Geodatabase structure

ATTRIBUTES

Pixel Centers Pixel Polygons Coded Pixels

Preparing for "what3words" as True Big Data Meets Unique Pixels - an NLCD Pixel Grid Index for Kentucky

ABSTRACT

Pixel identity is relevant to current efforts such as unique addressing and place-centric GIS (http://what3words.com/), and citizen science initiatives (https://lta.cr.usgs.gov/adopt_a_pixel).

Cartographically harmonized National Land Cover Databases (NLCD2001, NLCD2006, and NLCD2011) created by the Multiresolution Land Characteristics Consortium (http://www.mrlc.gov/nlcd11_data.php) now afford an opportunity to develop an index grid with unique NLCD pixel identifiers for the Commonwealth of Kentucky.

File geodatabases containing pixel grid vector data (pixel centers and polygons), and pixel grid raster masks were derived from the NLCD in its native coordinate system (Albers Equal Area Conic – USGS parameters; NAD83), by extraction using the re-projected Kentucky Boundary (http://kygisserver.ky.gov/geoportal/catalog/search/resource/details.page?uuid=%7B32B89F6C-95AA-4B5EA15E-43E835D3D113%7D).

The resulting one hundred sixteen million 30-meter pixels were coded as belonging to three different types:

1- wholly inside Kentucky;

2 – intersecting the boundary but with center inside Kentucky; and

3 – intersecting the boundary but with center outside Kentucky.

Demetrio P. Zourarakis, PhD, GISP, CMS-RS, CMS-GIS/LIS GIS and Remote Sensing Analyst, Kentucky Division of Geographic Information

Background

Growing ‘Citizen Scientist’ Movement

Array of mobile devices and apps utilize geolocation and geographic contextualization for science teaching/learning purposes – the ‘crowdsourcing’ and ‘volunteered geographic information’ crowd

Bold initiatives: “Adopt a Pixel” (https://lta.cr.usgs.gov/adopt_a_pixel) and what3words (http://what3words.com/) are examples of ‘hyperlocal’ geographic/spatial/’placial’ awareness

‘Big Data’ are pervasive in geospatial science and technology

Sensor data derivatives are codified as arrays of square pixels on projected map space

Map projections are problematic concepts to communicate and are implicit in mapping accuracy

Mapping standards of individual agencies are disparate

Pixel-based indexing is rare – in favor of more popular tile-based indices

State Plane Coordinate System (FIPS 1600)

KY Single Zone

Geographic Coordinate System – NAD 83

USGS – Contiguous Albers Equal Area Conic

NLCD 2011 – USGS – Contiguous Albers Equal Area Conic

References

- Bunch, B. W. 2004. The Kentucky Single Zone State Plane Coordinate System. URL: http://transportation.ky.gov/Highway-Design/Documents/Kentucky Single Zone.ppt. Last accessed: 1/27/16. - Division of Geographic Information (DGI-a). 2016. The Kentucky Coordinate System of 1983. URL: ftp://kygeonet.ky.gov/kygeodata/standards/Ky_StatePlane.pdf. Last accessed: 1/27/2016. - Division of Geographic Information (DGI-b). 2016. Image Services – KY_NLCD_2011_30M. URL: Division of Geographic Information. 2016. The Kentucky Coordinate System of 1983. URL: http://kyraster.ky.gov/arcgis/rest/services/ImageServices/Ky_NLCD_2011_30M/ImageServer. Last accessed: 1/27/2016. - Division of Geographic Information (DGI-c). 2016. The 8, 10 and 12 digit hydrologic unit boundaries for Kentucky (FGDC) / hydrologic_units_81012 (ISO). URL: http://kygisserver.ky.gov/geoportal/catalog/search/resource/details.page?uuid=%7B1AC9E2AC-C4CF-4D68-8CBF-3D8E4EC25119%7D. Last accessed: 1/27/2016. - GeoRepository. 2016. Projected CRS used in USA – Kentucky. URL: http://georepository.com/crs_3088/NAD83-Kentucky-Single-Zone.html. Last accessed: 01/27/16. - Kentucky Administrative Regulations (KAR). 2016. 10 KAR 5:-010. The Kentucky Single Zone Coordinate System of 1983. URL: http://www.lrc.ky.gov/kar/010/005/010.htm. Last accessed: 1/27/2016. - Kentucky Regulatory Statutes (KRS-a). 1992. KRS 1.020 Kentucky Coordinate System of 1983. URL: http://www.lrc.ky.gov/statutes/statute.aspx?id=2. Last accessed: 1/27/2016. - Kentucky Regulatory Statutes (KRS-b). 2012. KRS 42.650 Division of Geographic Information Systems – Powers and duties – Authority for administrative regulations. URL: http://www.lrc.ky.gov/Statutes/statute.aspx?id=40262. Last accessed: 1/27/2016. - Multi-Resolution land Characteristics Consortium (MRLC). 2016. National Land Cover Database 2011 (NLCD 2011). URL: http://www.mrlc.gov/nlcd2011.php Last accessed: 01/27/16. - Nagi, R. 2010. On map scale and raster resolution. URL: https://blogs.esri.com/esri/arcgis/2010/12/12/on-map-scale-and-raster-resolution/. Last accessed: 01/27/16. - United States Geological Survey (USGS). 2013. Decision Support System for Map Projections of Small Scale Data. URL: http://mcmcweb.er.usgs.gov/DSS/ImgHTML/Albers.html. Last accessed: 01/27/16.

State Plane Coordinate System (FIPS 1600) – KY Single Zone

Geographic Coordinate System – NAD 83

USGS – Contiguous Albers Equal Area Conic

Example: SPCS KY Single Zone