The National Spatial Data Infrastructure (NSDI) Framework is a collaborative initiative to develop a set of commonly used geographic datasets that are compatible based upon spatial location and content. The Framework approach allows data collected for

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Framework Data Content - Geodetic Control
Related Topics
NSDI Training Tracks An initiative to define
areas, topics, and materials for
training within the NSDI. ISO 19100 Series
Suite of standards developed for geographic
data and datasets. The most notable is ISO
19135 which pertains to metadata. ANSI
Standards Similar work to ISO, but
standards directly apply to data created
within the United States.
Course Information
The National Spatial Data Infrastructure (NSDI)
Framework is a collaborative initiative to
develop a set of commonly used geographic
datasets that are compatible based upon spatial
location and content. The Framework approach
allows data collected for variety of reasons and
agencies to work together seamlessly which can
ultimately reduce project costs and increase
interagency cooperation. The Framework Data
Content Base Standards Suite dictates the
requirements for Framework data. This course
covers the fundamentals of the Framework Data
Theme Geodetic Control as developed by the
Framework Data Content Standard. It is designed
for users who are both interested in an overview
of the Framework Data Content Standard Geodetic
Control theme as well as designers and developers
implementing Framework data, and associated tools
specific to Geodetic Control data.
Prerequisites

• General Understanding of geodetic referencing
  and horizontal and vertical datum's
• General Understanding of GIS, Geospatial Data
  and Metadata
• Familiarity with the Federal Geographic Data
  Committee (FGDC)
• Familiarity with the National Spatial Data
  Infrastructure (NSDI)
• Basic knowledge of Geographic Data Standards
  (specifically ISO 19100 series)
• Completion of Framework Data Content Base
  Standard Course

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Navigating Through the Course
Explanation of Navigation Buttons
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Learning Objectives
Understand Geodetic Control Data Comprehend
basics of Geodetic Control framework
standard Understand how to implement the
standard
Course modules

• Understanding Geodetic Control
• Geodetic Control (Part 4) of the Framework Data
  Content Standard
• Implementing the Geodetic Control Standard
• Course Review

Estimated Time
Estimated time for the entire course is 100
minutes.
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Module 1 Understanding Geodetic Control
Time Requirement
Topics

• What are Geodetic Control Data
• Types of Geodetic Control Data
• Geodetic Control in Action
• Module Exercise and Summary

