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 - Elevation
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 Elevation 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 Elevation theme
as well as designers and developers implementing
Framework data, and associated tools specific to
Elevation data.
Prerequisites

• 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
3
Learning Objectives
Understand Elevation Data Comprehend basics of
Elevation framework standard Understand how to
implement the standard
Course modules

• Understanding Elevation Data
• Elevation (Part 3) of the Framework Data Content
  Standard
• Implementing the Elevation Standard
• Course Review

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

• What is Elevation Data
• Types of Elevation Data
• Elevation in Action
• Module Exercise and Summary

Estimated time for this module is 30 minutes
First Topic
What is Elevation Data
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What Are Elevation Data
Hypsography, topography, elevation, TINS, and
contours. Digital elevation data are sets of
elevation measurements for locations distributed
over the land surface. Elevation data have many
practical uses ranging from environmental to
urban. Slope and aspect can be directly derived
from elevation. Stream delineation and
subsequently watershed boundaries can also be
derived. Elevation datasets are also used for
scenario analysis ranging from calculations of
cut and fill requirements by engineers for
projects relating to road construction to
viewshed analysis. Viewshed analysis (or
line-of-sight) uses topographical data to
determine the visibility of areas from a given
point. For example, a project in which a scenic
route is to be constructed may utilize elevation
to determine the visibility of the landscape from
various points to determine the best pathway to
construct. Elevation data can be generated from
existing contour maps, photogrammetric analysis
of stereo aerial photography, satellite imagery,
or laser-based (LiDAR). Elevation values are
most commonly shown relative to sea level. Thus
positive values indicate areas found above sea
level and negative values are places on the earth
found below sea level.
Color Shaded Relief of Continental
USA http//ned.usgs.gov/
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Elevation Data in Action
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Elevation Data
Spatial data are a visual representation or
interpretation of a real world feature. For
these materials we will focus on the spatial
elevation data. There are many types of
elevation data representations including
hypsography, topography, Triangular Irregular
Networks (TINS), and contours. Additionally, as
you can see below, there are many different ways
to represent these data. Thus there is a need
for some basic standards to allow people to share
the s data they created. As we progress through
these materials we will see the need and
importance of the Framework Data Content
Elevation standard.
DEM
Contour
TIN
http//hamish.bowman.googlepages.com/elevation.dem
.png/elevation.dem-full.jpg
https//engineering.purdue.edu/abe325/contour.gif
http//www.clintoncountyohgis.org/buttons/ LiDARHo
me/Clarksville20TIN.jpg
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Elevation in action
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Elevation in action
As we have already seen, elevation data comes in
a variety of formats. Additionally there are
different resolutions or scales that elevation
data can be derived from and viewed at. These
different scales have pros and cons. The higher
the resolution the more detailed the picture one
can see However there are drawbacks to higher
resolution including smaller study areas and
larger file sizes. Thus there is a need for both
common sense and planning in projects utilizing
elevation data, and standards that can supports
the different types and resolutions of elevation
data. Below is an two examples of elevation data
showing the difference between a 90M DEM and a
10M DEM for parts of Colorado.
90m DEM
10m DEM
http//www.innovativegis.com/basis/Su pplements/BM
_Dec_02/Ironing_Colorado_files/image001.png
http//blog.simgis.com/wp-content/uploads/2009/02
/shade_dem_less_one_mile.jpg
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Elevation Exercise
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Elevation s Module 1 exercise
Elevation data is being applied and used in real
world projects by many different agencies. These
agencies use elevation data for a variety of
reasons. Now that you have some basic elevation
knowledge lets see some elevation data sets in
action. Step 1) Open an Internet Browser and
proceed to http//seamless.usgs.gov/website/se
amless/viewer.htm Step 2) Explore the mapping
service Step 3) Turn on different layers and pan
around the map Step 4) Pay specific attention to
the elevation data and how it is displayed, and
how the tools provided can be used to view and
acquire the data Step 5) Close all Internet
windows and proceed with the course
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Module Summary
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Module Summary
Understanding Elevation

• Elevation data comes in multiple formats and can
  be used to show the topographic variation in a
  landscape.
• Many different elevation features can be
  collected, mapped, and utilized for a variety of
  reasons
• Different scales, data types, and resolutions
  serve different purposes.

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Module 2 Elevation of the Framework Data Content
Standard
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Module 2 the Framework Data Content Standard
Elevation
Time Requirement
Topics
Estimated time for this module is 30 minutes

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

Key Terms
Elevation Framework Standard Framework
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What is the Elevation s standard
Quick Facts
Each Framework standard part was developed and
edited by thematic experts Elevation 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 baseline for this data.

