GIS
Terms
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- What are some of the roles of GIS?
- Technology, Methodology, Discipline, Profession, Business, Paradigm
- What is a projection?
- The process of systematically transforming positions on the Earth's spherical surface to a flat map while maintaining spatial relationships. UTM and SP are common projection systems.
- what are some of the functions of GIS?
- Collection, Storage and Management, Retrieval, Conversion, Analysis, Modeling, Display
- What are the types of GIS data?
- spatial, aspatial, discrete, continuous
- What are the measures of data quality?
- MGD SCAPE: Metadata, Generational, Derived, Scale, Consistency, Accuracy, Precision, Error
- What are the different types of database structures?
- Flat file, Hierarchical, Relational
- What is meant by a data quality error?
- This is a discrepency between recorded and true data.
- What is meant by data quality Accuracy?
- This is the truth or validity of data according to reality.
- What is a flat file?
- single table, no relationships
- What is meant by data quality Precision?
- This is the level of detail in the data.
- What is meant by data quality scale?
- This is the ratio between the model and the real world distances.
- what is a hierarchical table?
- nested tables, one-to-one and one-to-many relationships
- What is meant by data quality consistency?
- This is the agreement of features to one another or to a whole.
- what is a relational table?
- Interrelated tables, one-to-one, one-to-mny, many-to-one, and many-to-many relationships
- what is a Raster data model?
- Location is referenced by a grid cell in a retangular array or matrix. Attribute is represented as a single value for that grid cell. It is best for continuous data, such as elevation or temperature.
- What is a vector data model?
- Location is referenced by x,y coordinates which can be linked to form lines and polygons. Attributes reference through unique ID number to tables. Vector is best for use with features that have discrete boundaries, such as soil type and land use.
- What is meant by generational data?
- This is data which has been repeatedly reproduced.
- What is the definition of topology?
- The properties of an object that are unaffected by continuous distortion. In GIS terms it is the set of spatial relationships between features in terms of: line connectivity, feature definition, and polygon contiguity. Note: Only applies to Vector Data!!!
- What is meant by derived data?
- This is data which has been systematically translated.This is data which was made from other data.
- What are some GIS data sources?
- maps, field data, digital products, tabular data, reports, human input, remote sensing, address geocoding, GPS
- What qualities about data will metadata inform?
- Identification (title, area, owner, Organization); Data Quality; Spatial Data Organization (Raster or Vector, Structure of fetures in model); Spatial Georeferencing; Features & Attributes (database definitions, codes and categories); Distribution (how to obtain data, contacts and fees)
- What is georeferencing?
- Identifying locations on the earth using locations on a map or GIS.
- What are the aspects of georeferencing?
- Coordinate systems, Datum, Projections
- What is a coordinate system?
- this is a location system using an (x,y) grid to permit accurate Earth location of a feature, i.e. latitude, longitude
- What is the definition of GIS?
- A computer based technology and methodology for collecting, managing, analyzing, modeling and presenting data for a wide range of applications.
- What is a datum?
- This is the origin point for a coordinate system. NAD27 for example.
- What are some of the roles of GIS
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-infrastructure management
-transportation network routing
-floodplain management
-noise pollution analysis
-emergency response planning
-jobs/housing spatial balance