1. LINEAR REFERENCING In Arc GIS Version 9.3

2. Institute of Geology, University of the PunjabTuesday, January 28, 2014Linear Referencing Presented To: Sir. Numan Ashraf Submitted By: Abdul Haseeb Ahson Atiqa Ijaz Khan01 022 3. Institute of Geology, University of the PunjabTable Of Contents1. What is Linear Referencing? 2. Implementation in Arc GIS 3. Why Use Linear Referencing? 4. Route 5. Event Table 6. Dynamic Segmentation7. Working with Arc GIS 8. Summary 9. ReferencesTuesday, January 28, 20143 4. 4What Is Linear Referencing? 1. It is the method of storing geographic locations by using relative positions along a measured linear feature. 2. In linear referencing, location is given in terms of: a. a known line feature and a position, b. or measure, along the feature. 3. The method provides the ability to uniquely identify positions along lines without explicit x,y coordinates.Institute of Geology, University of the PunjabTuesday, January 28, 2014 5. 5Modeling Of Data In Arc GIS 1. In Arc GIS, geographic data is stored in three ways: a. As a collection of features in a Vector format. b. As an array of cells in Raster format. c. As a set of triangulated points in TIN. Talking about the Vector Data Format Only !Institute of Geology, University of the PunjabTuesday, January 28, 2014 6. 6Why Use Linear Referencing? 1. As we know that In the vector format, each feature has a geometry associated with it. Each geometry is composed of two dimensional (x,y) or three dimensional (x,y,z) coordinates. 2. Many organizations collect data about the linear features as a point location along the line as an alternative to expressing the location using xy-coordinates. 3. While the vector data is useful for the representation of the Static Data, like, water bodies, parcel boundaries etc. 4. Also used to associate the multiple-attributes to a set of linear features, without splitting. Institute of Geology, University of the PunjabTuesday, January 28, 2014 7. 7mile 5 30o4025N, 96o2232W E.g., The concrete road surface starts at mile NOT The concrete road surface starts at 30o4025N, 96o2232W. Institute of Geology, University of the Punjab5,Tuesday, January 28, 2014 8. 8Accident occurred 50 meters along Main St.Main St 152040608095 Features using a linear system of measure. Features location determined using a linear system of measure values, instead of using x,y coordinates.Institute of Geology, University of the PunjabTuesday, January 28, 2014 9. 9 Features containing frequently segmented data. Some types of features have attributes that change frequently.Institute of Geology, University of the PunjabTuesday, January 28, 2014 10. 10Implementation In Arc GIS 1.Primary Data Types:a. Route Feature Classes b. Event Tables 2. Process: Dynamic Segmentationa. Line feature from a route feature class b. Events from event table are located in line featureInstitute of Geology, University of the PunjabTuesday, January 28, 2014 11. 11Route 2. A Route is a path through a network. 3. Routes are stored in a feature class whose geometry type is Polyline. 4. By definition: A polyline is an ordered collection of paths. 5. Polylines with measures are stored as polyline-M type. 6. Measure values are ONLY stored in Vertex (for Polyline also). Between them, the data is interpolated.Institute of Geology, University of the PunjabTuesday, January 28, 2014 12. 121.A route is a linear feature that has: a. A unique identifier and b. A measurement. Route 711081Linear feature Institute of Geology, University of the PunjabUnique identifier Tuesday, January 28, 2014 13. 13Measurements of Route 1. Measures are the Distance along a Route from an Origin 2. The measures are independent of the underlying feature geometry. a. If the data is in UTM, then its measure values can be in feet or inches etc 3. They can, along a route, increase, decrease, or remain the same. 4. The measures are stored as long binary data (i.e. x,y,m) OR (i.e. x,y,z, and m) 5. By definition, the measures are common to all routes in the feature class.Institute of Geology, University of the PunjabTuesday, January 28, 2014 14. 14Transportation Accidents 45Speed Railroad035204540605580100 Features containing one-to-many relationships Two or more pieces of information associated with the same location on a lineInstitute of Geology, University of the PunjabTuesday, January 28, 2014 15. 15Event Tables 1. Events are geographic location stored in Tabular rather than Spatial form. 2. Event types include address events, route events, xy events, and temporal events. 3. Specifically, route events can be linear, continuous, or point features occurring along a base route system. 4. Route locations thematically stored in tables are called Route Events or simply Events. 5. Two types: Point Event Table E.g., Accidents, Sample sites Line Event Table E.g., Pavement conditions, Riverbank composition Institute of Geology, University of the PunjabTuesday, January 28, 2014 16. 16I10Accident occurred at mile 23Kenai RiverSalmon found between mile 10 and mile 20Institute of Geology, University of the PunjabTuesday, January 28, 2014 17. 17Point Event Tables 1.A feature that occurs at a precise point location along a route and uses a single measure value. 60 53 2. Two required fields: 45 Route ID identifies route on which event is located Measure is the events location on the route 34 Route location Attributes 3. Other attributes about the event. Route 114 40 Institute of Geology, University of the PunjabTuesday, January 28, 2014 18. 