Glossary: D

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  1. A collection of facts, concepts or instructions in a formalized manner suitable for communication or processing by human beings or by computer. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  2. A logically meaningful grouping or collection of similar or related data. Data having mostly similar characteristics (source or class of source, processing level and algorithms, etc.) Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  3. Shedding leaves at the end of the growing season. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  4. Official issuance of a state of emergency or calamity upon the occurrence of a large-scale event (hazard), in order to activate measures aimed at responding to the needs arising as a consequence of the disaster. The declaration of a disaster by a...
  5. The angular distance from the equator to the satellite, measured as positive north and negative south. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  6. Those practices or processes that result in the change of forested lands to non-forest uses. This is often cited as one of the major causes of the enhanced greenhouse effect for two reasons: 1) the burning or decomposition of the wood releases...
  7. A unit of angular measure represented by the symbol o. The circumference of a circle contains 360 degrees. When applied to the roughly spherical shape of the Earth for geographic and cartographic purposes, degrees are each divided into 60 minutes....
  8. The fan-shaped area at the mouth or lower end of a river, formed by eroded material that has been carried downstream and dropped in quantities larger than can be carried off by tides or currents. Source: NASA (http://earthobservatory.nasa.gov/...
  9. Process by which water changes phase directly from vapor into a solid without first becoming a liquid. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  10. The point in a satellite's orbit at which it crosses the equatorial plane from north to south. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  11. A land area so dry that little or no plant or animal life can survive. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  12. The man-made or natural formation of desert from usable land. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  13. A device in a radiometer that senses the presence and intensity of radiation. The incoming radiation is usually modified by filters or other optical components that restrict the radiation to a specific spectral band. The information can either be...
  14. Accumulated organic debris from dead organisms, often an important source of nutrients in a food web. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  15. In signal processing this refers to the representation of quantities in discrete units. The information is contained and manipulated as a series of discrete numbers as opposed to an analog representation where the information is represented as a...
  16. A representation of the topography of the Earth in digital format, that is, by coordinates and numerical descriptions of altitude. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  17. A serious disruption of the functioning of society, causing widespread human, material or environmental losses which exceed the ability of the affected society to cope using only its own resources. A disaster is triggered by a natural or...
  18. The organization and management of resources and responsibilities to address response and recovery. This definition implies that disaster management comprises those activities conducted once a disaster has taken place and excludes those activities...
  19. The complete set of phases related to disasters and their management (prevention, mitigation, preparedness, response, rehabilitation, reconstruction and recovery). The mission statement of UN-SPIDER makes reference to the provision of universal...
  20. The potential disaster losses, in lives, health status, livelihoods, assets and services, which could occur to a particular community or a society over some specified future time period. Disaster Risk is represented through the combination of hazard...
  21. Disaster risk management aims to avoid, lessen or transfer the adverse effects of hazards through prevention, mitigation and preparedness. This definition would imply that disaster risk management comprises activities conducted before the disaster...
  22. The set of all measures carried out in the disaster management cycle, but making explicit reference to those conducted before and after the disaster. It is important to recognize that different agencies work in disaster risk management and in...
  23. The set of agencies, organizations and institutions at local, national, regional and international levels that focus their activities on prevention, mitigation and preparedness.
  24. Performed in twenty-four hours, such as the diurnal rotation of the Earth. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  25. DLR
    German Aerospace Center
  26. Disaster Monitoring Constellation International Imaging
  27. The standard way to express ozone amounts in the atmosphere. One DU is 2.7 x 10 exp 16 (10 to the 16th power) ozone molecules per square centimeter. One Dobson unit refers to a layer of ozone that would be 0.001 cm thick under conditions of standard...
  28. The apparent change in frequency of sound or light waves, varying with the relative velocity of the source and the observer. If the source and observer draw closer together, the frequency is increased. Named for Christian Doppler, Austrian...
  29. The weather radar system that uses the Doppler shift of radio waves to detect air motion that can result in tornadoes and precipitation, as previously-developed weather radar systems do. It can also measure the speed and direction of rain and ice,...