linear referencing an introduction heather mccracken & derek law esri redlands uc 2009 tech...

Linear ReferencingLinear ReferencingAn IntroductionAn Introduction

Heather McCracken & Derek LawHeather McCracken & Derek LawESRI RedlandsESRI Redlands

UC 2009 Tech SessionsUC 2009 Tech Sessions 11

OutlineOutline

• Fundamental conceptsFundamental concepts• Terminology in ArcGISTerminology in ArcGIS• Query & analysis operationsQuery & analysis operations• Creating & maintaining routesCreating & maintaining routes• SummarySummary


OutlineOutline

• Fundamental conceptsFundamental concepts– Define linear referencingDefine linear referencing

– Application examplesApplication examples

• Terminology in ArcGISTerminology in ArcGIS• Query & analysis operationsQuery & analysis operations• Creating & maintaining routesCreating & maintaining routes• SummarySummary


What is linear referencing?What is linear referencing?

• Method of storing geographic features by usingMethod of storing geographic features by usingrelative positionsrelative positions along a measured line feature along a measured line feature


A307 is 100 miles long. Where is mile 60?A307 is 100 miles long. Where is mile 60?

B7 B7

A307

A307

A45

A45

D23

D23 F478

F478

AA

Why use linear referencing?Why use linear referencing?

• Intuitive way to model relative locations alongIntuitive way to model relative locations alonglinear featureslinear features

– E.g., The concrete road surface starts at mile 5,E.g., The concrete road surface starts at mile 5,NOT The concrete road surface starts at NOT The concrete road surface starts at 3030oo40’25’’N, 9640’25’’N, 96oo22’32’’W22’32’’W

• Enables the association of multiple sets of attributes to portions Enables the association of multiple sets of attributes to portions of linear features without segmenting the underlying line each of linear features without segmenting the underlying line each time attribute values changetime attribute values change


mile 5mile 5

3030oo40’25’’N, 9640’25’’N, 96oo22’32’’W22’32’’W

AA

Features using a linear system of measureFeatures using a linear system of measure

• Feature’s location determined using a linear system of measure Feature’s location determined using a linear system of measure values, instead of using x,y coordinatesvalues, instead of using x,y coordinates


Main St15

40 60 8095

20

Accident occurred 50

meters along Main St.

Features containing one-to-many relationshipsFeatures containing one-to-many relationships

• Two or more pieces of information associated with the same Two or more pieces of information associated with the same location on a linelocation on a line


Railroad

Accidents

Speed45 35 45 55

0 20 40 60 80 100

River

Salmon habitat

Gradient Rapid Slow

Coho Coho/King

0 100

200

300

400500 600

TransportationTransportation

Natural resourcesNatural resources

Features containing frequently segmented dataFeatures containing frequently segmented data

• Some types of features have attributes that change frequentlySome types of features have attributes that change frequently


concrete asphaltMaterial

Qualityfair good poor

Main St.15

40 60 8095

20

OutlineOutline

• Fundamental conceptsFundamental concepts• Terminology in ArcGISTerminology in ArcGIS

– RoutesRoutes

– MeasuresMeasures

– EventsEvents

– Dynamic segmentationDynamic segmentation

• Query & analysis operationsQuery & analysis operations• Creating & maintaining routesCreating & maintaining routes• SummarySummary


RoutesRoutes

• Linear features – in a polyline feature classLinear features – in a polyline feature class• Must have an Must have an identifieridentifier & & measurement systemmeasurement system• Store in a geodatabase, shapefile, or coverageStore in a geodatabase, shapefile, or coverage


Linear feature

Unique identifier

Route 711081

Route geometry and what can they modelRoute geometry and what can they model

• Route geometryRoute geometry

• Routes can modelRoutes can model


Single part polyline Multi-part polyline

Looping 180-degree turnsBranching

Routes in ArcMapRoutes in ArcMap

• Layer properties > Route tabLayer properties > Route tab• Route IdentifierRoute Identifier

– Uniquely identifies each routeUniquely identifies each route

– Used by all other linear referencing dialogs in ArcGISUsed by all other linear referencing dialogs in ArcGIS


MeasuresMeasures

• The distance along a route from an originThe distance along a route from an origin– Can be miles, meters, feet, time Can be miles, meters, feet, time

• Do not have to be the same units as the x,y coordinatesDo not have to be the same units as the x,y coordinates

– Can increase, remain constant, or decreaseCan increase, remain constant, or decrease

• Route vertices store measure values (M)Route vertices store measure values (M)• NaN (unknown) measures may exist NaN (unknown) measures may exist

– Not a NumberNot a Number


M at every vertex

0.0

1.2

NaN3.7 4.8

4.2

Route locationsRoute locations

• Use a route identifier to locate the appropriate routeUse a route identifier to locate the appropriate route• 2 types2 types

– PointPoint (uses a single measure value) (uses a single measure value)

