Midterm next wednesday
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Midterm next Wednesday. Midterm. May start off with multiple choice Bulk will be short answer/short essay Lecture PPTs and your notes , readings in Longley et al., Zeiler Will not include Labs or Arc Marine exercise Journal articles. Major concepts. Representations Object vs Field

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Midterm next wednesday

Midterm next Wednesday



  • May start off with multiple choice

  • Bulk will be short answer/short essay

  • Lecture PPTs and your notes, readings in Longley et al., Zeiler

  • Will not include

    • Labs or Arc Marine exercise

    • Journal articles

Major concepts

Major concepts

  • Representations

  • Object vs Field

  • Model, data model, analysis model

  • Data models

    • UML terminology, basic procedure from

      • Reality --> conceptual --> logical --> physical

    • Customized Arc GIS data models

      • For enterprise GIS

  • Analysis Models

    • Binary, ranking, rating, weighted rating

Major concepts cont

Major concepts - cont.

  • Geodatabase

    • what it is, why it’s important

  • Topology, Spatial Analysis

    • what they are, why they are important, how they relate

  • Object orientation

    • Identity, inheritance, encapsulation

  • Data Sharing (barriers)

Concepts of data sharing longley et al chapter 11

Concepts of Data SharingLongley et al., Chapter 11

Nsdi geodata gov geospatial one stop gos

NSDI ---> geodata.govGeospatial One-Stop ( GOS )

  • Who needs to share data?

    • jurisdictions with common borders

    • jurisdictions in a region

    • private and public sectors

    • local, state, and Federal agencies

    • government and individuals

  • Geospatial One-Stop

    • www.geodata.gov/

Nsdi geodata gov geospatial one stop gos1

NSDI ---> geodata.govGeospatial One-Stop ( GOS )

  • State, local, private production of geospatial data

    • loss of Federal monopoly, patchwork

    • variable accuracy, level of detail

    • the WWW

    • everyone can be a producer, publisher, distributor ofgeospatial data

  • See GEO 465/565 lecture #6

    • dusk.geo.orst.edu/gis/lec06.html#nsdi

Barriers to data sharing

Barriers to Data Sharing

(1) interoperability

  • will ArcGIS read Intergraph data?

  • find a common format that both can read

    • output into the common format

    • input the common format

  • is the common format the same as one of the GIS formats?

    • if yes, only one conversion is needed

    • if no, two conversions are needed

  • issues of format, syntax within ONE GIS

Midterm next wednesday

  • Digital Line Graphs (DLGs)

    • vector topographic maps

    • 1:24,000, 1:100,000 ,1:10,000

Govt agency data formats

Govt Agency Data Formats

  • Digital Raster Graphics (DRGs)

    • raster topographic maps at 1:24,000

  • Digital Elevation Models (DEMs)

    • raster elevation data

    • 90m, 30m, 10m

    • Oregon 10m DEMs from buccaneer.geo.orst.edu/dem

Govt agency data formats1

Govt Agency Data Formats

  • Digital Orthophoto Quads (DOQs or DOQQs)

    • aerial photographs

    • camera orientation, terrain info.

    • raster images at 1m resolution

    • 6m positional accuracy at scale of 1:12000

  • Imagery

    • satellites

    • Landsat, SPOT, SPIN, etc.

National data sharing cont

National Data Sharing (cont.)

  • new high resolution commercial imagery

  • 1 m resolution

  • www.spaceimaging.com

Barriers to data sharing1

Barriers to Data Sharing

(2) how to describe what you need

  • how to assess whether some data set fits the need?

Describing data

Describing Data

  • Metadata

  • Again, see GEO 465/565 lecture #6

    • dusk.geo.orst.edu/gis/lec06.html#nsdi

  • ArcCatalog

    • graphic thumbnail

    • Tables

    • FGDC format metadata

    • ESRI format metadata

    • XML format metadata

Issues with metadata

Issues with metadata?

