Governors Office for Technology

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Geographic Information Systemsfor Land Surveyors
- An Overview

• Sponsored by
• Governors Office for Technology
• Office of Geographic Information
• February 14, 2002
• Ross Mackay, Kentucky Geodetic Advisor, National
  Geodetic Survey
• Ted Stumbur, Geo-Processing Specialist III,
  Kentucky State Police

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Schedule

• 115 - 135 Welcome and introductions
• 135 - 315 Early afternoon session
• GIS Definition and Concepts
• Software Functionality
• GIS uses in Kentucky and elsewhere
• 315 - 335 Break (20 minutes)
• 335 - 515 Late afternoon session
• Opportunities for Providing Services
• Positional Accuracy and GIS
• Metadata and Data Acquisition

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What is GIS? - Definition

• GIS is an information system
• GIS as a software package uses database concepts
  along with map based interface for display
• GIS as a system consists of hardware, software,
  people, and data
• GIS as a tool supports business processes, or
  problem solving

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What is GIS? - Basic concept

• Point, lines, polygons, pixels
• Attribute tables
• Layers

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GIS Data Model

• VECTOR DATA
• Data is stored as points, lines and polygons
• Analysis is based on associated attribute data
  query or vector overlays.

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Points, lines and polygons represent features
features such as state boundaries
Attribute table contains information about each
feature
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GIS Data Model

• RASTER DATA
• Data are stored as pixels
• Data Analysis is based on manipulating pixel
  values

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Digital Elevation Model
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Data organized as layers

• Link basemap with
• resident agency data
• scanned documents, images or videos
• Global positioning system data
• Backdrop with
• digital aerial imagery or
• satellite imagery

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GIS and CAD

• GIS works best for data management and analysis
  (as a database system)
• CAD works best for graphic data creation and
  editing (as electronic paper)

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The Power of GIS

• DATA INTEGRATION
• GIS allows to query and analyze different types
  of data from different sources in an integrated
  manner
• DATA ANALYSIS
• GIS has analytical capabilities which go beyond
  feature mapping and attribute queries
• DATA VISUALIZATION
• GIS allows to visualize query or analysis results
  for better understanding and communication.

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Data Integration and Analysis

• Location
• Where is it?
• Condition
• What is it?
• Patterns
• How is it distributed?
• Trends
• What has changed?
• Modeling
• What if ?
• Time and Travel?
• What is near me?

• Data Integration from different sources
• Search and query
• Overlays (vegetation cover and slope)
• Spatial analysis (including statistics)

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Data Visualization

• Data and analysis results can be viewed in new
  and different ways
• Visualization reveals hidden relationships
• Provides better communication

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GIS DEMO

• ArcView 3.2 software
• Display point, line, polygon themes
• Display Attributes
• Query Attributes
• Spatial Query
• Display Raster Data

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Who uses GIS in KY?

• Local Governments
• State Governments
• Universities
• Utility companies
• Water districts
• etc

The application of GIS is limited only by the
imagination of those who use it. Jack
Dangermond President, ESRI
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Where do you find GIS in KY

• Consortiums or partnerships built around GIS
• Presence of City, County or Joint Planning
  Commissions
• Presence of countywide zoning
• Use of GIS by County PVA Office and existence of
  digital parcel data

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Kentucky Statewide Digital Basemap Initiative
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Basemap Data Sources

• DOQQ
• Digital Ortho Quarter Quad
• DRG
• Digital Raster Graphics
• DEM
• Digital Elevation Model

http\\ogi.state.ky.us
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GIS is used in daily work...
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Property Valuationand Land Records Management

• Parcel map updates

• Public access

• Tax assessment

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Flood Insurance Determinations
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Urban Development / Revitalization
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Statewide GIS Issues

• Data Sharing Arrangements
• Standardization
• content and terminology
• digital submissions
• other automation standards
• Metadata (cataloguing data)
• Spatial Data Quality Assurance
• Geodetic Reference
• National Spatial Reference System Federal Base
  Network
• Single Zone State Plane Coordinate System
• Height Modernization

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National Spatial Reference System(NSRS)

• Consistent National Coordinate System
• Latitude
• Longitude
• Height
• Scale
• Gravity
• Orientation
• and how these values change with time.

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Federal Base Network

• A nationwide, 100 kilometer array of geodetic
  control stations positioned to 2-centimeter
  accuracy of latitude, longitude, and height.
• The FBN will resolve positional discrepancies
  between existing state HARN and the National CORS
  network, improve the quality and homogeneity
  NSRS, provide the observations necessary for a
  comprehensive nationwide datum readjustment, and
  improve geoid modeling.
• 35 States completed or being worked on.
  Kentucky is next.

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• Kentuckys FBN
• Coordinated by NGS through Kentucky
  Transportation Cabinet.
• NGS is assisting in project planning, and will
  provide observer training and on-site project
  supervision
• NGS will process the data and incorporate the
  survey results into the NSRS.
• KYTC is extending HARN control by establishing
  at least one monument in each county.
• KYTC will provide personnel and equipment for
  collection of data at these sites.

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• Kentuckys FBN
• All Kentucky surveyors are invited to
  contribute by attending training and co-observing
  at approved locations.
• For each station, perform at least three
  5½-hour GPS observations on separate days and
  include at least one start time shift of 4 hours
  or more.
• Observation Campaign tentatively
  scheduled for Winter 2002.

