ESA > Join & Share > EO Resources > Lexicon



Acquisition describes the complete process from and including sensing via optional on-board recording, downlink and reception, up to the reconstruction of instrument source packets on ground. See also acquisition planning.

Acquisition Date
Date of data acquisition. Note that in 24 hours the satellite describes several orbits: about 14 orbits per day for ERS-2, ENVISAT and Landsat 7.

Acquisition Station
A facility for acquiring satellite data and in some cases for archiving and performing production and shipment on demand. Data can be acquired only when the satellite (or the Data Relay Satellite) is seen by the station.

Area Of Interest
Geographic area relevant for the process. In its more general form it can be defined for example as one or more (or a combination of):

  • rectangle (usually with sides aligned with the latitude / longitude grid)
  • circle
  • polygon
  • name (of a site, a region, a country, a town, a river, etc., or of multiple sites together, like volcanoes)

Ascending Node
The point at which the satellite nadir crosses the Equator moving from South to North. (see Orbit)

Ascending Pass
See Satellite Pass.

The along-track direction.
Also scene size in the along-track direction.

Background Mission
A set of systematically implemented payload data acquisition rules. Examples of background missions are areas to be covered during specific periods of the year, like fields during the growing season, poles during ice formation, iceberg source areas during melting periods, etc. A background mission can also be linked to the acquisition campaign of a station, particularly for mobile stations.BaselineA configuration item that has been formally reviewed and agreed upon, that thereafter serves as a basis for further development, and that can be changed only through formal change control procedures.
Baseline (Intererometric)
In the context of interferometry, the distance between equivalent points in two orbits of the same or different satellites. This value varies along the orbit, depending on orbital parameters and orbit perturbations. Can be decomposed in perpendicular and parallel values. Also used for selecting pairs of frames best suited to specific applications. In case of Tandem acquisitions it represent the distance between the position of ERS-1 and ERS-2 with one-day interval.

The cycle is the period, in orbits or days, before the satellite will repeat the same coverage.

Data Product
The result of the processing of remote sensing data. Products are specific to each mission and sensor combinations. A data product can be an entire acquisition strip (the data segment continuously acquired by a ground station) or a single frame (a subset of the acquisition strip of standard length as defined by the WRS).

Data Set
Collection of EO products responding to the needs of a GMES Service Project. A Data Set is typically composed by products from several missions, gathered together to respond to the overall coverage or revisit requirements from the services.

A horizontal plane from which heights and depths are measured.

Descending Node
The point at which the satellite nadir crosses the Equator moving from North to South (see Orbit).

Descending Pass
See Satellite Pass.

Drifting Mission
A mission with the satellite orbit, on purpose or by chance, not tightly controlled. It causes the area seen by its instruments to continuously shift (its coverage is not repetitive).

Represents the standard unit of data as defined, for that Mission / Sensor, by the WRS, which specifies the size and location of each frame and its identification number. For a given mission, the same frame number means frames at the same Latitude.
In the inventory it is described by a set of attributes, which have validity for the entire scene / frame (e.g.: quality) or for a subset of it (e.g.: cloud coverage in Landsat scenes, which is provided for each quarter of the scene).

In the context of EO, a set of SW modules and algorithms allowing to implement complex data transformations, manipulations, elaborations, conversions, and of procedures implementing common methodologies and rules, defined or provided to enable, facilitate or control access to Services. Functions can include as necessary also non-EO data and the methods for accessing these data. A Function can be seen as a single black box providing a predefined set of functionalities.

Geographic Site
See Area Of Interest.

Ground Facility
Combination of elements required by a ground operations organization to perform an operational task. It can be a co-located set of elements – often the elements of a system domain - configured for one or several missions

Ground Range
The perpendicular distance from the ground track to a given object on the Earth's surface.

Ground Segment
Hardware and software Infrastructure with the function to permit satellite mission(s) operations. Usually includes Mission/Orbit and Attitude Control, Mission/Payload Planning, Data acquisition, Transfer, Processing, Archiving and Dissemination.

Ground Station
See Acquisition Station.

Ground Track
See Track.