  • potential complexity

    • can be larger than the data set!

  • investment to create

    • can be larger than the data set!

  • carrots and sticks

    • FGDC’s "don't duck metadata"

Barriers to data sharing2

Barriers to Data Sharing

(3) retrieval - large spatial data sets

(4) national security - e.g., impact of 9/11

(5) search engines

  • how to know where to look on the WWW?

  • SAPs know where to look (more on this soon)

    • National clearinghouse, www.geodata.gov/ or geographynetwork.com

    • Regional and campus clearinghouses,

    • www.geo.oregonstate.edu/ucgis/datasoft.html

    • Google

Finding data

Finding Data

  • How to find geospatial data on the WWW

    • 10,000,000 servers worldwide and quickly rising

    • containing order 1x 1015 bytes of information

    • several servers contain more than 1 x 1012 bytes of geospatial information (terabytes)

  • WWW search engines

    • Google, Yahoo, Ask Jeeves, Hot Bot, AltaVista

    • send out “spiders” to find pages

    • find the most important words in pages

    • build a catalog of words

    • how many pages contain the word "map”?

Finding data cont

Finding Data (cont.)

  • most important metadata element is geographic location

    • find me some data about area x

    • only some areas have names

      • what if there's no name for the area you want?

    • only some hits on a name lead to geospatial data

      • search engines work on text, not GIS data sets

Some searching solutions

Some Searching Solutions

(1) Know whereto look for a particular type of data

  • ortho.mit.edu contains a lot of DOQ data for Massachusetts

  • Valley library has free DOQ data for Oregon

  • osulibrary.orst.edu/research/guides/maps/


  • USGS geospatial data is at the Eros Data Center, edc.usgs.gov

  • 1 types of data cont

    (1)Types of Data (cont.)

    • Microsoft's Terraserver contains DOQs and Russian imagery

      • www.terraserver.microsoft.com

      • >1 terabyte

      • millions of hits per day

    • EPA data, www.epa.gov

      • Corvallis ecoregion data at www.epa.gov/wed/pages/ecoregions/


    • Again, only SAPs know this stuff ...

    Some searching solutions cont

    Some Searching Solutions (cont.)

    (2) Go to a clearinghouse site

    • www.geodata.gov

      • Over 300 servers

      • Common metadata format, FGDC standard

      • must select (multiple) servers to search

    • Regional node of NSDI

      • Oregon Coastal Atlas, www.coastalatlas.net

    Some searching cont

    Some Searching (cont.)

    (2) Go to a clearinghouse site

    • many states have government-sponsored clearinghouses

      • Oregon Geospatial Data Clearinghouse

      • www.oregon.gov/DAS/EISPD/GEO/alphalist.shtml

    • Campus clearinghouses

      • www.geo.oregonstate.edu/ucgis/datasoft.html

    • ESRI-sponsored data sites

      • Geography Network, www.geographynetwork.com

    Some searching solutions cont1

    Some Searching Solutions (cont.)

    (3) Go to a digital library

    a digital library whose contents are searchable by geographic location

    • National Academy of Sciences report Distributed Geolibraries (1999)

      • using a map

      • using a placename directory

      • using coordinates

      • what have you got about there?

    Digital libraries cont

    Digital Libraries (cont.)

    • specify area of interest as a box on a map

    • or one of millions of placenames

    • how do I know that the library is likely to have what I want?

      • collection level metadata

      • a description of the contents of a collection

    Digital libraries cont1

    Digital Libraries (cont.)

    • OSU’s Oregon Explorer

      • oregonexplorer.info

    • UCSB’s Alexandria Digital Library

      • www.alexandria.ucsb.edu

      • Part of California Digital Library

      • over 2,500,000 data sets

    Some searching solutions cont2

    Some Searching Solutions (cont.)

    (4) Issue-oriented site …


    Download and use Darfur KML from course lecture page

    Who knows where Google will go with sites such as this?

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