Course Information

1. 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

2. 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.

3. 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

4. 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. Traditionally, 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.state.mn.us/images/Geodetic%20Control.gif next Topic Geodetic Control Data in Action

5. 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 next Topic Geodetic Control in action

6. 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 next Topic Geodetic Control Exercise

7. 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 let’s 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 next Topic Module Summary

8. 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

9. Module 2: Geodetic Control of the Framework Data Content Standard Key Terms Topics Geodetic Control Framework Standard Framework Control 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

10. Next Topic Purpose for the Standard 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.

11. Next Topic Goals of the Standard 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).

12. Next Topic Capacities of the Standard 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

13. 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

14. 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: (703) 648-5514 Facsimile: (703) 648-5755 Internet (electronic mail): fgdc@fgdc.gov WWW Home Page: http://www.fgdc.gov next Topic Module 2 Exercise

15. Geodetic Control Module exercise Now that you have some basic Geodetic Control knowledge let’s 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 next Topic Module Summary

16. 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

17. 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

18. 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 annex’s are included with the standard documentation. next Topic Geodetic Control Requirements Continued

19. 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 next Topic Geodetic Control Requirements Continued

20. 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. next Topic Geodetic Control Requirements Continued

21. 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

22. 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

23. 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

24. Module 4: Examples, Exercise, and Certificate Topics • Geodetic Control Example • Review Exercise • Certificate of Completion next Topic Review Exercise

25. 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/geoid/geoid-ellipsoidal-orthometric_height.jpg next Topic Exercise

26. 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/datasheethttp://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. next Topic Course completion

27. 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/readstep2.html. After you open the certificate file, type your name and today’s date on the name/date line and print. Click here to receive course certificate