A GIS is comprimised of hardware, software, data, humans, and a set of organizational protocols. Bolstad (2003)

GIS is an "organized activity by which people measure and represent geographic phenomena and then transform these representations into other forms while interacting with social structures." Chrisman (1999)

Curious and Sharing

As humans, we seek look for patterns in nature and seek a holistic understanding of our environment. We share knowledge and discoveries in many ways including written words, drawings and diagrams, and verbally. Our ability to convey knowledge and find patterns is increasing as new tools and technologies emerge.

People are natural explorers and constantly seek to identify aspects of nature to explore and understand. In the process of our explorations, we are continually inventing and improving upon tools to aide our efforts. We share knowledge about our tools, techniques, and understanding in order to benefit our peers and build community.

Community Geospatial

Community Geospatial is a values based approach to systems thinking and environmental awareness. Values such as collaboration, sharing (open data, open formats), stewardship, communication, equality, and participation are among the ideals engendered by the Community Geospatial movement.

Community geospatial systems consist of people using tools to share and analyze information.The information will typically, but not always, have a geographical component (or spatial reference). Additional information, known as attributes, may be linked or related to geographic data.

For example, biologists track animal movements around their habitat and often over the course of many months or years. The biologists will collect information describing species locations as well as extra attributes including color, size, quantity, etc, that may not be specifically geographic (or spatial).

Maps and Attributes

Our goal with CGIS is often to produce maps and other visualizations of interrelated data in order to support community decision making process. Maps are usually two dimensional representations of our understanding of a geographic, or conceptual, area. These maps will contain various text and graphic markings. Markings are usually in the form of points, lines, and areas (polygons). Graphics comprised of points, lines, and polygons are called vector images.

Image Data

Other images may be integrated into a GIS project. These images are comprised of a grid of pixels where each pixel represents a color value at that point. This type of image is called a raster image. Examples of raster images include satellite, or aerial, imagery, hand drawn maps, and kite photography.

Location

Location is the key aspect that differentiates Community Geospatial from other forms of data collection. Every point, line, polygon, and image is linked to geographic location(s). Locations are usually represented by coordinates, such as (x,y).

A geographic coordinate system allows any point on earth to be represented by a set of numbers. Common coordinates include the latitude and longitude system, which uses hours, minutes, and seconds to represent points.

Core Concepts

There are several important concepts and components of geospatial processes and systems.

• Shapes (Vector data)
  • points
  • lines
  • polygons
• Images (Raster Data)
• Location
  • Coordinate systems
  • latitude, longitude, parallels, meridians
• Distance
  • Traveling Distance
  • Great Circle distance
• Units
• Projections
• Datums
• Metadata
• Attributes