Midterm next Wednesday Midterm May start off with

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. • 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) • Desktop to Cloud Discussion

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/lec 06. html#nsdi

Barriers to Data Sharing (1) interoperability – will Arc. GIS 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 – 90 m, 30 m, 10 m – Oregon 10 m DEMs from buccaneer. geo. orst. edu/dem

Govt Agency Data Formats • Digital Orthophoto Quads (DOQs or DOQQs) – aerial photographs – camera orientation, terrain info. – raster images at 1 m resolution – 6 m positional accuracy at scale of 1: 12000 • Imagery – satellites – Landsat, SPOT, SPIN, etc.

National Data Sharing (cont. ) • new high resolution commercial imagery • 1 m resolution • www. spaceimaging. com

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/lec 06. html#nsdi • Arc. Catalog – 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, www. data. gov Regional and campus clearinghouses www. geo. oregonstate. edu/ucgis/datasoft. html Google