European Facility For Airborne Research July 5, 2022, 00:22
aberration: Spatial error of projecting an object at the surface of the earth.
absorption: The process by which electromagnetic radiation is assimilated and converted into other forms of energy, primarily heat. Absorption takes place only on the electromagnetic radiation that enters a medium, and not on electromagnetic radiation incident on the medium but reflected at its surface.
absorption band: A range of wavelengths (or frequencies) of electromagnetic radiation that is assimilated by a substance.
ACCENT Plus: Atmospheric Composition Change The European NeTwork. The general concept for ACCENT-Plus is to extend the breadth of ACCENT to reach out more strongly to the policy community to facilitate the transfer of research results into policy development and decision making.
ACTRIS: Aerosols, Clouds, and Trace gases Research InfraStructure. The ACTRIS-2 Integrating Activities (IA) addresses the scope of integrating state-of-the-art European ground-based stations for long-term observations of aerosols, clouds and short lived gases. It consolidates and improves services offered within FP7 funded Integrated Infrastructures Initiative ACTRIS (2011-2015). ACTRIS-2 takes up the overarching objectives of ACTRIS to further integrate the European ground-based stations and to construct a user-oriented RI, unique in the EU-RI landscape, for aerosols, clouds, and short-lived gas-phase species.
adjacency effect: Influence of adjacency radiation (atmospheric and volume backscattering) to the total radiance signal.
aerosol: The term is used to describe many types of small particles in the atmosphere that both absorb and reflect incoming sunlight.
albedo: The ratio of the amount of electromagnetic energy reflected by a surface to the amount of energy incident upon it.
aperture: An opening that admits electromagnetic radiation to a film or detector. An example would be the lens diaphragm opening in a camera.
atmospheric correction: The correction made to remotely sensed radiance to reduce or normalize for the intervening atmosphere between the surface of the earth and the sensor.
atmospheric window: The range of wavelength of the electromagnetic spectrum at which the atmosphere and atmospherically gases respectively only slightly absorbs radiation.
at-sensor radiance: Radiance at the entrance aperture of an optical instrument.
altitude: Height above a datum, the datum usually being mean sea level.
attitude: Angular orientation of the sensor system (see also roll, pitch, yaw).
attribute: A descriptive parameter attached to a data variable e.g. units, valid range, etc
auxiliary data (aux): Data required to perform processing of sensor data which is not obtained from the sensor itself.
azimuth: The arc of the horizon measured clockwise from true north to the point referenced expressed in degrees.