Heterogeneous Data
Include structured / unstructured multi-media, multi-discipline EO related data, products, information and knowledge in computer compatible format.

Heterogeneous Data Handling
The set of functionalities permitting to ingest, archive, maintain, preserve, search, retrieve, recondition, deliver to users and exchange with other facilities Heterogeneous Data.

Hierarchical Data Format
The Hierarchical Data Format (HDF) is a library and platform independent data format for scientific data exchange and storage.. It was developed and supported by the National Center for Supercomputing Applications(NCSA). The earlier HDF4 is both a physical file format for storing scientific data and a collection of utilities and applications for manipulating, viewing, and analysing scientific data. The more recent HDF5 is a new design and implementation, intended to eliminate the limitations of HDF4 and provide new, high-performance features.

(Source: Gartner Group Glossary) The underlying technological components that comprise an organisation's systems architecture. The seven components of IT infrastructure are hardware, operating system, network, database, development environment, user interface and application.

Technique based on comparing the phase information returned with the radar signal from two or more acquisitions. With a precise knowledge of the orbit it permits to detect changes on Earth with a resolution in the centimetre range.

Collection of items identically structured and providing values of attributes pertinent to that collection. EO inventories contain attributes like orbit/frame number, frame corner co-ordinates, acquisition time, quality, etc.

An on-board equipment for data sensing.

The term groups software modules provided for enabling, facilitating or controlling access to Functions. Middleware can act in a distributed way across the network and is part of the Infrastructure.

A given satellite (e.g. ERS-1) with all its sensors.

Mission Phase
A time period during which a mission is operated with a specific set of characteristics, including orbital parameters, sensor settings, priorities for the various sensing activities.

Mission / Sensor
Since a mission can have on board more than one sensor, some possibly operated in more than one mode, only the combination of Mission / Sensor or Mission / Sensor / Mode identifies exactly the related data set.

Mission / Sensor / Mode
See Mission / Sensor.

A sensor and its on-board electronics can be operated in various modes (e.g. view angle, data compression method, etc.).

The projection of the satellite position on the Earth surface.

As a satellite orbits the Earth, it crosses the Equator twice per orbit: once going North (Ascending Node) and once going South (Descending Node).
A node can also represent further divisions of the orbit according to the applicable World Reference System. For example, 7200 nodes have been defined for ERS, with node 0 being the ascending node and node 7199 being the last node before the start of next orbit (i.e. before next ascending node).

A revolution of the satellite from one ascending node to the next one. For ERS, the orbit duration is about 6000 seconds. The first quarter of the orbit (from the ascending node up to the point closest to the North pole) is ascending, the next two quarters (down to the South pole) are descending, and the last quarter (up to the next ascending node) is ascending.

Orbit Node
See Node.

A satellite orbit is split in two parts: the ascending pass and the descending pass.

Payload Data Exploitation
Payload Data Exploitation refers to the activities associated with the operation of ground segment infrastructures and facilities, the provision of related data and information to user communities, and the stimulation of and the support to applications, services and data utilisation. The processes involved refer to Satellite Payload Scheduling, Data Acquisition and Archiving, Data and Information Processing and Distribution, User Information Services, Applications and Services Support. All processes might require the involvement of Data Management and Telematic systems.

After one complete cycle, the satellite starts to acquire the same scenes over again as it covers the same area on the Earth (same path number). Within each cycle, the orbits are numbered by the WRS according to their progressive coverage of the Earth (that is regardless of their sequence in time).

A contiguous set of orbits with the same mission characteristics (satellite orbital parameters, but also mission objectives).

See Data Product.

Radar Swath
Width of the imaged scene in the range dimension, measured either in ground range or in slant range.

Line of sight distance between the sensor and the target.
Also the width of the scene swath (usually perpendicular to the flight direction).

Raw Data
The data received on ground from the satellite prior to the application of any data processing algorithm.

Region Of Interest
See Area Of Interest.

See Frame.

RTD Projects
RTD Projects group a set of tasks aimed at feasibility analysis or at prototyping systems or sub-systems in technologically advanced areas and are normally managed through contracts.

RTD Packages
RTD Packages are usually limited study or research activities controlled through work packages, which are normally part of an ad hoc or a wider consultancy contract.

