Getting Started with Data Management Flashcards
Spatial components of GIS
o Visualize real world information and analytical output
o Implement analytical functions such as proximity analysis, buffering, and movement
o Select and filter features geographically
o Calculate properties such as length and area
Two main types of GIS Data
Raster and Vector
Vector data
Is comprised of geometry and attributes. Geometry can be points, lines, or polygons that represent real world features. Attributes provide information about these real-world features.
The most basic type of vector data?
Point data
Line
features use a set of vertices to draw each line
Polygon
Like line features, polygon features use a set of vertices to draw each shape. However, the lines created by a set of vertices are closed for polygon features.
Raster data
o a grid or matrix of uniformly sized cells.
o composed of grids of cells, with each cell containing a value for a particular phenomenon or observation
Derived rasters
ArcGIS can create derived raster products that add context and value. This higher resolution raster contains values for elevation. Based on this elevation value, ArcGIS has calculated slope and aspect for each given point. Visually, the raster has been rendered to show elevation and hillshade. These values are created on-the-fly; rasters do not have attribute tables.
Coordinate systems
o sets of geographic grids that provide a structured way of communicating geographic location.
o Location is represented by a set of x,y coordinates, often a set of degrees in latitude and longitude.
Metadata
Information that makes it easier to search for and discover appropriate data: a description of the data or content and its intended use, the author, the date that the data was made and modified, descriptive tags
Domains
You can use ______ to constrain the valid values for a particular field. Attribute _______ allow you to set a list of options that help prevent errors being introduced when users add or edit attribute values.
a subset of features that share the same attributes
Subtypes
Connectedness, adjacency, and proximity between features can be summed up in one word: ________. ________ allows you to define the spatial relationships that you want protected in your GIS data. By doing so, no matter how much you edit, twist, bend, or squash your feature data, the features stay connected to, adjacent to, or within the areas that they belong to.
Topology
Archiving Data
o Archiving versioned data allows you to record and access changes to data. Archiving allows temporal analytical capabilities by documenting data changes over time.
o Archiving can help answer the following questions:
o How have features changed shape over time, such as a wastewater network being reworked to accommodate a city’s continued growth?
o How have attributes changed, such as zoning or parcel ownership?
You are creating a streets dataset. You want to constrain the Types field to local roads, highways, and off-ramps. Which data behavior would you use?
Domains
