Scientific or technical measurements, values calculated therefrom, observations, or facts that can be represented by numbers, tables, graphs, models, text, or symbols which are used as a basis for reasoning and further calculation.

For NASA's Earth Science Program and according to NASA's Earth Science Data & Information Policy, the term 'data' includes observation data, metadata, products, information, algorithms, including scientific source code, documentation, models, images, and research results.

Data assimilation is defined as the process of combining observations with model simulations to enhance the accuracy of predictions.

A major release of a data product, or of a set of closely related data products, which can be followed by minor releases within the same collection.

See also: Data Set Series on this page.

An entity responsible for archiving and distributing data products. 

See also: DAAC.

A standard way that information is encoded for storage in a computer file (see more about data formats). An example is HDF5.

Data Format Control Documents (DFCDs), and other data format documents (e.g., Data Format Requirements Documents (DFRDs)), define the formats of data units that are transferred across an interface and the control codes used in the data formats.

As defined for an OAIS entity that contains the services and functions for populating, maintaining, and accessing a wide variety of information. Some examples of this information are catalogs and inventories on what may be retrieved from Archival Storage, processing algorithms that may be run on retrieved data, Consumer access statistics, Consumer billing, Event Based Orders, security controls, and OAIS schedules, policies, and procedures.

Beta
Products intended to enable users to gain familiarity with the parameters and the data formats. 

Provisional
Product was defined to facilitate data exploration and process studies that do not require rigorous validation. These data are partially validated and improvements are continuing; quality may not be optimal since validation and quality assurance are ongoing. 

Validated
Products are high quality data that have been fully validated and quality checked, and that are deemed suitable for systematic studies such as climate change, as well as for shorter term, process studies.

Stage 1 Validation: Product accuracy is estimated using a small number of independent measurements obtained from selected locations and time periods and ground-truth/field program efforts. 

Stage 2 Validation: Product accuracy is estimated over a significant set of locations and time periods by comparison with reference in situ or other suitable reference data.

Stage 3 Validation: Product accuracy has been assessed. Uncertainties in the product and its associated structure are well quantified from comparison with reference in situ or other suitable reference data.

Stage 4 Validation: Validation results for stage 3 are systematically updated when new product versions are released and as the time-series expands.

An Earth science metadata model, which supports the data standardization necessary for total system interoperability within a heterogeneous, open systems environment. The Data Model includes diagrams, which graphically illustrate the relationships of classes, the attributes contained within the classes, the characteristics of the relationships between classes, and the attribute specifications.

The level of processing that results in data products ranging from raw instrument data to refined analyses that use inputs from various sources. See also: Data Maturity Levels.

A person or group that directly collects/creates data to be submitted to a NASA DAAC for archiving and public distribution.

A set of data files that can contain multiple parameters and that compose a logically meaningful group of related data.

See: Quality Indicator

NASA ESDIS processes, archives, documents, and distributes data from NASA's past and current Earth-observing satellites and field measurement programs. Each DAAC serves a specific Earth system science discipline and provides users with data products, services, and data-handling tools unique to the center's specialty. User services include:

• Assistance in selecting and obtaining data
• Access to data-handling and visualization tools
• Technical support and referrals

Information describing the characteristics of a data set and its component granules, including format, source instrumentation, calibration, processing, algorithms, etc.

1. A logically meaningful grouping or collection of similar or related data. Data having all of the same characteristics (source or class of source, processing level, resolution, etc.) but different independent variable ranges and/or responding to a specific need are normally considered part of a single data set. A data set is typically composed by products from several missions, gathered together to respond to the overall coverage or revisit requirements from a specific group of users. In the context of EO data preservation, a data set consists of the data records and their associated knowledge (information, tools).
    
2. A broadly used term that can be used to describe any set of data. The official term “HDF5 dataset” describes a data array in an HDF5 file (equivalent to a NetCDF-4 variable in a NetCDF-4 file or an HDF-EOS field in an HDF-EOS file). An entire data collection is sometimes referred to as a dataset.

A major release of a data product, or of a set of closely related data products, which can be followed by minor releases within the same collection.

In Earth Science data products, a multi-dimensional container for geolocation and science data tailored for a specific type of instrument acquisition mode or spatial arrangement of the data (e.g., swath, grid, zonal mean, trajectory)

A document, either on-line or hardcopy, containing the necessary information for the correct usage of the data.

See: Visualization

DRs evaluate the readiness of the program and its projects to conduct closeout activities, including final delivery of all remaining program/project deliverables and safe decommissioning/disposal of space flight systems and other program/project assets.

Derived products are higher level products (level 1b through 4) where calibration and geo-location transformations have been applied to generate sensor units, and/or algorithms have been applied to generate gridded geophysical parameters.

DMRs include Mission-Specific Requirements Documents (MSRDs) and mission requirement documents (e.g., Ground System Requirements Documents (GSRDs), and Mission Operations Requirements Documents (MORDs)). DMRs contain the results of the requirements identification and derivation activities and provide the basis for system design for individual missions.

A field of study such as oceanography, meteorology, geology, or marine biology.

Successful identification and location of data products of interest. 

Any service that helps the user to identify and locate EO resource starting from his needs. 

See also: Search and Discovery.

DRRs evaluate the readiness of the project and the flight system for execution of the spacecraft disposal event.

EOSDIS is designed as a distributed system, with major facilities at Distributed Active Archive Centers (DAACs) located throughout the United States. These institutions are custodians of EOS mission data and ensure that data will be easily accessible to users. EOSDIS DAACs process, archive, document, and distribute data from NASA's past and current Earth-observing satellites and field measurement programs. Acting in concert, DAACs provide reliable, robust services to users whose needs may cross the traditional boundaries of a science discipline, while continuing to support the particular needs of users within the discipline communities. User services include:

• Assistance in selecting and obtaining data
• Access to data-handling and visualization tools
• Technical support and referrals

The allocation of ESDIS elements to various locations to take best advantage of each location's different institutional capabilities and science expertise.