Subtitle is linear referencing which is the major type of Geo referencing.

1. Physical Geography
Linear Referencing
Linear referencing is
the method of storing geographic locations by using
relative positions along a measured linear feature.

2. By:
Muhammad Azeem Mazhar

3.  Example:
Measurements along features are used to locate point
events and line events using a number of conventions.
A point can be located along the line in the graph below:
• At measure 12 along the line.
• 4 units east of measure marker 10
along the line .
•The line starts at measurement 18
and ends at 26.
•The line starts at measurement 28
and continues for 12 units.

4. Why use linear referencing?
Linear referencing is used for many reasons. The following is the
two primary reason:
•Many locations are recorded as events along linear features—
for example, locations of traffic accidents are recorded using a
convention such as "27 meters east of reference mile marker 35
along State Highway 287."
•Linear referencing is also used to associate multiple sets of
attributes to portions of linear features without requiring that
underlying lines be segmented (split) each time that attribute
values change. For example, most road centerline feature classes
are segmented where three or more road segments intersect and
where the road names change.

5. Dynamic segmentation is the
process of computing the map locations of events stored
and managed in an event table using a linear referencing
measurement system and displaying them on a map. The
term dynamic segmentation is derived from the concept
that line features need not be split (in other words,
"segmented") each time an attribute value changes; you
can "dynamically" locate the segment.

6. Linear referencing sample applications:

7. •Highways and streets:
Agencies that manage highways and streets use linear
referencing in a variety of ways in their day-to-day
operations.
(i) Assessing pavement conditions.
(ii) Maintaining, managing, and valuing assets—for
example, traffic signs and signals, guard rails, toll booths,
and loop detectors.
(iii) Organizing bridge management information.
(iv)Reviewing and coordinating construction projects.

8. Highways and streets

9. Transit:
•Automatic vehicle location and tracking.
•Bus stop and facility inventory.
•Rail system facility management.
•Track, power, communications, and signal maintenance.
•Accident reporting and analysis.
•Demographic analysis and route restructuring.
•Ridership analysis and reporting.
•Transportation planning and modeling.

10. Railways use linear referencing to manage key information
for rail operations, maintenance, asset management, and
decision support systems. Linear referencing makes it
possible.

11. The petroleum industry manages tremendous volumes of
data used in geophysical exploration. Seismic surveys, or
shot point data, are used to help understand the
underlying geology in an area. The nature of seismic data
is that it must be represented as both a linear object—the
seismic line—and a collection of point objects (the shot
points).

12. (i) Collecting and storing information regarding pipeline
facilities.
(ii) Inline and physical inspection histories.
(iii) Regulatory compliance information.
(iv) Risk assessment studies.
(v) Geographic information, such as environmentally
sensitive areas, political boundaries , right-of-way
boundaries, and various types of crossings.

14. In hydrology applications, linear referencing is often
called river addressing. River addressing allows objects
such as field monitoring stations—which collect
information about water quality analysis, toxic release
inventories, drinking water supplies, flow, and so on—to
be located along a river or stream system. Furthermore,
the measurement scheme used in river addressing allows
the measurement of flow distance between any two points
on a flow path