Skip to main content

Glossary of Terms

Reference the Earth Observation Data Basics Glossary to better understand terms related to the data provided by our program.

All
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Description Source
Earth Observing System Data and Information System (EOSDIS)

NASA's Earth Observing System Data and Information System (EOSDIS) is a key core capability in the Earth Science Data Systems (ESDS) Program. It provides end-to-end capabilities for managing NASA Earth science data from various sources—satellites, aircraft, field measurements, and various other programs. For the EOS satellite missions, EOSDIS provides capabilities for command and control, scheduling, data capture and initial (level 0) processing. These capabilities, constituting the EOSDIS Mission Operations, are managed by NASA's Earth Science Mission Operations (ESMO) Project. 

The remaining capabilities of EOSDIS constitute the EOSDIS Science Operations, which are managed by NASA's Earth Science Data and Information System (ESDIS) Project. These capabilities include: generation of higher level (levels 1-4) science data products for EOS missions; and archiving and distribution of data products from EOS and other satellite missions, as well as aircraft and field measurement campaigns. The EOSDIS science operations are performed within a distributed system which includes Science Investigator-led Processing Systems (SIPS) and distributed, discipline-specific, Earth science Distributed Active Archive Centers (DAACs). 

See: EOSDIS

Earth Science Data and Information System (ESDIS) Project

NASA's Earth Science Data and Information System (ESDIS) Project is a part of NASA's Earth Science Projects Division under the Flight Projects Directorate at NASA's Goddard Space Flight Center. ESDIS manages the science systems of NASA's Earth Observing System Data and Information System (EOSDIS). 

See Earth Observing System Data and Information System (EOSDIS)

See: ESDIS

Earth Science Data Type (ESDT)

Each type of science data collected by an instrument aboard a satellite supported by the ECS is given a data type name to be stored or archived in the ECS inventory (e.g., MISR001.) ESDTs also define the Services which can be applied to the data and the metadata associated with the data. In addition, ESDTs are defined for all data referenced in the ECS inventory and this includes some non-satellite data, and some non-instrument data (e.g., science software archive packages, algorithm packages, pge tar files, and delivered algorithm packages).

Earth Science Mission Operations (ESMO)

NASA's Earth Science Mission Operations (ESMO) Project is responsible for spacecraft maintenance and operations for Earth Science missions conducted by NASA's Earth Science Projects Division at NASA's Goddard Space Flight Center. ESMO plays a significant role during the mission life cycle; from the formulation and approval phases through the implementation and evaluation phases, and eventual deactivation. 

The Project's role is to ensure the health and safety of the missions it manages by fulfilling the primary operational requirements for each mission, and providing the scientific community with high-quality data products in a timely manner. It also serves as a focal point for the mission on-orbit operations and the definition of support services required.

See: ESMO

Engineering Data

Data which describe the physical condition and operation of the platform and instruments on the platform. Parameters might include temperatures at specific points, filter(s) in use, switch settings, memory data, etc.

Definition from EO Data Stewardship Glossary

EOS Data and Information System (EOSDIS) Core System (ECS)

The infrastructure which provides NASA's Earth Observing System (EOS) and other U.S. and international scientists a broad range of desktop services from NASA's discipline-specific Distributed Active Archive Centers (DAACs). The ECS infrastructure also supports exchange of data and research results within the science community, across multiple agencies and internationally. ECS is the evolutionary base for accelerating the pace of Earth science research.

See: EOSDIS

File Format

A term that is used for both "Data Format" and "Product Format" whose meaning should be understood by its context. 

See: Data Format

See: Data Product Developers Guide for Data Producers

Flight Readiness Review (FRR)

FRRs evaluate the readiness of the program and its projects, ground systems, personnel, and procedures for a safe and successful launch and flight/mission.

See: Data System Interfaces

Footprint

Geographic area covered by an instrument's observation and its derived products.

Definition from EO Data Stewardship Glossary

Formulation Agreement (FA)

The FA is prepared by the project to establish the technical and acquisition work that needs to be conducted during formulation and defines the schedule and funding requirements during Phase A and Phase B for that work.

See: Data System Interfaces

Formulation Authorization Document (FAD)

The FAD is issued by the Mission Directorate Associate Administrator (MDAA) to authorize the formulation of a program whose goals will fulfill part of the Agency's Strategic Plan and Mission Directorate strategies and establish the expectations and constraints for activity in the Formulation Phase. In addition, a FAD or equivalent is used to authorize the formulation of a project. (See Appendix E.)

See: Data System Interfaces

Forward Processing

A term used in data processing when the data is moving from one version to another version.

Global Attribute

An attribute that applies to either the entire file or the entire collection of files.

See: Data Product Developers Guide for Data Producers

Global Imagery Browse Services (GIBS)

GIBS provides full resolution visual representations of NASA Earth science data in a free, open, and interoperable manner.

See: GIBS APIs

Granule
  1. The smallest aggregation of data which is independently managed (i. e. described, inventoried, retrievable). Granules may be managed as logical granules and/or physical granules. 