Satellite Cycle
See Cycle.

Satellite Nadir
See Nadir.

Satellite Pass
See Pass.

Satellite Path
See Path.

Satellite Phase
See Phase.

Satellite Track
See Path.

See Frame.

An on-board instrument or a subset of it. It includes limb looking, forwards, backwards and side-wards steerable sensors.

Sensor Swath
See Swath.

A Service is the repeated, regulated (usually by means of a Service Level Agreement) and agreed (via contract or agreement) or declared (with defined quality parameters) exploitation (for commercial or non-commercial purposes) of a function, processor or application. The output of a service includes data, products, information and solutions.

Slant Range
See Range.

Scene Status
Possible statuses for a scene are:

  • Available - data already acquired and stored
  • Planned - data are planned for acquisition
  • Visible - when the scene is visible by a station and could be planned

Small Mission
Small (Satellite) Mission can be characterised (in respect to traditional missions) by:

  • Reduced life cycle and costs
  • Carrying less instruments and more specific to given applications
  • More likely to fly in cluster with more frequent revisiting time
  • Supporting both autonomous and automation concepts

Steerable Sensor
Sensor which can be moved with telecommands from its nominal pointing angle, in order to acquire data with different view angles or from areas not under the satellite nadir.

A continuous sequence of data acquisition by a ground station (and therefore made of more scenes / frames). To be noted that the sensor can be continuously on even when crossing stations' visibility. Therefore one station will acquire one part of the data and another station another part of the data. The two strips might partially or fully overlap.

The width of the track on Earth of the sensor view angle.

Tandem Mission
During this combined mission phase, ERS-1 and ERS-2 were placed on the same orbit with one day difference and acquiring as much as possible data on the same areas.

Thematic Map / Category
A Thematic Map is a collection of georeferenced categories or values. Examples are Thematic Maps of vegetation type, cloudiness and precipitation, which provide the Categories (i.e. respectively the vegetation type, and values of mean annual cloudiness percentage, and mean annual precipitation) for a given area, suitably tiled (each cell might be 1 sq deg or of another size).

Time Line Display
Representation over time of events. Examples can be the scheduled activities represented by a signal in the y-axis against the time in the x-axis (the signal is normally zero and takes a value different from zero or changes colour when the activity is scheduled).

See Path.

World Reference System
In the context of EO, a reference system describing the ground coverage of sensors and products in a system formed by the ground track of the satellite and its subdivision into frames. A WRS is mostly a user interface aspect. However, using it in the internal inventory representation simplifies overall data handling, avoiding reference to precise data sensing time and permitting also to define attributes with values changing along the orbit (e.g.: quality, cloud coverage, etc.).

3D/4D Data
Loosely used to describe data that can be arranged or displayed in a 3D space, like Digital Elevation Models, geospatial, georeferenced, atmospheric, meteorological and Earth Observation instruments' data. The forth dimension usually refers to time.