• The Elevation Framework Data Content Standard
• One of the seven themes defined by the FGDC as
  Framework data
• Establishes a baseline for Elevation data
  collection and distribution
• Builds on the Framework Data Content Base
  Standard and Framework Elevation 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
The primary purpose of this standard is to
describe geospatial elevation data models in the
support of the exchange of elevation information.
This document also seeks to establish a common
baseline for the semantic content of elevation
databases for public agencies and private
enterprises. It seeks to decrease the costs and
simplify the exchange of elevation data among
local, tribal, state, and federal users and
producers. That, in turn, discourages duplicative
data collection. Benefits of adopting the
standard also include the long-term improvement
of the geospatial elevation data through the
establishment of Web data services for elevation
data and maps within the community.
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Goals for the Elevation Standard

• This part of the Framework Data Content Standard
  identifies the geospatial data model elements
  required for digital elevation data to be used
  for the NSDI framework. The standard was written
  to include common geospatial elevation data
  models (point, grid, contour, triangulated
  irregular network, and profile) and to not
  restrict anyone wishing to contribute their
  elevation data to the NSDI. The standard supports
  both topographic elevation data (above a
  reference datum) and bathymetric elevation data
  (below a reference datum). Collecting and sharing
  NSDI digital elevation data that are consistent
  with this standard will assure the user community
  accurate and reliable access to the data.
  Furthermore, the principles described in this
  standard may be extended to other geographic
  entities to facilitate the exchange of other
  geospatial thematic data.
• The goal of the Elevation 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 Elevation data
• The audience for this part of the standard
  includes Elevation data users, maintainers,
  and distributors. Specific guidance on the
  implementation of the data that meets
  framework specifications for Elevation is outlined

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Capacities for the Elevation Standard
More Information
The FGDC is the responsible organization for
coordinating work on all parts of the Geographic
Information Framework Data Content Standard
including the Elevation Theme.

• 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 Elevation 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 Elevation
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
Elevation 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) gdc_at_fgdc.gov WWW Home Page
http//www.fgdc.gov
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Module 2 Exercise
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Elevation Module exercise

• Open up an Internet browser
• Explore NASAs Aster Satellite Map website
• http//asterweb.jpl.nasa.gov/gdem.asp
• Compare these different maps, how does this
  elevation data compare to other elevation data.
  Does the world scale give you more detail or
  information?
• Close web browser and continue on with the next
  part of the module

next Topic
Module Summary
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Module summary

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

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

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

Key Terms
UML Coding Elements Feature Relationships
First Topic
Elevation Standard Requirements
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Framework Data Standard Elevation Requirements
In this module you will learn about the three
different requirements for Framework Elevation
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
Elevation 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
actual standard for more specifics.
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Elevation Requirements Continued
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Framework Data Standard Elevation Requirements
The diagram to the right is the UML flow chart
for the Framework Elevation Standard. This
diagram shows the components and relationships
that comprise the Framework Elevation 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
Elevation Requirements Continued
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Framework Data Standard Elevation Requirements

• The following is a list of the four main
  components to the Elevation Standard including a
  brief description of the requirement
• Point
• A simple X, Y point file with an elevation field
  z
• TIN
• A triangulated irregular network (TIN) is a
  digital data structure used in a geographic
  information system (GIS) for the representation
  of a surface. A TIN is a vector based
  representation of the physical land surface or
  sea bottom, made up of irregularly distributed
  nodes and lines with three dimensional
  coordinates (x,y, and z) that are arranged in a
  network of non-overlapping triangles
• GRID
• A raster based elevation of a collection of cells
  each containing an elevation value
• Contour
• Lines showing breaks in topography with similar
  elevations
• Profile
• Cross sections or transects are lines that
  connect irregulary spaced points of varying
  elevations

next Topic
Elevation Requirements Continued
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Framework Data Standard Elevation Requirements

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

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Elevation Requirements Continued
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Framework Data Standard Elevation Requirements
3. Data Dictionary The data dictionary provides
all entity and attribute definitions, domains,
obligations/conditions, maximum occurrences and
data types for elements depicted in the UML
model. The data dictionary is to large too
provide in a user friendly format in these
materials, so a list of the elements is listed
below. A complete copy of the data dictionary is
provided as an appendix to these materials
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Encoding and Implementation
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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 Elevation 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.

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Module Review
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Module 3 Elevation Requirements Summary

• Elevation Data is available in many different
  formats Contours, TINs, GRIDs, Profiles, Points
  and all can be created at different scales and
  resolutions
• Can be used for many different types of analysis
• This module covers the specifications for
  Elevation framework data implementation
• Provides rigid requirements to ensure proper
  structure and documentation for Elevation data
• UML diagrams and data dictionaries provide
  specifics for programmers and data creators to
  develop Elevation data that meets Framework
  specifications

next Topic
Module 4 Standard Implementation
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Module 4 Examples, Exercise, and Certificate
Topics

• Implementation Example
• Review Exercise
• Certificate of Completion

next Topic
Review Exercise
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Implementation Example
http//www.lib.uwaterloo.ca/locations/umd/digital/
images/Collingwood3_D_000.jpg
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The example above, illustrates how elevation data
can be implemented and how that data can be used
to make a product for analysis and visualization,
in this case, a perspective view of a color
hillshade.
Exercise
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Elevation Exercise

1. Click on the following hyperlink
   http//www.ambercore.com/files/TerrapointWhitePape
   r.pdf
2. Review the paper and learn more about LiDAR and
   how it is changing elevation data collection
   today and in the future
3. See if you can answer the following questions as
   you review the document
4. What does LiDAR stand for?
5. How is LiDAR data collected?
6. What are the benefits?
7. What are the challenges?

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Course completion
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Course Certificate
Congratulations, you have successfully completed
the Framework Elevation 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.ht
ml. 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