    See also: Scene 
     
  2. The smallest aggregation of independently managed (i.e., described, inventoried, retrievable) data at a DAAC. Some web applications and services provided by DAACs allow for the subsetting of granules. One granule usually comprises one file, more rarely multiple files. The latter is not optimal as it complicates data management by both the archive and users, and utilization by tools and services.

Definition 1 from EO Data Stewardship Glossary

Definition 2 from Data Product Developers Guide for Data Producers

Granule Metadata

These are metadata elements that describe a single granule of a data product. Values of granule metadata apply to all of the data in that one granule. Typical metadata in this category describe spatial and temporal extent of the data as well as the quality and lineage of the data. 

See also: Granule.

Hierarchical Data Format (HDF)

The Hierarchical Data Format (HDF) is designed to facilitate managing and sharing scientific data. HDF includes two formats (HDF4 and HDF5), software for accessing data in HDF formats, and applications for working with HDF data. 

HDF is designed for efficient storage and access of high volume, complex data, and for mixing varieties of data types in a single container.

See: Data Formats

Ingestion

The ingestion function accepts data from different sources: ground segment reception, processing or data migration elements. The received data is quality checked and metadata including browse images are obtained from the data. The data and metadata form a data product. The product is consistently submitted to archiving and cataloguing.

Definition from EO Data Stewardship Glossary

Instrument Calibration

The instrument calibration function is the determination of parameters describing instrument characteristics. They are to be used by the instruments and ground processing to generate calibrated and comparable physical values. These parameters vary for different instruments and modes. And they may vary over time in the long run (degradation).

Definition from EO Data Stewardship Glossary

Inter-Project Agreement (IPA)

IPAs are agreements between ESDIS and projects not managed by ESDIS. Generally, the projects involved agree on an exchange of support services and data. From the interface control viewpoint, these agreements identify the need for an interface and the scope of the interface.

See: Data System Interfaces

Interface Control Documents (ICD)

ICDs are used to record design agreements for the interfaces between participating organizations. ICDs provide a means to evaluate and control all mutually interdependent and/or interacting design parameters of the interface.

See: Data System Interfaces

Interface Requirement Documents (IRD)

IRDs define the requirements for data exchanges across an interface between separately managed systems or subsystems. The requirements statements in IRDs are derived directly from project requirements documents.

See: Data System Interfaces

Interoperability

The ability of different information technology systems and software applications to communicate, exchange data, and use the information that has been exchanged. 

In Earth observation it includes e.g. interoperable discovery and access, i.e. the capability of the user interface and administrative software of one instance of a catalogue service to interact with other instances of catalogue services. E.g. the capability of accessing granules in one data format with APIs or services of another API.

Definition from EO Data Stewardship Glossary

Inventory

The inventory function provides organization capabilities for archiving management. Data products can be grouped, searched and identified for retrieval, statistics and reorganization. Inventory is also referred to the list of available items stored and/or controlled in a storage warehouse system. 

In this latter case it is necessary to specify the kind of inventory, e.g. ICT Inventory for infrastructure inventory list.

Definition from EO Data Stewardship Glossary

Key Decision Point (KDP)

A key decision point (KDP) is the event at which the Decision Authority determines the readiness of a program/project to progress to the next phase of the life cycle (or to the next KDP).

See: Data System Interfaces

Launch Readiness Review (LRR)

LRRs evaluate a program/project and its ground, hardware, and software systems for readiness for launch.

See: Data System Interfaces

Launch Vehicle (LV)

LVs are rockets that send people and other payloads into space.

See: Data System Interfaces

Long Term Preservation

The act of maintaining information in a correct and independently understandable form over the long term, i.e. a period of time long enough to be concerned with the impact which changing technologies, including support for media and data formats, and changing user communities will have on the information being held in a repository. 

See: Preservation.

Definition from EO Data Stewardship Glossary

Metadata

Data about data, contained in data sets, and which provides an understanding of the content and utility of the data set. Metadata may be used to select on data for a particular scientific investigation. 

Metadata is intended as information describing significant aspects of a resource (Earth Observation space data in this context). They are created for the purposes of data search, discovery and access management and may exist at various levels, typically from data collection through to the individual variables of each data file in a collection.

Definition from EO Data Stewardship Glossary

Mission Concept Review (MCR)

MCRs evaluate the feasibility of the proposed mission concept(s) and its fulfillment of the program's needs and objectives. MCRs also determine whether the maturity of the concept and associated planning are sufficient to begin Phase A.

See: Data System Interfaces

Mission Definition Review (MDR)

MDRs evaluate the credibility and responsiveness of the proposed mission/system architecture to the program requirements and constraints, including available resources. MDRs also determine whether the maturity of the project's mission/system definition and associated plans are sufficient to begin Phase B.

See: Data System Interfaces

Mission Readiness Review (MRR)

MRRs evaluate the readiness of the program and its projects, ground systems, personnel, and procedures for a safe and successful launch and flight/mission.

See: Data System Interfaces

Mission Readiness Test Plan (MRTP)

The MRTP documents the strategy that will be used to verify and ensure that all system components working together meet design specifications and requirements for the mission.

See: Data System Interfaces

Modeling

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.