Further definitions are vailable here

Acronyms, Abbreviations

ADApplicable Document
ADDArchitectural Design Document
ADEOSAdvanced Earth Observing Satellite
ADRArchitectural Design Review
AGFAdvanced Ground Facility
AIPArchival Information Package
AISAdvanced Inventory Server
AMORAutomated MOnitoring, control and Reporting tools for distributed facilities
AMSArchive Management System
ANSIAmerican National Standards Institute
AOIArea Of Interest
AOSAcquisition Of Signal
ARAcceptance Review
ASARAdvanced Synthetic Aperture Radar
ASPApplication Service Provider
ATSAcceptance Test Specification
AVHRRAdvanced Very High Resolution Radiometer
B2BBusiness to Business
BDSBrowse Data Server
BSSCESA's Board for Software Standardisation and Control
CAControl Authority
CAIDControl Authority Identifier
CANContent Aware Network
CAOControl Authority Office
CAOSControl Authority Office System
CAVECave Automatic Virtual Environment
CBIRContent-Based Image Retrieval
CCFComputer Compatible Format
CCNContract Change Notice
CCSDSConsultative Committee for Space Data Systems
CD-ROMCompact Disk Read Only Memory
CDRCritical Design Review
CEOSCommittee on Earth Observation Satellites
CFCCustomer Furnished Component
CFICustomer Furnished Item
CIDL· Configuration Items Data List
CIPCatalogue Interoperability Protocol
CORBACommon Object Request Broker Architecture
COTSCommercial Off The Shelf
DBMSData Base Management System
DDDDetailed Design Document
DDFDesign Definition File
DDUData Description Unit
DEDData Entity Dictionaries
DEDSLData Entity Description Specification Language
DEMDigital Elevation Model
DIPDissemination Information Package
DJFDesign Justification File
DLRGerman Aerospace Center
DPMDDetailed Processing Model Document
DRSData Relay Satellite
DSSDecision Support System
DVBDigital Video Broadcasting
DWData Warehouse
ECMWFEuropean Center for Medium Range Weather Forecast
ECSSEuropean Cooperation for Space Standardisation
EJBEnterprise Java Beans
EMITSESA's Electronic Mail Invitation to Tender System
EMMCFESRIN Multi-Mission? Central Facility
ENVISATENVironmental SATellite
EOEarth Observation
EOADEarth Observation Applications Department
EOEPEarth Observation Envelope Programme
EOPEarth Observation Programme (ESA Directorate)
EOP-AEarth Observation Programme - Applications Department
ERSEuropean Remote Sensing satellite
ESAEuropean Space Agency
ESRINEuropean Space Research INstitute
ESTMPEuropean Space Technology Master Plan
EVAESA Versatile Archive
FAQFrequently Asked Question
FDIRFault Detection, Isolation and Recovery
FEPFront End Processing
FOCFire Observation Constellation / Fuego Onset Constellation
FPFinal Presentation
fPARfraction of Photo Absorbed Radiation
GEOTIFFTagged Image File Format with geographic metadata
GIPGateway Interoperable Protocol (MUIS)
GISGeographic Information System
GMESGlobal Monitoring for Environment and Security
GPRSGeneral Packet Radio Service
GSGround Segment
GSFCGoddard Space Flight Center
GSPGeneral Studies Programme
GSTPGeneral Support Technology Programme
GUIGraphical User Interface
HCMMHeat Capacity
HMIHuman-Machine Interface
HTMLHyper Text Mark-up Language
HTTPHyper Text Transfer Protocol
IABImplementation Approval Board
ICDInterface Control Document
IDSInventory Data Server
IRSIndian Remote Sensing Satellite
ISIInternet Storage Infrastructure
ITSIntegration Test Specification
ITTInvitation To Tender
JERSJapanese Remote Sensing Satellite
JRCJoint Research Centre
LAILeaf Area Index
LANLocal Area Network
LOSLoss Of Signal. Line of Sight
LSTLand Surface Temperature
MACAOMember Agency Control Authority Office
MMIMan-Machine Interface
MOPMission Operation Plan
MOTSModifiable Off The Shelf
MSGMeteosat Second Generation
MUISMulti-Mission User Information Services
N/ANot Applicable
NASNetwork Attached Storage
NASANational Aeronautics and Space Administration
NCR· Non Conformance Report
NDVINormalised Deviation Vegetation Index
NJPLNASA Jet Propulsion Laboratory
NOAANational Oceanic and Atmospheric Administration
NPPNet Primary Productivity
NSSDCNational Space Science Data Center
NUARSNASA Upper Atmosphere Research Satellite project
OAISOpen Archival Information System
OSPOrbit Swath Propagator
PAProduct Assurance
PACProcessing and Archiving Centre
PAFProcessing and Archiving Facility
PDCCPayload Data Control Centre
PDFPortable Document Format
PDHSPayload Data Handling Station
PDRPreliminary Design Review
PDSPayload Data Segment
PMPProject Management Plan
QAQuality Assurance
QMSQuality Management System
QoSQuality of Service
QPQuality Plan
RBRequirements Baseline
RDReference Document
RDBMSRelational Database Management System
RFRadio Frequency
RIDReview Item Discrepancy
RISCReduced Instruction Set Computer
ROIRegion Of Interest
RSRemote Sensing
RTDResearch and Technology Development
RTMRequirements Traceability Matrix
SAMSoftware Administrators Manual
SANStorage Area Network
SARSynthetic Aperture Radar
SCMPSoftware Configuration Management Plan
SIPSubmission Information Package
SLAService Level Agreement
SOAPSimple Object Access Protocol
SOMSoftware Operators Manual
SoWStatement of Work
SPMPSoftware Project Management Plan
SPRSoftware Problem Report
SPRSystem Problem Report
SQAPSoftware Quality Assurance Plan
SQLStructured Query Language
SRDSystem Requirements Document
SRRSystem Requirements Review
SSDSoftware Specification Document
SSPStorage Service Provider
SSTSea Surface Temperature
STDSoftware Transfer Document
SUMSoftware Users Manual
SVVPSoftware Verification and Validation Plan
TBCTo Be Confirmed
TBDTo Be Defined
TIFFTagged Image File Format
TNTechnical Note
TRPTechnology Research Programme
TSTechnical Specification
TTPTechnology Transfer Programme
UMTSUniversal Mobile Telecommunications System
URDUser Requirements Document
VAIValue Added Industry
VASPValue Added Industry and Application Service Providers
VRVirtual Reality
W3CWorld Wide Web Consortium
WEUWestern European Union
WRSWorld Reference System
WWWWorld Wide Web
XMLeXtensible Markup Language

