcMap and ArcGlobe, are included in ArcGIS for Desktop.
Observation (also known as an event)
A set of measured values for an entity at a specific point in time. For an observation to be used for tracking, it must have an associated time, referred to as the observation time. A tracking layer contains a set of observations.
An entity being tracked.
A track is a collection of observations that belong to the same object. A moving object, such as a car, can have a track that shows the locations of the car over the past hour. A stationary object can also have a track. An example of this is a collection of temperature measurements from a stationary weather sensor. In any case, a track is formed by aggregating the observations for a single entity with a single Track ID.
A field that uniquely identifies individual tracks, or objects, in a tracking layer.
A line connecting the observations in a track. Track lines are useful for depicting the approximate path of an entity. It's important to understand that the track line is only an estimation of the entity's true path based on the data that is available. A track line is not a feature in a tracking layer, so it cannot be selected or used as input for a geoprocessing tool.
A period of time for which tracking events are displayed on the map. Tracking Analyst also provides the ability to modify the symbology used for events that fall within the time window.
Custom processing that occurs when a tracking event meets the conditions of the action's trigger. Layer actions are defined for a tracking layer. Service actions are defined for a real-time tracking service.
A set of conditions that must be met by a tracking event in order for a corresponding action to execute. Triggers can be constructed from attribute or location conditions, or a combination of both.