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Kentucky Single ZoneState Plane Coordinate System
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Rationale for a Single Zone

• Advances in GIS, hardware, and network technology
  have made it feasible to create, manage, access,
  view, query, and analyze high resolution datasets
  covering large geographic areas.
• Analyzing raster data over a large geographic
  regions such as watershed or highway corridor
  within the state is practical only when all data
  is presented in the same coordinate system or
  reference frame.
• A uniform coordinate system will facilitate
  non-vector data integration and viewing on
  statewide basis, and eliminate extra cost and
  effort needed to maintain the current overlap
  areas between the North and South Zones.
• A survey grade projection will allow surveyors
  and engineers to develop plans capable of being
  constructed on the ground in a single zone with
  minimal grid to ground distortions, thus
  facilitating the development of highly accurate
  mapping data for GIS.

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KY1Z

• NGS now provides Single Zone coordinates on
  Data Sheets designated as KY1Z
• North and South Zones are still published.
• Data Sheets also now provide coordinates in
  both U.S. Survey Feet and Meters.

• Designed primarily for statewide GIS concerns,
  the ground to grid distortion has been balanced
  to fit the needs of most surveying applications.

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Height Modernization

• The goal of Height Modernization is to provide a
  reliable and accurate infrastructure for
  elevation data enabling the development of a more
  accurate geoid model and a more precise statewide
  DEM.

• The resulting improved geoid model provides the
  ability to derive accurate elevations using GPS
  observations. An accurate DEM provides the
  ability to create shaded relief maps, slope
  models, watershed models, volumetric modeling,
  vertical profiling and sections.

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Height Modernization in Kentucky?

• Full implementation of height modernization
  nationwide, is an enormous undertaking that will
  take many years, and will require partnering with
  the private sector, state and Federal agencies.

• State Criteria for Participation in Height
  Modernization
• State Organization with statewide credibility
• Commitment to work with NOAA to ensure
  consistency with National Height Modernization
  objectives
• Reliance on NOAA's Height Modernization
  guidelines
• State height needs determined using public
  forums
• Use of contracts with the private sector

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Geographic Information Systemsfor Land Surveyors
- An Overview
Break
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GIS and Surveyors

• GIS is part of and supports daily business in
  many organizations
• Surveyors create geographic information
• GIS is dependent on reliable geographic
  information
• Surveyors bring integrity and reliability to
  geographic Information

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Opportunities for expanded range of services

• Clients may request the surveys to be submitted
  in GIS format
• Surveyors may provide their expertise for
  improving GIS
• Data accuracy assessment services
• Data conversion and analysis services
• Sub-contracting for GIS consultants

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Digital Submissions

• More state and local government agencies require
  the submission of map information in digital
  format
• Most often in GIS format
• CAD is usually acceptable

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Defining Accuracy

• There are many types of accuracy associated with
  GIS
• Accuracy in this presentation is referred to as
  POSITIONAL accuracy
• Positional accuracy is the difference between the
  mapped feature and its true position on the
  ground.
• Other Types of Accuracy
• Attribute accuracy
• Temporal accuracy

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Survey Document or GIS Data

• GIS - Get It Surveyed?
• Data is not more accurate just because it is in a
  computer
• BUT, it can be as accurate as you want it to be

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Why would you need survey accuracy for your GIS
data

• Maps use scale
• Survey is 11 measurements (iron in the ground)
• GIS Data is stored as coordinates
• Software does not know nor discriminate between
  different accuracies

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GIS Accuracy requirements

• The entire GIS is only as accurate as the least
  accurate layer
• Surveyors are equipped to evaluate accuracy
  requirements
• Accuracy requirements are usually determined by
  balancing the budget against intended uses

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Accuracy vs. cost
cost
accuracy
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Accuracy vs. usefulness
usefulness
accuracy
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Absolute vs. relative location

• Absolute location refers to a position on the
  surface of the Earth expressed in some Cartesian
  coordinate values or angular measurement
  (latitude, longitude). Absolute accuracy is
  quantifiable.
• A relative location refers to a position of
  certain features in relationship to others. Many
  GIS databases opt for relative rather than
  absolute location accuracy.

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Metadata is necessary for accountability

• Metadata is a description of data
• intended uses
• coordinate system
• accuracy
• development methods
• Helps to identify and find data
• Covers your butt...

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Data acquisition

• Enter field survey notes - COGO
• GIS accepts a variety of electronic file formats
• Survey data collectors with built in GIS
  capabilities being developed

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New Integrated GPS/GIS Tools
Agriculture Asset Management Construction Environm
ental Forestry Factory Automation Mapping
GIS Marine Military Mining OEM Boards and Chip
Sets Public Safety Survey Timing
Synchronization Transportation Vehicle
Security Urban Municipal Utilities
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NGS Monuments on the Webhttp\\ngs.state.ky.us
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NGS Monuments on the Web
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NGS Monuments on the Web
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NGS Monuments on the Web
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NGS Monuments on the Web
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Questions?Thank You.

• Ross Mackay, Kentucky Geodetic Advisor
• National Geodetic Survey
• Ross.Mackay_at_mail.state.ky.us
• 21 Millcreek Park
• Frankfort, KY 40601
• Phone [phone]
• Fax [phone]
• Ted Stumbur, Geo-Processing Specialist III
• Kentucky State Police
• Ted.Stumbur_at_mail.state.ky.us