https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 24.3 2026-07-08T10:51:38.222Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/platforms/02c85d04-228e-4bf3-bb03-d72c22681dff ERS-1 The first European Remote Sensing Satellite ERS-1, launched on 17 July1991 at 01.46 UTC, operates in a sun-synchronous, near-polar orbit atan altitude of 785 km and an inclination of 98.5 degrees, known as thereference orbit.ERS-1 was conceived as an orbiting platform that would be capable ofmeasuring, on a global scale, the Earth's atmospheric and surfaceproperties with a high degree of accuracy. In fact it uses advancedmicrowave techniques to collect global measurements and images (muchof the data are collected from remote areas such as the southernoceans and the Antarctic) independently of time of day and weatherconditions. It also undertakes the measurement of many parameters thatare not covered by existing satellite systems, including those of seastate, sea surface winds, ocean circulation and sea/ice levels.Satellite characteristics:--------Platform: based on the SPOT Multimission PlatformPower supply: 4 x 24 Ah batteries; 1.8 kW from solar arrayAttitude control: 3-axis stabilised earth pointing, withoption of 9.5 degrees offset in Roll-Tilt Mode (RTM)Total mass: 2400 kg (at beginning of mission)Overall length: 11.8 mSolar array: 11.7 m x 2.4 mSAR antenna: 10.0 m x 1.0 mScatterometer antennas: fore/aft 3.6 m x 0.25 m; mid: 2.3 mx 0.35 mRadar Altimeter antenna: 1.2 m diameterDesign lifetime: 2-3 years---------ERS-1 carries on-board a number of instruments consisting of a coreset of active microwave sensors supported by additional, complementaryinstruments: the Active Microwave Instrument (AMI), which combines aSynthetic Aperture Radar (SAR) operating in image or wave mode and awind scatterometer, the Radar Altimeter (RA), the Along-Track ScanningRadiometer and Microwave Sounder (ATSR), the Precise Range andRange-rate Equipment (PRARE) and Laser Retroreflectors (LRR).The primary objective of the ERS-1 mission is the monitoring of oceansand sea ice providing essential data for:- improved representation of oceans/atmosphere interactionsin climatic models- major advances in the knowledge of ocean circulation andtransfer of energy- more reliable estimates of the mass balance of the Arcticand Antarctic ice sheets- better monitoring of pollution and dynamic coastalprocesses- improved detection and management of land use changeThe ability of ERS-1 to acquire vast global data sets of ocean,atmosphere, ice and land phenomena contributes to the following fieldsof study:- Ocean/Ice: ocean circulation, global wind/waverelationships, sea ice and iceberg monitoring, etc.- Physical Earth: accurate determination of the oceangeoid, forestry, glaciology, geology and agriculturestudies, etc.- Climate: contribution to the World Climate ResearchProgramme and to the World Ocean Circulation Experiment- Weather and Sea: short and medium-term weatherforecasting, sea surface state forecasting, wind speed anddirection, location of pelagic fish through the monitoringof temperature frontsRelation between ERS-1 instruments and missionobjectives------------------------------------------------------------Weather forecasting: AMI wind modeSea-state forecasting: AMI, wave and wind modesOffshore activity: Altimeter, ATSR, AMI in wave and windmodesShip routing: Altimeter, ATSR, AMI in wave and wind modesFisheries (fish location): (Altimeter), (ATSR), AMI inwind modeSea and iceberg monitoring: Altimeter, ATSR, AMI in imagemodeOil and pollution detection: ATSR, AMI in image modeCoastal process: ATSR, AMI in image modeLand applications: (Altimeter), ATSROcean circulation: Altimeter(1), ATSR, (AMI in wave mode)Ocean tides: Altimeter(2)Wind fields(3): Altimeter, AMI (in image mode), in wave andwind modeWave fields(3): Altimeter, AMI (in image mode), in wave andwind modePolar oceans: Altimeter, ATSR, AMI in all modes.Land ice: Altimeter, AMI (in image mode)Sea-surface temperature: ATSRMarine biology: (ATSR)------------------------------------------------------------( ) indicates limited applicability(1) For large-scale circulation, accurate orbitdetermination over short arcs is required(2) For solar tides, measurements from other satellites incomplementary orbits are required(3) The altimeter and active microwave instrumentation aremutually supportive in deriving the wind and wave fieldsThe complexity of the ERS-1 mission, which effectively consists of acombination of several different missions, requires a very carefulapproach when planning the mission operations. Taking into account thedifferent mission objectives, and attempting to satisfy them in aquasi-optimal way in the course of ERS-1's lifetime, has held to thedefinition of phases of activity during the mission:- Phase 0: Orbit acquisition, initial switch-on andfunctional check-out (2 weeks after the launch)- Phase A: The Commisioning phase, using a 3 day repeatcycle (25 July 1991-10 December 1991)- Phase B : The first ice phase, using a 3 day repeat cycle (28 December 1991-1 April 1992)- Phase R: The Roll-Tilt phase, using a 35 day repeat cycle (2 April 1992-14 April 1992)- Phase C: The first multi-disciplinary phase, using a 35day repeat cycle (14 April 1992-23 December 1993)- Phase D: The second ice phase, using a 3 day repeat cycle (23 December 1993-10 April 1994)- Phase E: The first geodetic phase, using a 172 day repeatcycle (10 April 1994-28 September 1994)- Phase F: The second Geodetic Phase, using a 172 dayrepeat cycle (28 September 1994-21 March 1995)- Phase G: The second Multi-Disciplinary Phase, using a 35day repeat cycle (21 March 1995-10 March 2000)In the first half of April 1992, the satellite was operated in aRoll-tilt-mode (RTM) to allow SAR imaging at a different viewangle. In fact by rotating the satellite body around its velocityvector (so-called 'Roll-tilt mode') the angle at which all theinstruments look at the Earth can be varied. This allowsexperimentation with the SAR at an incidence angle of 35 degreesinstead of the standard 23 degrees, thereby permitting analysis of atotally different set of signatures from objects on the Earth'ssurface, including in particular vegetation.Related URL:The ERS Missions: http://earth.esa.int/ersERS-1 Design: http://earth.esa.int/ers/satconcFor any query, please refer to:ESA/ESRIN Earth Observation Help Deskhttp://earth.esa.intGroup: Platform_Details Entry_ID: ERS-1 Group: Platform_Identification Platform_Category: Earth Observation Satellites Platform_Series_or_Entity: ERS Earth Resource Satellite Short_Name: ERS-1 Long_Name: European Remote Sensing Satellite-1 End_Group Group: Synonymous_Platform_Names Short_Name: ERS-1 End_Group Group: Platform_Associated_Instruments Short_Name: ATSR Short_Name: RA Short_Name: SAR Short_Name: AMI End_Group Group: Orbit Orbit_Altitude: 782 to 785 km Orbit_Inclination: 98.52 deg Period: 100 min Repeat_Cycle: 3-day, 35-day and 176-day Orbit_Type: LEO > Low Earth Orbit > Polar Sun-Synchronous End_Group Creation_Date: 2007-09-14 Online_Resource: http://earth.esa.int/ers/satconc/ Online_Resource: http://earth.esa.int/ers/ Online_Resource: http://www.astronautix.com/craft/ers12.htm Sample_Image: http://earth.esa.int/icons/eeo/_ers-1_fully_deployed.gif Group: Platform_Logistics Launch_Date: 1991-07-17 Launch_Site: Kourou, French Guiana Design_Life: 2-3 YRS Primary_Sponsor: ESA End_GroupEnd_Group