– Discrete location on a routeDiscrete location on a route

– LineLine (uses (uses from-from- and and to- to- measure values)measure values)

– Describe a portion of a routeDescribe a portion of a route


I10

Accident occurred at mile 23Accident occurred at mile 23

Kenai River

Salmon found between mile 10 and mile 20

Salmon found between mile 10 and mile 20

Event tablesEvent tables

• Route locations thematically stored in tables are called “Route locations thematically stored in tables are called “route route eventsevents” or simply “” or simply “eventsevents””

• 2 types2 types– PointPoint event table event table

• E.g., Accidents, Sample sitesE.g., Accidents, Sample sites

– LineLine event table event table• E.g., Pavement conditions, Riverbank compositionE.g., Pavement conditions, Riverbank composition

• An event can be any type of table supported by ArcGISAn event can be any type of table supported by ArcGIS


Point event tablesPoint event tables

• Two required fieldsTwo required fields– Route IDRoute ID identifies route on which event is located identifies route on which event is located

– MeasureMeasure is the event’s location on the route is the event’s location on the route

• Other attributes about the eventOther attributes about the event


Route location Attributes

Route 1

4

14

34

45

53

0

60

Line event tablesLine event tables

• Three required fieldsThree required fields– Route IDRoute ID identifies route on which event is located identifies route on which event is located

– From MeasureFrom Measure and and To MeasureTo Measure define beginning and end of line event define beginning and end of line event

• Other attributes about the eventOther attributes about the event


Route location AttributesRoute 48

0

25

0

60

AA

Dynamic segmentationDynamic segmentation

• Computing the location of events on routesComputing the location of events on routes– Event locations can change dynamicallyEvent locations can change dynamically

• Locations are interpolatedLocations are interpolated

• Use the Use the MakeRouteEventLayerMakeRouteEventLayer GP tool GP tool


A307 10.2A307A307F478F478A45A45

25.62.59.53.27.1

1103244

ACCTYPEMILE

6543210

OID RKEY

15.5

A45

A307

B7

D23

F478

Event layers are feature layersEvent layers are feature layers

• Created by the dynamic segmentation processCreated by the dynamic segmentation process– Underlying route is not fragmentedUnderlying route is not fragmented

• Event layers behave just like other feature layersEvent layers behave just like other feature layers– Display using custom symbologyDisplay using custom symbology

– Perform GIS analysis Perform GIS analysis

– Save as a layer fileSave as a layer file

– Export to feature classExport to feature class


Routes, measures, eventsRoutes, measures, events& dynamic segmentation& dynamic segmentation


Demo 1Demo 1

OutlineOutline

• Fundamental conceptsFundamental concepts• Terminology in ArcGISTerminology in ArcGIS• Query & analysis operationsQuery & analysis operations

– Route queryRoute query

– Route symbolization optionsRoute symbolization options

– Route events analysisRoute events analysis

• Creating & maintaining routesCreating & maintaining routes• SummarySummary


Find and Identify route locationsFind and Identify route locations

Find:Find: Query a map using Query a map using a route locationa route location


Identify Route Locations:Identify Route Locations: Click on map to determine Click on map to determine route locations route locations

AA

Route: 13000C00158

Measure: 0.5

HatchingHatching

• Line or point marker symbols placed at an interval along a routeLine or point marker symbols placed at an interval along a route– DistanceDistance

• E.g., meters, feetE.g., meters, feet

– Non-distanceNon-distance• E.g, sample sitesE.g, sample sites

• Create & modify hatch Create & modify hatch styles via style managerstyles via style manager

• Import hatches from a Import hatches from a layer file (.lyr)layer file (.lyr)

• Convert hatches to graphicsConvert hatches to graphics


Seismic linesSeismic lines

HatchHatchHatchHatch

Route event analysis toolsRoute event analysis tools

• Overlay eventsOverlay events• Dissolve/concatenate eventsDissolve/concatenate events• Transform eventsTransform events• Locate points & polygonsLocate points & polygons

along routesalong routes


Overlay eventsOverlay events

• Logical union or intersection of two input event tablesLogical union or intersection of two input event tables

– Creates new event table with attributes from both tablesCreates new event table with attributes from both tables

• Non-geometric way of performing– Line-on-line, line-on-point, & point-on-point overlaysLine-on-line, line-on-point, & point-on-point overlays


Accident countAccident count

Speed limitSpeed limit

Pavement typePavement type

Skid valuesSkid values

Asphalt

35 45 55

4535 65

Asphalt Concrete

34 30 32

25

Result

GIS Query:Accident count > 50 Speed limit = 65 Pavement = Concrete Skid value >= 30

GIS Query:Accident count > 50 Speed limit = 65 Pavement = Concrete Skid value >= 30

AA

Dissolve/concatenate eventsDissolve/concatenate events


• Concatenate:Concatenate: remove redundant information from a tableremove redundant information from a table• Concatenate:Concatenate: remove redundant information from a tableremove redundant information from a table

