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EOS - Astronomy Glossary
Category: Earth and Environment > meteorology and astronomy
Date & country: 13/09/2007, USA
Words: 196

Hard Metric
The use of rational metric units as the basis of measurement rather than mathematically converted inch-pound units.

In-Situ Data
Data associated with reference to measurements made at the actual location of the object or material measured, by contrast with remote sensing (i.e., from space).

Information Management System (Ims)
The user interface for EOSDIS. It provides information about data, both in EOSDIS and in external archives, on a 24-hour basis; accepts user orders for EOS data; provides information about future data acquisition and processing schedules; accepts and forwards data acquisition and processing requests; and maintains information on system status, management, and coordination.

Infrared Radiation
Electromagnetic radiation lying in the wavelength interval from 0.7 5m to 1000 5m (micrometers). Its lower limit is bounded by visible radiation, and its upper limit by microwave radiation. Most of the energy emitted by the Earth and its atmosphere is at infrared wavelengths. Infrared radiation is generated almost entirely by large-scale intramolecular processes. The tri-atomic gases, such as water vapor, carbon dioxide, and ozone, absorb infrared radiation and play important roles in the propag…

An integrated collection of hardware containing one or more sensors and associated controls designed to produce data on an environment.

Instrument Control Center (Icc)
An EOS facility dedicated to a specific instrument that plans and schedules instrument operations, generates and validates command sequences, provides the capability to forward commands and to store them for later transmission, monitors the health and safety of the instrument, and provides instrument controllers with status information of their instrument.

Instrument Control Facility (Icf)
A facility containing one or more EOS ICCs.

Instrument Data
Data specically associated with the instrument, either because they were generated by the instrument or included in data packets identifed with that instrument. These data consist of instrument science and engineering data, and possible ancillary data.

Instrument Engineering Data
Data produced by the engineering sensor(s) of an instrument that is used to determine the physical state of an instrument in order to operate it, monitor its health, or aid in processing its science data.

Instrument Science Data
Data produced by the science sensor(s) containing the primary observables of an instrument, usually constituting the mission of that instrument.

Interdisciplineary Scitentist
An individual selected by the project and/or the peer review process who is responsible for conducting investigations requiring analysis, interpretation, and use of data which crosses instrument and discipline boundaries.

International Partners
Signatories of the Space Station MOUs that established the initial funding for the International Polar Platforms program to monitor Global Change, including NASA, ESA, Japan, and Canada.

A uniform set of descriptions of granules from one or more data sets with information required to select and obtain a subset of those granules. Granule descriptions typically include temporal and spatial coverage, data quality indicators, and physical storage information. An inventory may describe physical granules, logical granules, or both, including a mapping between them if they are not identical.

Inventory Service
An inventory, possibly supplemented with other kinds of information, combined with a mechanism to provide responses to queries, possibly including ordering data.

Inventory System
A specific implementation of an inventory service.

Rarefied, ionized region of the Earth's atmosphere, between approximately 60 and 400 km.


Logical Granule
The smallest aggregation of data which is independently identified (i.e., described, inventoried).

Logical Record
A collection of data whose location and extent are defined in terms of the information it contains and not in terms related to the physical medium on which it is stored. Portions of the same logical record may be located in different physical records, or several logical records may be located in one physical record.

Logical Volume
That portion of a volume which is viewed by a computer operating system as a complete collection of available files. For instance, with today's WORM optical disk drives, each side of a two-sided disk is a logical volume.

Layer of the Earths interior between the core and crust, ranging from depths of approximately 2900 km-40 km.

Measurement Mode Duty Cycle
The fraction of available time during which an instrument is actively performing Earth measurements and producing meaningful data, including incidental calibration and overhead (such as scan retrace). High data rate, high power consumption, and steerable instruments may have small duty cycles. Daylight-only instruments may have measurement mode duty cycles averaging 50 percent.

Region of the atmosphere between approximately 50 and 85 km.

The structured component in the mechanism for communicating information between an IMS client and archive databases. Different types of messages, corresponding to the functional subsystem of the IMS, are exchanged through the client/server architecture. Message types include, for example, inventory search and inventory result.

