Remote sensing means acquiring and measuring information about an object or phenomenon via a device that is not in physical or direct contact with what is being studied (Colwell, 1983).To collect remotely sensed data, a platform – an instrument that carries a remote sensing sensor – is deployed. From the mid 1800’s to the early 1900’s, various platforms such as balloons, kites, and pigeons carried mounted cameras to collect visual data of the world below. Today, aircraft (both manned and unmanned) and satellites collect the majority of remotely sensed data. The sensors typically deployed on these platforms include film and digital cameras, light-detection and ranging (LiDAR) systems, synthetic aperture radar (SAR) systems, and multi-spectral and hyper-spectral scanners. Many of these instruments can be mounted on land-based platforms, such as vans, trucks, tractors, and tanks. In this chapter, we will explore the different types of platforms and their resulting remote sensing applications.
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.
|Digital Data Capture||Land Surveying and GPS|
|Data capture methods||Survey theory and electro-optical methods|
|Aerial Imaging||Global Positioning System|
|Nature of aerial photograph data|
|Aerial photography image interpretation||Field Data Collection|
|Spatial sample types|
|Remote Sensing Platforms & Sensors||Sample size selection|
|Mission planning||Sample intervals|
|Nature of multispectral image data||Census data|
|Multispectral sensors and programs||Field data technologies|
|LiDAR data||Volunteered Geographic Information (VGI)|
|Unmanned Aerial Systems (UAS)|
|Data Coordinating Organizations|
|Spatial data sharing among organizations|
|Processing Remotely-Sensed Data||Federal agencies, National & International Organizations|
|Stereoscopy and orthoimagery||State and regional coordinating bodies|
|Vector data extraction|
|Algorithms and processing|
|Ground verification and accuracy assessment|