18Institute of Geology, University of the PunjabTuesday, January 28, 2014 19. 19Line Event Tables 1. Linear events are used to model portions of routes and are stored in tables. 2. Three required fields Route ID identifies route on which event is located From Measure and To Measure define beginning and end of line event 3. Other attributes about the event Route location60 Route 48Attributes250 Institute of Geology, University of the PunjabTuesday, January 28, 20140 20. 20Institute of Geology, University of the PunjabTuesday, January 28, 2014 21. 211. A Point event describes a discrete location along a route (a point), whereas 2. A Line event describes a portion of a route (a line). 3. All of the data is important, but to segment the linear data (geometry) to create a Break or Segment every time a change occurs is not an efficient way to store or manage the dataset. This Lead us to the Concept of Dynamic SegmentationInstitute of Geology, University of the PunjabTuesday, January 28, 2014 22. 22Dynamic Segmentation 1.There are Two requirements for dynamic segmentation: a. A table of events that include a unique identifier and associated measures, b. And a collection of linear features that include a unique identifier and a measurement system. 2. Dynamic segmentation is the process of computing map location of events. Events are stored and managed in an event table. The linear referencing measurement system is used to display events on a map.Institute of Geology, University of the PunjabTuesday, January 28, 2014 23. 23Institute of Geology, University of the PunjabTuesday, January 28, 2014 24. 24Benefits of Dynamic Segmentation 1. Multiple sets of attributes can be associated with any portion of an existing linear feature. 2. More importantly, attributes may be displayed, queried, edited and analyzed without affecting the underlying linear feature geometry 3. The use of linear referencing permits you to dynamically locate a segment, without the need to edit feature data geometry resulting in more efficient data management.Institute of Geology, University of the PunjabTuesday, January 28, 2014 25. 25Working with Arc GIS 9.3 1. Following are the sub-set tools in Arc GIS 9.3 Toolbox for Linear Referencing Tools: a. Calibrate Routes b. Create Routes c. Dissolve Route Events d. Locate Features along the Routes e. Make Route Event Layer f. Overlay Route Events g. Transform Route Events Institute of Geology, University of the PunjabTuesday, January 28, 2014 26. Institute of Geology, University of the PunjabTuesday, January 28, 2014Data for Practice1. Utah (USA) Road And Highway System 2. In Geo-database Fomrat 3. Coordinate System: NAD 198326 27. 27Create Routes* So to have the options of Route PropertiesInstitute of Geology, University of the PunjabTuesday, January 28, 2014 28. 28Institute of Geology, University of the PunjabTuesday, January 28, 2014 29. 29Calibrate Routes* For just to have an updateInstitute of Geology, University of the PunjabTuesday, January 28, 2014 30. 30Institute of Geology, University of the PunjabTuesday, January 28, 2014 31. 31Institute of Geology, University of the PunjabTuesday, January 28, 2014 32. 32Institute of Geology, University of the PunjabTuesday, January 28, 2014 33. Dissolve Route Events33* For division of event tableInstitute of Geology, University of the PunjabTuesday, January 28, 2014 34. 34Institute of Geology, University of the PunjabTuesday, January 28, 2014 35. Locate Feature Along Route35* Pick those points that intersects the linear featureInstitute of Geology, University of the PunjabTuesday, January 28, 2014 36. 36OutputInput PointsInput LinesInstitute of Geology, University of the PunjabTuesday, January 28, 2014 37. Make Route Event LayerInstitute of Geology, University of the Punjab37Tuesday, January 28, 2014 38. 38Institute of Geology, University of the PunjabTuesday, January 28, 2014 39. Overlay Events39* Overlays two event table on the basis of their unique IDInstitute of Geology, University of the PunjabTuesday, January 28, 2014 40. 40Input_1Input_2Overlay OutputInstitute of Geology, University of the PunjabTuesday, January 28, 2014 41. Transform Route EventsInstitute of Geology, University of the Punjab41Tuesday, January 28, 2014 42. 42Sample_ExampleInstitute of Geology, University of the PunjabTuesday, January 28, 2014 43. 43Summary ToolInput_1Input_2Input_3OutputCreate Route.shp / .dbf--Route .shp /.dbfCalibrate RouteRoute .shp /.dbfPoint/line .shp /.dbfDissolve Route EventsTableUnique IDDissolve FieldEvent TableMake Route Event LayerRoute .shp /.dbfEvent Table-Table & .lyrLocate Feature Along the Route.shp / .dbfRoute .shp /.dbfEvent Table OR .dbfOverlay Route EventEvent TableEvent TableEvent TableTransform Route EventsEvent Table.shp / .dbfInstitute of Geology, University of the Punjab.shp /.dbf.sh / .dbfEvent tableTuesday, January 28, 2014 44. Tuesday, January 28, 2014Institute of Geology, University of the PunjabReferences 1. 2. 3. 4. 5.Linear Referencing in Arc GIS Tutorial PDF Linear Referencing by: Christopher Grasteit, Technical Marketing Working with Linear Referencing and Routes, by: www.junipergis.comlinks www.help.arcgis.com www.rnr/geog420/520 (Spring 2008)44 45. Institute of Geology, University of the PunjabTuesday, January 28, 201445