(1) Information about a data set which is provided by the data supplier or the generating algorithm and which provides a description of the content, format, and utility of the data set. Metadata provide criteria which may be used to select data for a particular scientific investigation. (2) Information describing a data set, including data user guide, descriptions of the data set in directories, and inventories, and any additional information required to define the relationships among these.

An investigative technique that uses a mathematical or physical representation of a system or theory that accounts for all or some of its known properties. Models are often used to test the effects of changes of system components on the overall performance of the system.

Direction toward the center of the Earth. Opposite of zenith.

Near Real-Time Data
Data from the source that are available for use within a time that is short in comparison to important time scales in the phenomena being studied.

Near-line refers to tapes or other archive media that are typically stored for very quick access and loading on the computer system for use (i.e. robotic tape silos or optical disc jukeboxes). Source: EDC/ESDIS.

Negative Feedback
An interaction that reduces or dampens the response of the system in which it is incorporated.

Network Manager
A body of software modules that receive, interpret, and transmit, (depending on a particular state), an appropriate message to the archive server and the user interface software subsystems.

Any substance assimilated by living things that promotes growth.

Ocean Mixing
Processes that involve rates of advection, upwelling/downwelling, and eddy diffusion and that determine, for example, how rapidly excess atmospheric carbon dioxide can be taken up by the oceans.

Access to information by mail, telephone, facsimile, or other non- direct interface.

Access to information by direct interface to an information data base via electronic networking.

Operational Facility Instrument
An instrument developed and operated by a national or international agency (e.g., NOAA, DOD) to support their operational requirements. Data from such an instrument may be made available to the research community.

Within EOSDIS, those activities di-rectly related to the acquisition, archiving, distribution, and processing of mission-related information.

Orbit Data
Data that represent spacecraft locations. Orbit (or ephemeris) data include: Geodetic latitude, longitude and height above an adopted reference ellipsoid (or distance from the center of mass of the Earth); a corresponding statement about the accuracy of the position and the corresponding time of the position (including the time system); some accuracy requirements may be hundreds of meters while other may be a few centimeters.

A molecule made up of three atoms of oxygen. In the stratosphere, it occurs naturally and provides a protective layer shielding the Earth from ultraviolet radiation and subsequent harmful health effects on humans and the environment. In the troposphere, it is a chemical oxidant and major component of photochemical smog. Ozone is an effective greenhouse gas especially in the middle and upper troposphere and lower stratosphere.

A set of data granules organized for distribution by a DAAC. Source: ESDIS IMS Lexicon.

A measurable or derived variable representedby the data (e.g. air temperature, snow depth, relative humidity.

Pathfinder Data Set
A long-term, global Earth science data set produced from non-EOS data using community consensus algorithms as part of the EOSDIS Program. Selection of Pathfinder Data Sets is made by the EOS Program Office (in consultation with the IWG and the science community).

The complement of instruments that are accommodated on a spacecraft.

The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll with sunlight as the energy source. Oxygen and water vapor are released in the process. Photosynthesis is dependent on favorable temperature and moisture conditions as well as on the atmospheric carbon dioxide concentration. Increased levels of carbon dioxide can increase net photosynthesis in many plants.

Physical Granule
The smallest aggregation of data which is independently accessible (i.e., located, readable, reproducible) on physical media.

Physical Medium
Any physical material capable of holding data (e.g., pages, film, magnetic tape, optical disk, wire, silicon).

Physical Record
A collection of data whose location and extent are defined in terms related to the physical medium on which it is stored. A physical record may contain one or several logical records or a part of a logical record.

That portion of the plankton community in a body of water made up of tiny plants (e.g., algae and diatoms).

Planetary Albedo
The fraction of incident solar radiation that is reflected by a planet and returned to space. The planetary albedo of the Earth-atmosphere system is approximately 30 percent, most of which is due to backscatter from clouds in the atmosphere.

Playback Data
Data that are stored on a spacecraft, platform, or other carrier that are transmitted at a later time.

