What is remote sensing?
Remote sensing is the science of obtaining information about objects or areas from a distance, typically from aircraft or satellites.
Remote sensors collect data by detecting the energy that is reflected from Earth. These sensors can be on satellites or mounted on aircraft.
Remote sensors can be either passive or active. Passive sensors respond to external stimuli. They record natural energy that is reflected or emitted from the Earth's surface. The most common source of radiation detected by passive sensors is reflected sunlight. In contrast, active sensors use internal stimuli to collect data about Earth. For example, a laser-beam remote sensing system projects a laser onto the surface of Earth and measures the time that it takes for the laser to reflect back to its sensor.
Remote sensing has a wide range of applications in many different fields:
- Coastal applications: Monitor shoreline changes, track sediment transport, and map coastal features. Data can be used for coastal mapping and erosion prevention.
- Ocean applications: Monitor ocean circulation and current systems, measure ocean temperature and wave heights, and track sea ice. Data can be used to better understand the oceans and how to best manage ocean resources.
- Hazard assessment: Track hurricanes, earthquakes, erosion, and flooding. Data can be used to assess the impacts of a natural disaster and create preparedness strategies to be used before and after a hazardous event.
- Natural resource management: Monitor land use, map wetlands, and chart wildlife habitats. Data can be used to minimize the damage that urban growth has on the environment and help decide how to best protect natural resources.
Article source: NOAA. What is remote sensing? National Ocean Service website, https://oceanservice.noaa.gov/facts/remotesensing.html, Jan. 20, 2023
Aerial Photography
Aerial photography of Delaware dating back to 1937 is available for download for the entire state. Aerial views from 1926 are available for selected areas, including Wilmington, Newark, and other sites in Delaware.
- DEMAC Aerial PhotographyThe State of Delaware has flown (or has acquired) aerial orthophotography from various times since 1926 and has been offering these images publicly for a number of years. The data is distributed from DEMAC as individual files (per tile) and from Delaware FirstMap as Image Rest Services.
- Dallin Aerial Survey Company Photographs : Hagley Digital ArchivesDigitized images date from 1924-1941 and include over 7,500 of the approximately 12,000 images in the Dallin Aerial Survey Company collection. The majority of the photographs concentrate on the Mid-Atlantic region.
- Pennsylvania Spatial Data Access (PASDA)Pennsylvania's official public access open geospatial data portal.
- National Land Imaging Program (USGS)The fundamental goal of the NLI Program is to provide the Federal Government and the public with a primary source of remotely sensed data and applications and to be a leader in defining the future of land remote sensing, nationally and internationally.
- Wisconsin Historic Aerial Image FinderThe Wisconsin Historic Aerial Image Finder provides free online access to over 38,000 aerial photographs of Wisconsin from 1937-41. These photographs were originally acquired by the US Department of Agriculture. As part of a three-year project funded by the Ira and Ineva Reilly Baldwin Wisconsin Idea Endowment at the University of Wisconsin-Madison, these photographs were scanned, indexed, and made web-accessible through a map-based interface. These photographs are available for download by any user without fee or use restrictions.
- Digital Coast | NOAAWebsite provides coastal data (from economic data to satellite imagery), and contains visualization tools, predictive tools, and tools that make data easier to find and use. Content comes from many sources, all of which are vetted by NOAA.
- Aerial Photography: FloridaThe University of Florida Map & Digital Imagery Library houses the largest and most complete collection of Florida aerial photographs outside of the National Archives. Coverage: 1937 and 1990.
- Ariel Photography | APFONOTE: The Aerial Photography Field Office (APFO) website content has moved to Farm Production and Conservation (FPAC) Geospatial Enterprise Operations (GEO). Please visit the new FPAC Geospatial Enterprise Operations (GEO) website.
- Imagery Catalogs | Farm Production and Conservation Business CenterFind files for locating available aerial imagery. Coverage used by the U.S. Department of Agriculture (USDA) from 1955 to the present.
- Landsat 8 Data | USGSData products created from Landsat 8 OLI/TIRS scenes are available to download from EarthExplorer, GloVis, and the LandLook Viewer.
- Landscape Histories from the Air | Cambridge University LibraryThis collection of Aerial Photographs comprises 497,079 aerial images dating from 1945 to 2009, and includes both vertical and oblique aerial views of British landscapes, in both black and white and colour, and slides.
Online
- Data.gov | DatasetsSearch the Data.gov catalog to find geospatial information using the filter Dataset Type: geospatial
- EarthExplorer | USGSEarthExplorer is a search engine for data sets, including formerly classified data. Some images are available no fee while others must be purchased.
- Google EarthExplore worldwide satellite imagery and 3D buildings and terrain for hundreds of cities.
- Landsat Gallery Space | NASALandsat satellites record the spectral story of Earth’s land surfaces and near-shore coastal waters. Explore the images in such collections as Earth As Art, Visible Earth, and Scientific Visualization Studio.
- NASA WorldWindWorldWind is an open source virtual globe API. WorldWind allows developers to quickly and easily create interactive visualizations of 3D globe, map and geographical information. Organizations around the world use WorldWind to monitor weather patterns, visualize cities and terrain, track vehicle movement, analyze geospatial data and educate humanity about the Earth.
- Earth Data | Earth Observation Data (NASA)Earthdata Search enables data discovery and access to more than 33,000 Earth observation data collections from NASA’s EOSDIS (Earth Observing System Data and Information System). Resources also available to learn ow to find, use, and visualize the datasets.
- Rutgers: Center for Remote Sensing and Spatial Analysis"Rutgers University, has generated digital geospatial data, technical reports, maps/galleries, and more in support of various on-going and past research, projects, and programs." They also have a significant list of other sources of Geo-spatial data.
- Maps & Geospatial services | United NationsFind a variety of maps: general or profile maps, thematic products, earth observations and imagery, and digital archives which cover a wide range of topics including decolonization, the environment, health, peacekeeping, climate change, socioeconomics, and human rights.
- USGS Global Visualization Viewer"The USGS Global Visualization Viewer is a quick and easy online search and order tool for selected satellite and aerial data." This site requires the use of popup windows
- Visible EarthA catalog of NASA images and animations of our home planet. Users may browse by satellite, sensor, collections, country, U.S. State, or Global Change Master Directory (GCMD) topic.