Estimated time for this module is 30 minutes
First Topic
What are Geodetic Control Data
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What is Geodetic Control Data
Geodetic control is normally established by,
either measurements of angles and distances or
the Global Positioning System (GPS). GPS uses
electronically measured ranges between ground
receivers and a constellation of satellites
operated by the US Department of Defense. No
matter which measuring system is employed,
geodetic control is established in a hierarchical
manner. More densely spaced points are
established by starting from a most precise, but
rather sparse, network of points. This method is
generally less precise but sufficient to
meet most specific user needs. The various
requirements for geodetic control demand
different levels of positional accuracy. Tradition
ally, geodetic control is categorized as primary,
secondary, or supplemental. Primary or First
Order control is used to establish geodetic
points and to determine the size, shape,
and movements of the earth. Secondary or Second
Order, Class I control is used for
network densification in urban areas and for
precise engineering projects. Supplemental or
Second Order, Class II and Third Order control is
used for network densification in non-urban areas
and for surveying and mapping projects In order
to ensure the accuracy of land record systems as
well as natural resource, communication,
transportation, and other mapping projects, it is
essential to have a consistent coordinate system.
The National Spatial Reference System (NSRS),
under the management of the National Geodetic
Survey (NGS) and managed by the Federal Geodetic
Control Subcommittee (FGCS), is the standard in
defining the latitude, longitude, elevation,
scale, gravity, and orientation of control points
throughout the United States. Both state and
local governments have producers that generate
geodetic control data for smaller-scale
needs Today, the technological expansion of GPS
has made it possible to perform extremely
accurate geodetic surveys at a fraction of the
former cost. While this is a brief overview of
Geodetic Control, the topic and details are
beyond the scope of these materials. Feel free
to explore the following website for more
information http//www.ngs.noaa.gov
A n example of a benchmark marker http//www.gis.s
tate.mn.us/images/Geodetic20Control.gif
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Geodetic Control Data in Action
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Geodetic Control Data
Geodetic control surveys are usually performed to
establish the basic positional framework from
which supplemental surveying and mapping are
performed. Geodetic control surveys are
distinguished by use of redundant,
interconnected, permanently monumented control
points that comprise the National Spatial
Reference System (NSRS) or are often incorporated
into NSRS. Geodetic control surveys are
performed to far more rigorous accuracy and
quality assurance standards than those for local
control surveys for general engineering,
construction, or topographic mapping purposes.
Geodetic control surveys included in NSRS meet
automated data recording, submittal, project
review, and least squares adjustment requirements
established by the Federal Geodetic Control
Subcommittee (FGCS).
A screen capture of the CRSC Data Portal, showing
different Control points across the SW
USA. http//csrc.ucsd.edu/maps/mapBrowser.html
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Geodetic Control in action
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Geodetic Control in action
In the example to the right we see geodetic
control data for the state of Kentucky. We can
get a clear idea of the set of control points
(geodetic control) that establish a link between
real world locations and their correct
corresponding locations via maps and mapping
applications.
http//kygeonet.ky.gov/ngs/viewer.htm
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Geodetic Control Exercise
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Geodetic Control s Module 1 exercise
Geodetic Control data is being applied and used
in real world projects by many Federal, State,
and local agencies. These agencies use Geodetic
Control data for a variety of reasons. Now that
you have some basic Geodetic Control knowledge
lets see some a Geodetic Control data set in
action. Step 1) Open an Internet Browser and
proceed to http//csrc.ucsd.edu/ Step 2)
Explore the California Spatial Data Reference
Center Map Browser Step 3) Click on several one
of the data points on the map Step 4) Notice the
general information that is displayed, explore
the other information you can acquire Step 5)
Close all Internet windows and proceed with
the course
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Module Summary
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Module Summary
Understanding Geodetic Control

• Geodetic Control data describe how people
  delineate a landscape
• Many different Geodetic Control features can be
  collected, mapped, and utilized for a variety of
  reasons
• Different control points can serve different
  purposes.

next Topic
Module 2 Geodetic Control (Part 4) of the
Framework Data Content Standard
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Module 2 Geodetic Control of the Framework Data
Content Standard
Key Terms
Topics
Geodetic Control Framework Standard Framework Cont
rol Points Survey

• What is the Geodetic Control Standard
• Purpose for Standard
• Goals of the Standard
• Capacities of the Standard
• Standard Related Contact Information
• Module Exercise and Summary

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What is the Geodetic Control s standard
Quick Facts
Each Framework standard part was developed and
edited by thematic experts Geodetic Control is
one of the seven themes of Framework data. Each
has a separate standard, some including
subparts. All standards use the Framework Data
Content Base Standard as the foundation for this
data.

• The Geodetic Control Framework Data Content
  Standard
• One of the seven themes defined as Framework
  data
• Establishes a baseline for Geodetic Control
  data collection and distribution
• Builds on the Framework Data Content Base
  Standard and Framework Geodetic Control s
  Standard.
• Only when a dataset meets the requirements set
  forth in its thematic standard part and the
  Framework Base Standard can it be considered
  Framework data.

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Purpose for the Standard
More Information
This part of the Framework Data Content Standard
is applicable to any geodetic control dataset and
is intended to facilitate a common methodology to
create, manage, and share geodetic control
datasets from various organizations at the
Federal, State, Tribal, and local government
levels academia and the private sector.
Although this part does not encompass
non-geodetic control points, such as Public Land
Survey System points, local government control
points, project control points for public and
private projects, aerial-photo control points,
and so on, it can be used as a model for other
control points and coordinated points.
This standard provides a common methodology for
creating datasets of horizontal coordinate values
and vertical coordinate values for geodetic
control points represented by survey monuments,
such as brass disks and rod marks. It provides a
single data structure for relating coordinate
values obtained by one geodetic survey method
(for example, a classical line-of-sight traverse)
with coordinate values obtained by another
geodetic survey method (for example, a Global
Positioning System geodetic control survey).
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Goals for the Geodetic Control Standard