Positive Feedback
An interaction that increases or amplifies the response of the system in which it is incorporated.

Primary Productivity
The rate of carbon fixation by marine photosynthetic organisms (phytoplankton). Primary productivity results in the reduction of dissolved inorganic carbon to form organic carbon, with concomitant release of oxygen.

Principal Investigator (Pi)
The individual selected by proposal review, who has primary responsibility for preparing the proposal, selecting the investigation team, carrying out the scientific investigation, and reporting the results. Responsibilities often include supplying an instrument.

Principal Investigator Instrument
An instrument developed and managed by a Principal Investigator (PI) selected through the NASA, or equivalent, Announcement of Opportunity (AO) process.

Processing Level
IMS interface term. See Data Product Level.

Product Generation System (Pgs).
An EOS DAAC element that performs data processing functions, including routine generation of Standard Data Products, routine generation of associated quick-look products, metadata, and browse data sets, reprocessing of data, and retrospective generation of new Standard Data Products. In practice, a PGS should consist of the hardware and application software at a DAAC used for generating data products. The PGS at a DAAC may also provide computational support for research and special product tria…

Product Request
Within the IMS interface a request is an action initiated by a user to order data from a DAAC.

Prototype Data Products

Prototype Instrument
An instrument primarily intended as a prototype for developing an operational instrument capability. The instrument may be replaced by an operational model, or declared operational after the functional utility of the instrument is understood.

Quick-Look Data
Data available for examination within a short time of receipt, where completeness of processing is sacrificed to achieve rapid availability.

Raw Data
Data in their original packets, as received from the observer, unprocessed by EDOS.

Raw Data
Numerical values representing the direct observations output by a measuring instrument transmitted as a bit stream in the order they were obtained. Also see DATA PRODUCT LEVEL.

Real-Time Data
Data that are acquired and transmitted immediately to the ground (as opposed to playback data). Delay is limited to the actual time (propagation delays) required to transmit the data.

Research Facility Instrument
An instrument provided and managed by an institution for use by a group of approved investigators. Data from the instrument may be made available for the operational applications.

That amount of a resource held by the EOS Program and Project to satisfy unanticipated requirements or objectives.

Information generated and communicated from the archive (DAAC) to the IMS client and displayed in the user interface as a result of a user-initiated search.

Results Integration
The mechanism in the IMS client that merges, manages, and presents to the interface result messages received from the archives (DAACs).

Return Link Data
Spacecraft health and status data and instrument data.

Science Computing Facility (Scf)
A facility supplied by the EOS Program to an EOS TL, TM, or PI (Instrument or Interdisciplinary) for the following purposes: developing and maintaining the algorithms and software used to generate Standard Data Products; quality control of Standard Data Products; in-flight instrument calibration and data set validation; scientific analysis, modeling, and research; generation of Special Data Products; and use as an interface to the investigatorUs institutional facility.

Within the IMS interface search is the action of composing a set of criteria for locating information. These criteria are communicated to the DAACs in a search message structure where it is processed, through DAAC mapping layers, into local database queries.

A device which transmits an output signal in response to a physical input stimulus (as radiance, sound, etc.). Science and engineering sensors are distinguished according to the stimuli to which they respond.

Signal-To-Noise Ratio (S-N)
The ratio of the level of the information-bearing signal power to the level of the noise power. For MODIS, the ratio between (1) typical cloud free scene brightness with solar zenith angle Z=70 deg, and (2) all sensor and processing noise contributions. S/N specifications for various scenes (e.g., land, clouds, oceans, ice) are only applicable in the filter bands associated with those scenes.

The observational environment, entity or structure which holds the data collection device (usually an instrument). It may be a satellite, aircraft, ground station, buoy, ship, person (in the case of human observations or hand-held instruments), computer (in the case of computer model data), or a questionaire (in the case of a paper survey (e.g. CIESIN's Census data).

Space Network (Sn)
The NASA assets required to communicate with Earth-orbiting spacecraft via the TDRSS.

