Essential Pipeline Referencing vocabulary

Activity

Often used in the context of edit activities, which are discrete capabilities supported by ArcGIS Pipeline Referencing to edit LRS Networks. ArcGIS Pipeline Referencing supports the following edit activities: create route, extend route, realign route, cartographic realignment of route, reassign route, and retire route.

ALRS

Acronym for the Advanced Linear Referencing System, a linear referencing system implemented by ArcGIS Pipeline Referencing on the ArcGIS platform that supports multiple linear referencing methods and event measure behaviors. ALRS and LRS are used interchangeably in ArcGIS Pipeline Referencing.

Asset

In the context of linear referencing, often refers to a type of linear referenced event that represents a physical object, such as a milepost, pipe segment, or pipefitting.

Calibration point

A point feature that defines the measure for a specific location on an LRS route. ArcGIS Pipeline Referencing uses calibration points to define the measures on the routes. The measures between two calibration points on a route are derived by linear interpolation.

Centerline

A polyline feature that defines part (or all) of the geometry of an LRS route. Routes in ArcGIS Pipeline Referencing can have multiple centerlines, and routes in different networks can share centerlines.

Continuous network

A network composed of routes with continuous, uninterrupted measures that increase as you traverse the route. There are no equation points or stationing in a continuous network.

Engineering network

A network composed of multiple routes logically grouped together in lines that can increase or decrease in measure as you traverse them. Equation points are used at locations where one route ends and another route begins. Events on engineering networks can span routes. In ArcGIS Pipeline Referencing, an engineering network is called an LRS Line Network.

Event

In the context of linear referencing, an event refers to data that is located by its association to an LRS route and measure location. There are two event types. Point events have a single measure along a route while linear events have a from and to measure along a route. Events are typically modeled in a database with a column for the route ID the record references, a measure column for the location on the route (two measure columns if it's a linear event), and a value (pipe coating). Additional temporal information on the time frames the event is valid can also be modeled.

An example of a point event is an anomaly location referenced on a route that occurred at measure 1000 feet on the pipe. An example of a linear event is the record of an operating pressure of 400 psi on a route from measure 0 feet to 1000 feet.

Equation

During LRS edit activities, gaps or overlaps in measures may be introduced between the adjacent routes in a Line Network. These points of discontinuity in measures between the routes are referred to as equations.

Event behavior

In the context of linear referencing and ArcGIS Pipeline Referencing, event behavior refers to the configuration that defines how event measures and route associations respond to changes or edits in the LRS Network.

ArcGIS Pipeline Referencing, based on network edits, supports the following event behaviors:

• Stay Put—Keeps events geographically fixed in a location, which may result in event measures changing on modified portions of routes
• Snap—Reassigns (or snaps) events to reassigned routes on modified portions of routes
• Move—Keeps event measures fixed, which may result in events geographically moving on modified portions of routes
• Retire—Retires events on portions of routes that change

Event Editor

A web-based event editing application included with ArcGIS Pipeline Referencing.

Interpolative LRM

A linear referencing method that determines a location by interpolating between two known measures.

Line

A continuous logical grouping of one or more routes used for a measure system, specifically used in conjunction with an LRS Line Network.

Linear network maintainer

A GIS analyst responsible for editing the ALRS.

Linear event

An event that represents a segment of a route from a starting measure (or from measure) to an ending measure (or to measure). A linear event can span multiple routes in a Line network if configured to do so, and will then also maintain a from route and to route.

LRM

Acronym for linear referencing method, a method for defining measurements along linear features for the purpose of linear referencing. Examples of LRMs include continuous stationing in continuous networks and engineering stationing in engineering networks.

LRS

Acronym for linear referencing system, the method of storing geographic locations by using relative positions along a measured linear feature. LRS and ALRS are used interchangeably in ArcGIS Pipeline Referencing.

LRS Derived Network

A network generated from a Line Network. In a Derived Network, routes that belong to the same line are merged together to create one route with a beginning measure of zero.

LRS Line Network

A logical grouping of routes to a Line where the measure may increase or decrease monotonically. This type of network supports events that span routes and also supports equations. See What is an LRS Network? for more information.

LRS Network

A collection of routes, measured to a specific LRM, in ArcGIS Pipeline Referencing.

Non-branching

A pipeline that does not divide into two or more branches of pipelines.

Measure

A location along a route based on a distance from a known point of origin.

Point event

An event that represents a single point location on a route at a specific measure.

Project stationing

A system of stationing where the starting reference station is established at the base of a project location, and all distances along the route centerline are measured from that point location.

Redline

A feature in ArcGIS Pipeline Referencing that can be added to the redline feature class and can be used to communicate desired modifications to the LRS Network. Redline features can be edited via the Event Editor web application.

Referent

A fixed location along a route that has a discrete measure value from which other locations are determined.

Referent offset

A fixed distance from a referent; it can be positive or negative.

Referent offset event

An event whose location is modeled as being a specific distance along a route relative to another event on the route.

Route

A linear LRS feature. In ArcGIS Pipeline Referencing, a route is a run of a physical pipe where measure values are strictly increasing or decreasing monotonically. Routes are polyline features that contain M measures and are built on centerlines that are polyline features that do not contain M measures.

Station

Reference points that are placed along the horizontal measurement of a route, centerline, or baseline at a regular interval. Station numbers increase from West to East or South to North based on the cardinal direction of the overall network.

Stationing

The fundamental system of measurement used by surveyors. For highway or pipeline projects, a starting reference station is first established, and all distances along the route centerline are measured from that point location. Generally, the distance between two adjoining stations along a route is 100 feet. The first station located at the beginning of the baseline is 0+00 and the next station located 100 feet away from it is 1+00. Therefore, a station number of 10+34.05 depicts 1034.05 feet (10*100 + 34.05) away from the starting station.