• The goal of the Geodetic Control part of the
  Framework Data Content Standard is to provide
  common definitions and syntax to enable
  collaborative development, use, and exchange of
  data specific to Geodetic Control data
• The audience for this part of the standard
  includes Geodetic Control data users,
  maintainers, and distributors. Specific guidance
  on the implementation of the data that meets
  framework specifications for Geodetic Control is
  outlined

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Capacities for the Geodetic Control Standard
More Information
This part of the Framework Data Content Standard
is applicable to any geodetic control dataset and
is intended to facilitate a common methodology to
create, manage, and share geodetic control
datasets from various organizations at the
Federal, State, Tribal, and local government
levels academia and the private sector.
Although this part does not encompass
non-geodetic control points, such as Public Land
Survey System points, local government control
points, project control points for public and
private projects, aerial-photo control points,
and so on, it can be used as a model for other
control points and coordinated points.

• The development of this part of the Framework
  Data Content Standard will greatly assist in
  mitigating the following issues
• Duplication of data and application development
• Complications exchanging Geodetic Control data
  and information
• Difficulties integrating data
• Poor framework/support for analytic activities
• Difficulties managing multiple representations
  of features

next Topic
Contact Info
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Who to Contact for Questions about the Geodetic
Control s Standard Part
Standard Coordination
The FGDC is the responsible organization for
coordinating work on all parts of the Geographic
Information Framework Data Content Standard. The
development and maintenance authority for Part 6
Geodetic Control is held jointly by the U.S.
Geological Survey and U.S. Environmental
Protection Agency. The FGDC shall be the sole
organization responsible for direct coordination
with the InterNational Committee for Information
Technology Standards (INCITS) concerning any
maintenance or any other requirements mandated by
INCITS or ANSI.
Federal Geographic Data Committee Secretariat c/o
U.S. Geological Survey 590 National
Center Reston, Virginia 20192 USA Telephone
[phone] Facsimile [phone] Internet
(electronic mail) fgdc_at_fgdc.gov WWW Home Page
http//www.fgdc.gov
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Module 2 Exercise
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Geodetic Control Module exercise
Now that you have some basic Geodetic Control
knowledge lets see some a Geodetic Control data
set in action. Step 1) Open an Internet
Browser and proceed to http//gis.nysdot.gov/
geodeticcontrol/ Step 2) Explore the New York
State Department of Transportation Geodetic
Control Viewer Step 3) Click on identify and
then on one of the data points on the map Step
4) Notice the information that is displayed. What
types of reference (geodetic) can your gather
from this data? Step 5) Close all Internet
windows and proceed with the course
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Module Summary
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Module summary

• The goal of the Geodetic Control s part of the
  Framework Data Content Standard is to provide
  common definitions and model to enable
  collaborative development, use, and exchange of
  Geodetic Control data.
• Establish the content requirements for the
  collection and interchange of Geodetic Control
  features
• The Geodetic Control part is one of the seven
  themes of Framework Data

next Topic
Module 3 Geodetic Control Requirements
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Module 3 Geodetic Control Standard Requirements
Time Requirement
Topics
Estimated time for this module is 60 minutes

• Framework Data Content Geodetic Control Standard
  Requirements
• Encoding and Implementing the Standard
• Module Summary

