1 / 17

Data Sharing

Data Sharing. We all need data There are a huge number of different types of data Needs: Right theme Right Area of Interest (AOI) Right precision and accuracy Compatible format. Challenges. Performance: Local will always be faster GIS datasets can be huge Projection on the fly is slow

suzy
Download Presentation

Data Sharing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Data Sharing • We all need data • There are a huge number of different types of data • Needs: • Right theme • Right Area of Interest (AOI) • Right precision and accuracy • Compatible format

  2. Challenges • Performance: • Local will always be faster • GIS datasets can be huge • Projection on the fly is slow • Formats: • New ones are typically too complex • Documentation • Typically the data is available with little documentation • Little or none on accuracy and precision

  3. US Datasets • National Hydrology Dataset (NHD) • National Elevation Dataset (NED) • Digital Raster Graphics (DRGs) • Digital Line Graphics (DLGs) • Digital Ortho-Quarter Quads (DOQQs) • NOAAs new electronic charts? • NationalAtlas.gov

  4. Digital Raster Graphics (DRG)

  5. Digital Line Graphs (DLG)

  6. 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

  7. Vector Data Formats • Point-Specific Formats • Tab-delimited Text • Comma separated values • General Vector Formats • Shapefiles: Really popular • Coverages: Going away? • SDTS: Future uncertain at best? • Scalable Vector Graphics: Not geo-referenced • KML: Widely used, becoming a GIS standard

  8. Raster Formats • Tagged Image File Formats: TIFF • ASCII Grid: Widely used • Imagine: IMG • Ersi Grid: Being replaced by IMG? • JPG: Georeferenced with world file and prj • BIL, BIP, BSQ: and other “binary” formats • All have a “header” file (HDR)

  9. Hierarchical Data Formats • Hold the promise of a single “self-describing” data file • So far the promise has not been met • NetCDF converters now in ArcGIS • Examples: • Hierarchical Data Format: HDF • Network Common Data Form: netCDF

  10. Promise of the “Cloud” • What is the cloud? • Lots of servers on the Internet providing “services” • Promise: • Universal access to data • High-performance • High-quality • Reality: • Lots of problems with compatibility • Typically slow • Questionable to undocumented quality

  11. The Cloud • Esri’s Backgrounds • Great if you use the background’s spatial reference and have strong Internet connection • Problems: • Cut-off labels • Projecting on the fly • Slow Internet connection

  12. Shared Storage Successes • Shared network drive • Can be on a workstation • Define the folder organization! • Make sure it is backed up • DropBox for Teams • Maintains local copies • Trying it out with OSU/DOE research team

  13. Types of GIS Data Websites • Map-based • Can be hard to use • Processing data takes time and lots of complexity • See NationalMap, EarthExplorer • Right click to “save target as” • See NationalAtlas.gov

  14. Metadata • ISO 19115:2003 • Geographic information - metadata • The Federal Geographic Data Committee (FGDC) • Content Standard for Geospatial Metadata • Being superseded by North American Profile (NAP) of ISO 19115:2003 • ISO/TS 19139:2007 • XML Implementation of ISO 19115

  15. ArcGIS • Maintains their own metadata format • Import/Export to and from other formats • ArcToolbox -> Conversion Tools -> Metadata

  16. ArcGIS

  17. Jim’s Recommendation • Use and contribute to a “Directory of GIS Web Resources” • See ibis.colostate.edu • When publishing data: • Add at least the required metadata (including accuracy and precision) • Publish on simple web page with links to zipped data in common file formats

More Related