The spacecraft is the EOS space or orbiting component composed of the payload and mission-unique equipment required to support the EOS mission. It includes propulsion, separation springs, and user interface equipment not unique to the launch vehicle.

Spacecraft Engineering Data
Data produced by the engineering sensor(s) of a spacecraft that are used to determine the physical state of the spacecraft, in order to operate it or monitor its health.

Special Data Product
A data product produced at a Science Computing Facility by a research status algorithm. May migrate to a community consesus algorithm at a latter point. If adequate community interest, may be archived and distibuted by a DAAC. Source: ESDIS.

Special Data Products

Standard Data Product
A data product produced at a DAAC by a community concensus algorithm. Typically produced for a wide community. May be produced routinely or on-demand. If produced routinely, typically produced over most or all of the available independent variable space. If produced on-demand, produced only on request from users for particular research needs typically over a limited range of independent variable space.

Standard Data Products

Static Browse
Refers to interrogation of browse products which have been generated (through subsetting and/or resampling) before any user browses that particular data set.

Region of the atmosphere between the troposphere and mesosphere, having a lower boundary of approximately 8 km at the poles to 18 km at the equator and an upper boundary of approximately 50 km. Depending upon latitude and season, the temperature in the lower stratosphere can increase, be isothermal, or even decrease with altitude, but the temperature in the upper stratosphere generally increases with height due to absorption of solar radiation by ozone.

Support Equipment
Equipment used to interface with the spacecraft for the purpose of simulating the command and telemetry interface which will be present in the EOC, as well as providing additional status information that may be nec-essary in the integration and verification processes.

Team Leader (Tl)
The person designated by the EOS Program as ultimately responsible for the delivery and performance of Standard Data Products derived from an EOS Facility Instrument.

Team Member (Tm)
A person designated by the EOS Program to develop algorithms for Standard Data Products derived from an EOS Facility Instrument.

A space-to-ground data stream of measured values (including instrument science data, instrument engineering data, and spacecraft engineering data) that does not include command, tracking, computer memory transfer, audio, or video signals.

Outermost layer of the atmosphere, above the mesosphere.

Trace Gas
A minor constituent of the atmosphere. The most important trace gases contributing to the greenhouse effect are water vapor, carbon di-oxide, ozone, methane, nitrous oxide, and chloro-fluorocarbons. Other trace gases include ammonia, nitric oxide, ethylene, sulfur dioxide, methyl chloride, carbon monoxide, and carbon tetrachloride.

Boundary between the upper troposphere and the lower stratosphere that varies in altitude between approximately 8 km at the poles to 18 km at the equator.

Lowest atmospheric layer, between the surface and tropopause.

The vertical motion of water in the ocean by which subsurface water of lower temperature and greater density moves toward the surface of the ocean. Upwelling occurs most commonly along the western coastlines of continents, but may occur anywhere in the ocean. Upwelling results when winds blowing nearly parallel to a continental coastline transport the light surface water away from the coast. Subsurface water of greater density and lower temperature replaces the surface water, and exerts a consid…

Any person accessing the EOSDIS. AUTHORIZED USERS are users who have viable EOSDIS accounts, and who may therefore make EOSDIS data requests. These users may be Affiliated or Unaffiliated. AFFILIATED USERS are those who are sponsored by one of the parties to the Earth Observations ICWG (EO-ICWG) data policy. Each party is responsible for ensuring that all its affiliated users comply with the EO-ICWG data policy.

A value of a particular attribute (or column in a database). Valids (or keywords in the IMS interface) are both the search criteria and the key descriptions of attributes for inventory information. For example, 'radiance' is a keyword within the attribute domain Parameter.

The set of values (often keywords) identified for specific categories (i.e. parameter, source, etc.) used to form valid search criteria used in the v.0 IMS interface.

Visual Aids
Any graphical representation of data used to communicate the contents or meaning (including spatial and temporal location) of the data.

A unit of physical media which contains data, usually physically interchangeable with other volumes of a similar type, and requiring a specific device for reading or writing (e.g., a CD-ROM).