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--- dev:technology:3d_mapping:linear_referencing [2018/10/10 08:13]
natalia.zheltukhina@orbitgt.com
+++ dev:technology:3d_mapping:linear_referencing [2024/01/12 08:21]
jeroen removed
@@ Line 1: / Line 1: @@
 ====== Linear Referencing ======
-{{:dev:technology:3d_mapping:linear_referencing_1900.jpg|}}
+{{  :dev:technology:3d_mapping:linearreferencing_1900.jpg?nolink  |}}
 ===== Concepts =====
-Linear Referencing (Linear Referencing System or LRS) is a technique of spatial referencing which defines localization of an object in relation to a linear feature, position is measured along a line of interest ([[https://en.wikipedia.org/wiki/Linear_referencing|Linear Reference WIKI]]).
+Linear Reference Measure Option enables the option to select a vector line dataset Measure Attribute Formula for every measurement, identifying linear distance from the beginning of the closest reference line to the dropped position of the center of the measurement onto this line.
-Linear Reference Measure Option enables additional Measure Attribute Formula for every measurement, identifying linear distance from the beginning of the closest reference line to the dropped position of the center of the measurement onto this line.
+===== LRS Input Data =====
-===== Measure with Linear Reference =====
+The LRS input must be a line vector dataset (.ovf, .ovt, .shp, ...) and added into the Orbit installation directory, ''program/system/linear_reference'', prior to starting the application.
-==== 3D Hover Preferences ====
+===== LRS for Measurements =====
-Activate 'Enable Linear Referencing' preference in the "Measure Options" group.
-==== Measure Sidebar ====
+=== Input Data ===
-If Linear Referencing is enabled, select 'Linear Referencing dataset' drop-down menu will appear on the Measure Sidebar, where all vector datasets of correct type available in the dataset list will be shown.
-==== Linear Referencing dataset Input ====
+Each line in the dataset is a linear reference segment.\\ To apply an offset distance from the beginning of the identified reference object, the Object attribute ''offset'' is used.
-Linear Referencing dataset can either of spatial type Line or Point. Point dataset should have attribute GPStime (in this case line segments will be defined by 2 consecutive in time points).\\
+=== Activate ===
-==== Result ====
+  - Add the Input Data, see above.
-The center of the measurement will be dropped perpendicular to the closest line segment of the reference dataset. If the reference dataset is 2D, closest perpendicular distance will be calculated in 2D. If the reference dataset is 3D, 3D distances will be used.
+  - Activate 'Enable linear reference measurements' in the 'Measure Options' of the '3D Hover' Preferences, see [[dev:desktop:preferences:3dhover|]].
+  - Select linear reference dataset from the drop-down combo box added on top of the Measure Sidebar.
+=== Measure ===
+The center of the measurement will be dropped perpendicular to the closest line segment of the LRS dataset. If the LRS dataset is 2D, the closest 2D perpendicular distance is calculated. If the LRS dataset is 3D, 3D distances are calculated.
+    * The dropped distance is shown as a pink line.
+    * The Linear Referencing segment is shown as a green line.
+    * Linear Referencing measurement results (LRef) are listed in the Measure Sidebar.
+===== LRS for Search and Geocode =====
+=== Input Data ===
+To search for the specific reference object, the Object attribute ''ID'', and if not available, the attribute ''Name'' is used.
+=== Activate ===
+  - Add the Input Data, see above.
+  - Select the linear reference dataset from the drop-down menu in the Main Toolbar Search component.
+  - Enter the 'ID' or 'Name' attribute value and a distance (meters) as an offset.
+=== Search ===
+===== LRS with Clip Box =====
+With Clip Box positioning slider and 'jumping distance' the clipping box can be easily moved along the linear referencing line if the Clip Box is defined (how to define clipping box, see [[dev:desktop:tools:clip|]]).
-- Display and Results
-Display the dropped distance as dashed line
-Display the linear referencing candidates as green line
-Add "Linear reference" to the measure results.