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 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.

Concepts of Data Sharing Longley et al., Chapter 11

NSDI ---> data.gov 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

NSDI ---> data.gov 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 of geospatial data See GEO 465/565 lecture #6 –dusk.geo.orst.edu/gis/lec06.html#nsdi

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

Digital Line Graphs (DLGs) –vector topographic maps –1:24,000, 1:100,000,1:10,000

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

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. Govt Agency Data Formats

National Data Sharing (cont.) new high resolution commercial imagery 1 m resolution

Barriers to Data Sharing (2) how to describe what you need –how to assess whether some data set fits the need?

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? 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 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, Regional and campus clearinghouses Google