Calculate Journeys

Available in big data analytics.

The Calculate Journeys tool analyzes point-based observations of moving entities and generates either journeys or dwell locations based on user-defined distance and time span tolerances.

Examples

The following are example uses of the Calculate Journeys tool:

• A shipping company wants to better understand ship movement to identify the routes ships have taken, the distance traveled in each journey, and the mean speed for that journey. You can use Calculate Journeys to generate polyline journeys containing this information as well as additional attributes regarding start and end dwell locations.
• A transportation department is monitoring vehicle movement to identify dwell locations. You can use the Calculate Journeys tool to identify dwell locations where vehicles have not exceeded a certain speed threshold.

Usage notes

Keep the following in mind when working with the Calculate Journeys tool:

• The Track ID and Start Time key fields must be identified on the input layer to use this tool.
• When using the Calculate Journeys tool, you must choose whether to generate journeys or dwell locations. If you want to generate both, configure two instances of the Calculate Journeys tool with two separate outputs.
• If you generate journeys, the output will be a polyline layer. If you generate dwell locations, the output will be a point layer.
• The values in the Distance Tolerance and Time Span Tolerance parameters are combined to form a speed threshold. This speed threshold is used to identify dwell locations.
  • When a track's speed is below the defined speed threshold (distance tolerance divided by time span tolerance), a resulting journey polyline ends and a dwell location is identified.
  • The Minimum Observation Duration and Minimum Observation Distance parameters designate the minimum required duration or distance between individual sequential features to identify the start of a dwell feature.
  • You can use the Minimum Observation Duration and Minimum Observation Distance parameters to protect against situations in which sequential track features are very close together in time or distance and you do not want the journey polyline to be split and a dwell to be identified. For example, if the track has a feature with the same geometry and is one second apart from the prior feature, a minimum observation duration of five seconds will require sequential track points to be at least five seconds apart and for the feature to be below the defined speed threshold to identify a dwell.
• When generating journeys, you must choose whether to include gaps. If chosen, gaps are created as a type of journey in the output.
• You can calculate additional statistics using the Summary Fields parameter. The summary fields statistics that are available depend on the field type you are summarizing. A string attribute field can use the Any, Count, and Count Distinct statistics. A numeric attribute field can use the Any, Count, Count Distinct, Sum, Sum of Squares, Min, Max, Range, Variance, and Standard Deviation statistics. A date attribute field can use the Any, Count, Min, Max, and Range statistics.

Parameters

The following are the parameters for the Calculate Journeys tool:

Parameter	Description	Data type
Input Layer	The point features for which either journeys or dwell locations will be calculated.	Features
Distance Tolerance	The distance tolerance value that will be used to determine dwell locations. The values in the Distance Tolerance and Time Span Tolerance parameters are combined to form a speed threshold.	String
Time Span Tolerance	The time span tolerance value that will be used to determine dwell locations. The values in the Distance Tolerance and Time Span Tolerance parameters are combined to form a speed threshold.	String
Output	Specifies whether to return the journeys (line segments) or the dwell locations (points) from the journey analysis.	String
TRACK_ID Fields	You must select the fields to uniquely identify features that will be processed. This parameter will be automatically populated if a Track ID key field has been set on the input layer.	String
Method	Specifies whether the distance calculation method will be set to Geodesic or Planar (Euclidean).	String
Include Gaps	Specifies whether to include gaps as a type of journey in the output. This parameter only applies when an output type of Journeys (line segments) is set.	Boolean
Gap Duration	The tolerance for determination of gaps between observations. Sequential observations farther apart than this time span will be considered a gap, and the previous journey will terminate at the start of the gap. This parameter only applies when an Output type of Journeys (line segments) is set.	String
Minimum Observation Duration	The minimum duration needed between a point and its previous track point for the current point to be labeled as an idle point and break a journey polyline. For example, if the track has a feature with the same geometry and is one second apart from the prior feature, a minimum observation duration of five seconds will require sequential track points to be at least five seconds apart and for the feature to be below the defined speed threshold to identify a dwell.	String
Minimum Observation Distance	The minimum distance needed between a point and its previous track point for the current point to be labeled as an idle point and break a journey polyline. For example, if the track has a feature with geometry one inch away from the prior observation and is one second apart from the prior feature, a minimum observation distance of three inches will require sequential track points to be at least three inches apart and for the feature to be below the defined speed threshold to identify a dwell.	String
Summary Fields	The statistics that will be calculated for specified fields. Different statistics are available depending on whether the specified field is a string, numeric, or date field. Any—A sample string from a field of type string. Count—Calculates the number of nonnull values. It can be used on numeric fields or strings. The count of [null, 0, 2] is 2. Count Distinct—Calculates the number of distinct, nonnull values. It can be used on numeric fields or strings. The count distinct result of [null, 4, 3, 4] is 2. Sum—The sum of numeric values in a field. The sum of [null, 1, 3] is 4. Sum of Squares—The sum, over all observations, of the squared differences of each observation from the overall mean. The sum of squares of [null, 2.2, 3.1, 4.7] is 3.206. Min—The minimum value of a numeric field. The minimum of [0, 2, null] is 0. Max—The maximum value of a numeric field. The maximum value of [0, 2, null] is 2. Mean—The mean of numeric values. The mean of [0, 2, null] is 1. Range—The range of a numeric field. This is calculated as the minimum value subtracted from the maximum value. The range of [0, null, 1] is 1. The range of [null, 4] is 0. Variance—The variance of a numeric field in a track. The variance of [1] is null. The variance of [null, 1, 1, 1] is 1. Standard Deviation—The standard deviation of a numeric field. The standard deviation of [1] is null. The standard deviation of [null, 1, 1, 1] is 1.	String