Key Terms
UML Coding Elements Feature Relationships
First Topic
Geodetic Control Standard Requirements
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Framework Data Standard Geodetic Control
Requirements
In this module you will learn about the three
different requirements for Framework Geodetic
Control data, as specified in the standard.
Each requirement is addressed as a separate
topic, however more attention may be given to
certain requirements as they are the most crucial
requirements for creating Framework quality
Geodetic Control data. Many of the requirements
are specific UML features. For these
requirements the a brief description of the
component will be included. Please see the UML
chart and associated tables, included as an
appendix in the standard for specifics.
Additionally encoding and implementation will
be covered briefly. Also note that data
dictionaries, and code lists and standard annexs
are included with the standard documentation.
next Topic
Geodetic Control Requirements Continued
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Framework Data Standard Geodetic Control
Requirements
The diagram to the right is the UML flow chart
for the Framework Geodetic Control Standard.
This diagram shows the components and
relationships that comprise the Framework
Geodetic Control Standard. UML is designed to
show these relationships in a generic manner
without specifying a coding language or specific
software needed to complete the task. For more
information about UML visit http//www.uml.org
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Geodetic Control Requirements Continued
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Framework Data Standard Geodetic Control
Requirements
The following is a list of the four main UML
components to the Geodetic Control Standard
including a brief description of the
requirement ControlPoint ControlPoint is a
class that contains the identifier for the point,
information about horizontal coordinates,
accuracy, and datum. ControlPoint also contains a
link to a resource for the point. It also
contains an association with the UML class
VerticalInformation. VerticalInformation
VerticalInformation is a class that contains
information about vertical coordinates associated
with ControlPoint, including the type of height,
accuracy, and datum. This class also contains an
association with ControlPoint. RS_Identifier
RS_Identifier is a class that contains
information about the namespace used for the
reference system, namely the datum. HeightType
code list HeightType is a non-exhaustive
CodeList of values for the attribute heightType.
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Geodetic Control Requirements Continued
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Framework Data Standard Geodetic Control
Requirements

• UML model
• The UML diagram was introduced earlier, however
  it is a major component in the Geodetic Control
  Standard, as such a larger version is provided to
  the right.
• Notice the relationships and instances allowed in
  the UML diagram

next Topic
Geodetic Control Requirements Continued
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Encoding and implementation
The Bigger Picture
The Framework Standards do not have a specific
application schema that can be implemented.
Implementation of the Framework Standards in
relation to data and tool creation occurs at the
thematic level. Each thematic part complies with
the Framework Base Standard. As such a layer
(for example) created in accordance with the
Framework Geodetic Control part meets all
Framework requirements.

• The process of encoding is simply formatting or
  structuring data in a regulated manner. The
  Framework standards are encoded by applying the
  application schemas through the use of several
  different modeling and markup languages
• Unified Modeling Language (UML)
• Extensible Markup Language (XML)
• Geographic Markup Language (GML)
• Specific knowledge of each language is important
  for data and tool designers for more information
  see the Framework Base Standard Training
  Materials.

next Topic
Module Review
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Module 3 Geodetic Control Requirements Summary

• Three different requirements, with multiple
  subparts are specified by the Framework
  Governmental Boundaries Standard
• This module covers the specifications for
  Geodetic Control framework data implementation
• Provides rigid requirements to ensure proper
  structure and documentation for Geodetic Control
  data
• UML diagrams and data dictionaries provide
  specifics for programmers and data creators to
  develop Geodetic Control data that meets
  Framework specifications

next Topic
Module 4 Summary
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Module 4 Examples, Exercise, and Certificate
Topics

• Geodetic Control Example
• Review Exercise
• Certificate of Completion

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Review Exercise
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Review of Geodetic Control
This example illustrates how geodetic control
works and the need for known points to tie the
real world to the way we define data as it
appears on a map or in mapping applications.
http//principles.ou.edu/earth_figure_gravity/geoi
d/geoid-ellipsoidal-orthometric_height.jpg
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Exercise
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Geodetic Control Exercise

• So far we have looked at two separate mapping
  applications that show geodetic control points,
  however there are many more
• Open an Internet Browser
• Pick your favorite search engine (Google, Yahoo,
  etc)
• Type in Geodetic Control Map
• Search 3 or 4 different sites and compare them
  and how they display Geodetic Control data
• Now visit http//www.granit.unh.edu/geodetic/data
  sheethttp//www.granit.unh.edu/geodetic/datasheet
• Compare how New Hampshire shares its Geodetic
  Data as compared to some of the other sites. Are
  there advantages and/or disadvantages?
• Close your web browser and continue on with the
  course.

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Course completion
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Course Certificate
Congratulations, you have successfully completed
the Framework Geodetic Control s Standard
Training! In order to print the certificate
below you will need a copy of Adobe Acrobat
Reader, http//www.adobe.com/products/acrobat/read
step2.html. After you open the certificate file,
type your name and todays date on the name/date
line and print.
Click here to receive course certificate