Spatial data and representations Flashcards
Describe data
- physical/abstract facts/observations about real world phenomena
- derived thru cognitive processes (selection > generalization > synthesis)
- dependent on observer’s perceptions
What is the DIKW pyramid
Data > Information > Knowledge > wisdom
What can GIS do to turn data into information?
processing, manipulation and presentation of data to create information.
What are the 3 ways of conceptual representations?
- object view (distinct boundaries and shapes, vector)
- field view (raster, everything has a value)
- network view (extension of object view, connected objects, i.e. hydro lines)
Explain the special aspects of spatial data
- links many attributes (place, time, attributes)
- needs lots of storage
- heterogenous (many users and providers)
- scale dependencies
- uncertainties
What is DMBS?
Database management systems (software that lets users access DBS and manipulate data)
How do foreign keys work?
-foreign keys are fields that contain values found in another table’s primary key, and are used to link tables together
Briefly explain file-based spatial data structures
- essentially shapefile/things like shapefiles
- used for small/medium projects and available in many formats
- simple to setup, share, just a zipped-up shapefile
- but if one file is corrupted, then all is corrupted, hard to enforce security
- only 1 person can make changes at a time
Briefly explain rational database management system
- for larger sized orgs (i.e. accounting, payroll)
- good for volume, good security, many users at once, robust backup and maintenance routines, distributed storage
name the 3 types of data storage
- shapefile
- coverage
- geodatabase
What is the function of Open Geospatial Consortium?
-sets standards for geo data to enable interoperability: connect to different appliances.