RTD Projects

ADARAdvanced Data Archive
ADASAdvanced Earth Observation Data Acquisition System
ArrayAnalysis of the use of antenna arrays for small EO receiving stations
ASCESAAn e-Science and Collaborative Environment for Space Applications
CATCompact Active Transponders for Ground Motion Monitoring
CoMuMission Planning for Constellations and Multi-use
CraterSurvey of algorithms for automatic recognition of impact craters
DEBATDigital EAST Based Access Tools applications
DISPDevelopment and Implementation of an Interferometric SAR Processor
DPFData Processing Framework for EO
EKNOSEO Knowledge Navigational System
ESECAnalysis and Demonstrator implementation of an e-commerce security infrastructure for spatial applications
GODISGRID-on-demand Infrastructure and Services
GREASEGrid-aware End-to-end Analysis and Service Environment
GREATGridAssist based EO and Science Tools
HICOD2000High-performance Coding, Protection and Trading of Satellite Images, using JPEG2000
HiProGenHigh level information Product Generation and formatting for specific applications
HiProGExHigh level information Products Generation Extension
ICDYImpact Crater Discovery
ISACEO User Information Systems Application Client
ISPInterferometric SAR Processor
KEOKnowledge-centric Earth Observation
KESEO domain specific Knowledge Enabled Services
KES-BEO domain specific Knowledge Enabled Services
KIMKnowledge driven Information Mining in remote sensing image archives
KIMVKIM Validation for EO archived data exploitation support
MAPS-AISMulti-mission Performing Catalogue and Analysis Tools for new EO instruments
MASSMulti-Application support Service System
MIRMultiple Image Registration Tools
MOSTMOdelling and Simulation Tools to support end to end applications
PRESSPrototype Environment for Services from Small Autonomous Missions
QUARCQuality Analysis and Reporting Computer
RDFARDF Semantic Web Technology Assessment
RTSReal Time Services for EO Data Distribution
SAGScatterometer Algorithm review for Gyro-less operations
SMOGImpact of Small Missions on earth-Observation Ground segment systems
SMOG-BImpact of Small Missions on earth-Observation Ground segment systems
SpaceGRIDStudy of GRIDS and collaborative environment for Space Applications
SURFSURvey and classification of advanced Feature manipulation techniques and tools for earth observation applications
UGEIUniversal Geometry Engine for EO Images
UGEIPUniversal Geometry Engine for EO Images - Preparation
ViCeMVirtual centralised system for mission planning
VREM3D/VR interactive Visualisation of environmental derived variables and REal Measurements
VRESVirtual REality System for earth observation applications
VRES-EVRES Extension for improved operability

Contributors to this page: .

Page last modified on Wednesday 12 of October 2011 15:09:00 CEST by .