• Dissolve:Dissolve: split tables having more than one descriptive attributesplit tables having more than one descriptive attribute• Dissolve:Dissolve: split tables having more than one descriptive attributesplit tables having more than one descriptive attribute

Transform eventsTransform events

• Transforms event measures from one route feature Transforms event measures from one route feature class to anotherclass to another– Route feature classes can be of different measure systems Route feature classes can be of different measure systems

(e.g., time & length)(e.g., time & length)• Creates a new event tableCreates a new event table• Can update events after road realignmentsCan update events after road realignments


Locate points along routesLocate points along routes

• Create a point events table by locating the points Create a point events table by locating the points along a routealong a route

• Preserves point attributesPreserves point attributes• Route-to-point distance can be createdRoute-to-point distance can be created


Route locationPoint

attributes

Optional distance field

Locate polygons along routesLocate polygons along routes

• Creates a line events table from the intersection of routes with Creates a line events table from the intersection of routes with polygonspolygons

• Preserves polygon attributesPreserves polygon attributes


Route location Polygon attributes

Find & identify route locationsFind & identify route locationsRoute event analysisRoute event analysis


Demo 2Demo 2

OutlineOutline

• Fundamental conceptsFundamental concepts• Terminology in ArcGISTerminology in ArcGIS• Query & analysis operationsQuery & analysis operations• Creating & maintaining routesCreating & maintaining routes

– Creating routesCreating routes

– Calibrating routesCalibrating routes

– Editing routesEditing routes

• SummarySummary


Creating routesCreating routes

• Routes are created byRoutes are created by– Merging linear features based on common identifiersMerging linear features based on common identifiers

• E.g., route IDE.g., route ID

– Setting measures based on one or two fields Setting measures based on one or two fields

• Create routesCreate routes– By creating a new empty feature class & loading dataBy creating a new empty feature class & loading data

– By creating a new route feature class from existing line featuresBy creating a new route feature class from existing line features

– By converting an existing route feature classBy converting an existing route feature class

• MethodsMethods– ArcToolbox (ArcToolbox (CreateRoutesCreateRoutes & & CalibrateRoutesCalibrateRoutes GP tools) GP tools)

– ArcCatalogArcCatalog

– ArcMapArcMap


Create a Route Feature Class from ScratchCreate a Route Feature Class from Scratch

• Follow standard procedures for creating a feature classFollow standard procedures for creating a feature class


Enable M storageEnable M storage

Set geometry typeSet geometry type

Define route identifier field

Define route identifier field

Create a route feature class from existing linesCreate a route feature class from existing lines


• CreateRoutes GP toolCreateRoutes GP tool

Input featuresInput features

Route ID fieldRoute ID field

Output featuresOutput features

Measure field(s) or Geometric Length

Measure field(s) or Geometric Length

Calibrate route feature classCalibrate route feature class

• Setting a route’s measurement systemSetting a route’s measurement system


CalibrateCalibrate

10

0.0

55.6510

1525

30Points with measures

Points with measures

Existing vertexExisting vertex

28.4

35.25

1015

20 2530

1.1

New vertices createdwith interpolated

measures

New vertices createdwith interpolated

measuresExisting vertex’s

measure is interpolated

Existing vertex’s

measure is interpolated

ExtrapolationExtrapolation

ExtrapolationExtrapolation

AA

Editing routesEditing routes


Sketch PropertiesSketch Properties

Tasks for linear referencingTasks for linear referencing

Route Editing toolbarRoute Editing toolbarRoute Editing toolbarRoute Editing toolbar

Define line portion

Define line portion

Make RouteMake Route

Calibrate Route

Calibrate Route

• Edit routes just like any polylineEdit routes just like any polyline– Extend, delete, split, etcExtend, delete, split, etc Editing toolbarEditing toolbarEditing toolbarEditing toolbar

AA

Create a route feature class,Create a route feature class,then calibrate its M valuesthen calibrate its M values


Demo 3Demo 3

SummarySummary

• Fundamental conceptsFundamental concepts– Defined linear referencing and its applicationsDefined linear referencing and its applications

• Terminology in ArcGISTerminology in ArcGIS– Routes, measures, events, & dynamic segmentationRoutes, measures, events, & dynamic segmentation

• Query & analysis operationsQuery & analysis operations– Simple querying, symbology, & analysis toolsSimple querying, symbology, & analysis tools

• Creating & maintaining routesCreating & maintaining routes– How to create, calibration, & editingHow to create, calibration, & editing

• Please complete review surveysPlease complete review surveys


Questions?Questions?


linear referencing an introduction heather mccracken & derek law esri redlands uc 2009 tech...

Documents

routes linear features

tech sessions

portions of linear features

line uc

geographic features

routes summarysummary

coverage uc

measured line feature