Output layer

The output layer will contain the Track ID field of the input observations as well as a variety of attributes. The attributes present on the output depend on the value chosen for the Outputparameter (Journeys or Dwell Locations).

Journeys output layer attributes

Field name	Description	Field type
TRACK_ID	The Track ID key field used for processing.	any
JourneyId	A sequentially numbered ID value for the journey. The first journey for a given track is 1, the second journey is 2, and so forth. These IDs are used as the basis for the PreviousJourneyId and NextJourneyId attributes.	Int32
JourneyType	Specifies whether the line segment is a journey or a gap.	String
JourneyStartTime	The start time of the journey. If the journey begins at a dwell location, the start time is the time of the latest feature in the dwell location.	Date
JourneyEndTime	The end time of the journey. If the journey ends at a dwell location, the start time is the time of the earliest feature in the dwell location.	Date
JourneyDuration	The amount of time in milliseconds between the start and end time of the journey.	Float64
JourneyDistanceTraveled	The distance traveled along the journey. If the journey begins at a dwell location, the x,y coordinates of the dwell centroid are used for the journey's first point, and likewise for the end location if the journey ends in a dwell.	Float64
JourneyMeanSpeed	The mean speed of the journey (JourneyDistanceTraveled value divided by the JourneyDuration value).	Float64
JourneyObservationCount	The number of observations that make up the journey.	Float64
PreviousJourneyId	The ID of the journey immediately before the journey.	Float64
NextJourneyId	The ID of the journey immediately after the journey.	Int32
StartDwellX	The x-coordinate of the centroid of the observations that make up the dwell location at the beginning of the journey. This attribute is null if the journey began based on a gap.	Float64
StartDwellY	The y-coordinate of the centroid of the observations that make up the dwell location at the beginning of the journey. This attribute is null if the journey began based on a gap.	Float64
StartDwellStartTime	The time stamp of the earliest point in the group of points that define the dwell.	Date
StartDwellEndTime	The time stamp of the latest point in the group of points that define the dwell.	Date
StartDwellDuration	The duration (in milliseconds) of the dwell at the beginning of the journey.	Float64
StartDwellMeanDistance	The mean distance, of any point participating in the dwell, from the centroid of the dwell.	Float64
StartDwellObservationCount	The number of observations that make up the dwell.	Float64
EndDwellX	The x-coordinate of the centroid of the observations that make up the dwell location at the end of the journey. This attribute is null if the journey ends based on a gap.	Float64
EndDwellY	The y-coordinate of the centroid of the observations that make up the dwell location at the end of the journey. This attribute is null if the journey ends based on a gap.	Float64
EndDwellStartTime	The time stamp of the earliest point in the group of points that define the dwell.	Date
EndDwellEndTime	The time stamp of the latest point in the group of points that define the dwell.	Date
EndDwellDuration	The duration (in milliseconds) of the dwell at the end of the journey.	Float64
EndDwellMeanDistance	The mean distance, of any point participating in the dwell, from the centroid of the dwell.	Float64
EndDwellObservationCount	The number of observations that make up the dwell.	Float64

Dwell locations output layer attributes

Field name	Description	Field type
TRACK_ID	The Track ID key field used for processing.	any
DwellObservationCount	The number of observations that make up the dwell.	Float64
DwellDuration	The duration (in milliseconds) of the dwell.	Float64
DwellStartTime	The time stamp of the earliest point in the group of points that define the dwell.	Date
DwellEndTime	The time stamp of the latest point in the group of points that define the dwell.	Date
DwellMeanDistance	The mean distance, of any point participating in the dwell, from the centroid of the dwell.	Float64
DwellX	The x-coordinate of the centroid of the observations that make up the dwell location.	Float64
DwellY	The y-coordinate of the centroid of the observations that make up the dwell location.	Float64