The Census Bureau collects extensive numeric data on the residents of the United States as well ast the national economy. This is accomplished both through a decennial census as well as numerous other more frequent surveys. The decennial census is a fundamental basis of American democracy, mandated by the U.S. Constitution and essential for the equal representation in a democratic government. Numeric census data are maintained in vast collections of tables and organized at many different levels of geographies. From the Census website, the geographic and tabular data can be downloaded and then joined for display and analysis within a GIS. Because of the nature of individual data aggregated over areas and other matters, care must be taken to avoid statistical errors when undertaking spatial analyses.
The capture of massive quantities of spatial data, able to be distributed and shared in real time, provide for an ever-increasing range of environmental and societal applications. Data capture includes the principles, methods, technologies, applications, and institutional/programmatic aspects of spatial data acquisition. Sources of data include global navigation satellite systems, satellite and aerial sensing, field surveys, land records, socioeconomic data (e.g., census), volunteered geographic information, wireless sensor networks, and unmanned aerial systems.
Topics in this Knowledge Area are listed thematically below. Existing topics are in regular font and linked directly to their original entries (published in 2006; these contain only Learning Objectives). Entries that have been updated and expanded are in bold. Forthcoming, future topics are italicized.
|History & Trends||Processing Remotely-Sensed Data|
|Changes in Data Capture Methods Over Time||Image Interpretation: Aerial Photography & Satellites|
|Georeferencing and Georectification||Feature Extraction in Satellite Imagery|
|Digital Data Sources & Capture Methods||Ground Verification and Accuracy Assessment|
|Historical (Paper) Maps||Spectral Properties of Terrestrial Surfaces|
|Global Navigation Satellite Systems||Structure from Motion Photogrammetry|
|Mobile Applications||GIS and Surveying|
|Aerial Photography: History & Georeferencing||Professional Land Surveying|
|Ground or Street-Level Imagery||Land records|
|Social Media Platforms||Ocean Surveying|
|Volunteered Geographic Information (VGI)||Field Data Collection|
|Remote Sensing Platforms & Sensors||Sampling: Size Selection, Sample Types, Intervals|
|Remote Sensing Platforms overview||Field Data Capture Technologies|
|Nature of multispectral image data||U.S. Census Data|
|Unmanned Aerial Systems (UAS)||Data Coordinating Organizations|
|Landsat||Multi-Organizational GIS Coordination|
|Light Detection and Ranging (LiDAR)||Federal Agencies & National Organizations and Programs|
|Indoor LiDAR Scanning||International Organizations & Programs|
|Radar, Sonar, and Echolocation|
|Airborne LiDAR Bathymetry|