Introduction to GISystems and GIScience

Study Notes

What is a GIS?

A GIS is a system that uses hardware, software, and data to analyze and display geographically referenced information it has a specific purpose or goal.
It analyzes and displays spatially-referenced data.
It has different functions or views, including:
- Database View: Stores data.
- Map View: Provides a visual representation of the data.
- Model View: Shows relationships between different elements.
A GIS comprises:
- Geographic space: Visual representation using coordinates.
- Data space: Attribute table containing information about the data.

GISystems vs GIScience

GISystems refer to the tangible components of a GIS: hardware and software.
GIScience deals with the theoretical aspects of GIS, including metadata tools, theories, and analysis techniques.

Goals of GIS

Make geographic information more meaningful for users.
Extract quantitative information from maps, images, and tables.
Transform information, knowledge, evidence, and wisdom.

GIS Data

General data: Observations or measurements obtained from the real world.
Spatial data (geospatial data): Any data that has a location attached.
- Organization of Spatial Data
  - Thematic Data Layers: Work horizontally or vertically, held together by a coordinate system.
- Spatially-Referenced Data:
  - Important for:
    - Using services.
    - Emergency response.
    - Business training systems.
  - Categorization:
    - Census geography.
    - Geocoding.
    - Spherical and planar coordinates.
Metadata: Explanatory information about the data that guides users.
- Data is less valuable without interpretable metadata.
Data Quality:
- Precision: The ability to replicate a measurement.
- Accuracy: The trueness of the data value or how close it is to the 'ideal value of the object'.

Representing Geographic Space

Vector GIS: Represents data as points, lines, and polygons.
- Objects:
  - Three types:
Polygons:* Have unique IDs and are stored in the attribute table. They are a closed series of points connected by lines so that the start and end points are the same. They hold a defined area.
Lines:* A series of connected points which form a line.
Points:* Points with a label and identification number. - Topology: How objects are connected to each other.
- Resolution and scale are important for accurately representing objects.
- Links between objects and attribute tables are essential for a functional GIS
Raster Cells: Labelled cells on a grid.
- Smaller cells create more detail (higher resolution), leading to greater accuracy, but larger files.

Description

This quiz explores the fundamental concepts of Geographic Information Systems (GIS), including the distinction between GISystems and GIScience. Learn about the different views and components of GIS, and understand its goals in making geographic information meaningful. Test your knowledge on these crucial aspects of GIS technology.