Mosaic

A composite of two or more images put together to create one image.

NASA-compliant General Application Platform (NGAP)

NGAP provides a NASA-compliant, secure, cloud-based Platform-as-a-Service (PaaS) and Infrastructure-as-a-Service (IaaS) for hosting Earth Observing System Data and Information System (EOSDIS) applications.

Definition from the Definition from the EOSDIS Engineering and Design (EED) contract team contract team

Near Real-Time (NRT) Data

NRT Data are those that are available for use with a specified (small and application dependent) latency, which is typically 3 hours for meteorological applications. See LANCE.

Definition from EO Data Stewardship Glossary

NetCDF-4/HDF5

NetCDF format that uses the HDF5 data storage model.

See: Data Product Developers Guide for Data Producers

On-Demand Data Set

Collection of products that are generated in response to a user's request. Such products could either be pre-defined or not.

Definition from EO Data Stewardship Glossary

Operational Readiness Review (ORR)

ORRs evaluate the readiness of the program, including its projects, ground systems, personnel, procedures, and user documentation. ORRs also operate the flight system and associated ground systems in compliance with program requirements and constraints during the operations phase.

See: Data System Interfaces

Operations Agreement (OA)

Operations Agreements are even lower level, more detailed interface documents that are created to help define the operations use of the interfaces, including such things as addresses, phone numbers, and names of responsible personnel. These documents are not intended for project-level development and control.

See: Data System Interfaces

Parameter (or Variable)

A measurable or derived variable occurring in the physical or digital world. Variable and Parameter are used interchangeably. GCMD uses the term variable and NSIDC DAAC uses the term parameter.

Definition from EO Data Stewardship Glossary

Post-Flight Assessment Review (PFAR)

PFARs evaluate how well mission objectives were met during a human space flight mission. PFARs also evaluate the status of the flight and ground systems, including the identification of any anomalies and their resolution.

See: Data System Interfaces

Post-Launch Assessment Review (PLAR)

PLARs evaluate the in-flight performance of the program and its projects. PLARs also determine the program's readiness to begin the operations phase of the life cycle and transfer responsibility to the operations organization.

See: Data System Interfaces

Preliminary Design Review (PDR)

PDRs evaluate the completeness/consistency of the program's preliminary design, including its projects, in meeting all requirements with appropriate margins, acceptable risk, and within cost and schedule constraints, and to determine the program's readiness to proceed with the detailed design phase of the program.

See: Data System Interfaces

Preservation

Preservation covers all processes and operations on individual or multi-mission data sets for ensuring the technical and intellectual survival of space data sets and their metadata through time. It grants dataset integrity, its discoverability and accessibility, and facilitates its use and reuse in the long term. 

Preservation is one of the tasks of data curation. Examples are data record improvement and consolidation.

Definition from EO Data Stewardship Glossary

Processing

The processing function generates higher-level products from lower level products and auxiliary products. The processing is performed by core algorithms supplemented by administrative functions (e.g. formatting). The algorithms are version controlled. Processing is able to produce the desired products systematically or on request.

Definition from EO Data Stewardship Glossary

Processing Levels

Raw Data 
The physical telemetry payload data as received from the satellite, i.e. a serial data stream without de-multiplexing. 

Level 0 
Reconstructed unprocessed data at full space-time resolution with all available supplemental information to be used in subsequent processing (e.g. ephemeris, health and safety) appended. 

Level 1A 
Reconstructed unprocessed data at full resolution, time-referenced, and annotated with ancillary information, including radiometric and geometric calibration coefficients and geo-referencing parameters (e.g. ephemeris) computed and appended but not applied to the Level 0 data. 

Level 1B 
Radiometrically corrected and calibrated data in physical units at full instrument resolution as acquired. Level 1C L1B data orthorectified, re-sampled to a specified grid 

Level 2 
Derived geophysical parameters (e.g. sea surface temperature, leaf area index) at the same resolution and location as Level 1 source data. 

Level 3 
Data or retrieved geophysical parameters which have been spatially and/or temporally re-sampled (i.e. derived from Level 1 or 2 products), usually with some completeness and consistency. Such re-sampling may include averaging and compositing. 

Level 4 
Model output or results from analyses of lower level data (i.e., variables that are not directly measured by the instruments, but are derived from these measurements; could be derived from multiple instrument measurements).

Definition from EO Data Stewardship Glossary

Product

1.
Electronic data package distributable to users; content is derived from instrument data via processing involving ancillary and auxiliary data. Products may comprise metadata and browse images. 

2.
A product may be part of a collection – a distinction useful for archiving and cataloging purposes. 

3.
The term product may be used to denote a product type, such as e.g. ENVISAT_ASAR_L1B_PRI data. 

4.
End users may distinguish between (input, "raw") data and products, i.e. the derived geophysical parameters.

Definition from EO Data Stewardship Glossary

Product Application

Useful references to published articles about the use of the data and user feedback received by the science and instrument teams about the products. Includes reports of any peculiarities or notable features observed in the products.

Definition from 423-SPEC-001 NASA Earth Science Data Preservation Content Specification