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Satellite Altimetry Status & Products – Part 1
J. Lambin, CNES
G. Dibarboure, CLS
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 2
Satellite altimetry: users needs as seen by space agencies
■One « high accuracy » reference mission TOPEX/Poseidon , Jason series (including Jason-3) => to be continued by
Jason-CS? Payload required:
Dual-frequency altimeter, Microwave radiometer, Precise orbit determination suite (GPS, DORIS, laser)
Orbit Minimizing tide aliasing: non-sunsynchronous, mid-inclination Suitable for POD (high altitude)
Data latency: 3h / 2 days / 2 month
■One at least (ideally 3) other altimetry missions (ERS, GFO, ENVISAT…) less demanding POD => post-calibrations using reference mission, SSO OK Mesoscale oriented => better spatial coverage, but longer cycles
■Future generation / alternatives Swath altimetry: SWOT Constellations (Iridium-NEXT?)
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 3
10 11 12 13 14 15 16 17 18 19 20 21 22
Jason-1 Fr./USA
ENVISAT ESA
High accuracy SSH from mid-inclination orbit
CRYOSAT-2 ESA
Medium accuracy SSH from high-inclination sun-synchronous orbit
Jason-2 Europe/USA
Jason-3 Europe/USA
Jason-CS/Jason-4 Europe/USA
Swath altimetry from high-inclination orbit (several orbit options)SWOT/WaTER-HM USA/Europe
Saral/AltiKa India/France
Jason-CS successor Europe/USA
In orbit Approved Planned/Pending approval Needed
Orbit to be assessed
Sentinel-3B, -3C, -3DSentinel-3A Europe
HY-2B, -2C, -2DHY-2A China
ERS-2 ESA
0908
Ocean Surface Topography Constellation Roadmap
GFO NOAA GFO-FO NOAA
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 4
Current altimetry missions
■ Jason1: in extended mission, fully operational
Moved to interleaved orbit with Jason-2 in Jan/Feb 09, after 6-month « formation flying phase »
Vulnerable to equipments failure risk
■ Jason-2: lauched in June 2008, OGDR distributed operationally since Dec
2008, IGDR distributed operationally since Jan 2009 GDR will be released after OSTST (July 2009) DUACS products already available Very good product quality
■ ENVISAT excellent synergy with Jason1 (T/P and ERS
complementarity further improved) S-band missing: degraded quality by lack of
ionospheric delay correction Will be put on a drifting orbit in 2010
Jason-1 vs Jason-2 SSH differences
DUACS map of SLA – J1+J2+EN
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 5
SARAL/AltiKa
■ Cooperative framework : CNES/ISRO
■ Altimetric Gap filler between ENVISAT & SENTINEL3 Research oriented mission :
new, higher frequency, greater performance potential new applications on ice, land, coastal areas
…but with a consolidated architecture : conventional altimeter
■ Tentative launch date : mid- to end-2010
■ Payload: AltiKa: Ka-band altimeter (higher accuracy, no need for a 2nd frequency)
+ Dual-frequency radiometer (sharing the same antenna) POD: DORIS/LASER
■ Orbit: same as ENVISAT (sun-synchronous, 35-day cycle)
■ Data policy : ~ the same as JASON missions (through CNES/ISRO RAs) Next India/France scientific workshop on 3-5 december in Ahmedabad International Research Announcement planned in 2009
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 6
Sentinel-3
■ ESA mission, in the frame of GMES program
■ Mission Profile: 7-year lifetime (consumables for 12
years) SSO orbit (10h descending), 27-day
repeat cycle, 98.65°
■ Satellite Payload: Ocean and Land Colour Instrument
(OLCI) Sea and Land Surface temperature
(SLST) Sentinel-3 Ku/C Radar Altimeter (SRAL) Dual Frequency MicroWave Radiometer
(MWR): POD: GPS/DORIS/Laser
■ Products: 3h / 1-2 days / final after POD
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 7
HY-2A mission description
■ Chinese oceanographic mission (+ French participation)
■ Launch planned Sept 2010
■ Payload: Dual-frequency altimeter Ku/C nadir 3-frequency radiometer 5-frequency scanning radiometer Wind/wave scanning scatterometer DORIS/GPS/LRA
■ Orbit (sun-synchronous 6-18, 99.35°): First 2 years with a 14-day cycle Then one year with geodetic orbit (168-day
cycle, 5-day approx. subcycle)
■ Products availability? Through DUACS multi-mission products (not
confirmed yet)
geodetic orbit after 3 days
One day of the 14-day orbit
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 8
Cryosat-2
■ ESA mission, to be launched in Nov 2009■ Objective: to determine fluctuations in the
mass of the Earth’s major land and marine ice fields
■ Mission description:■ Lifetime 3 years + 6 month comissioning■ Orbit
LEO, non sun-synchronous Repeat cycle: 369 days (30 d sub-cycle) Mean altitude: 717 km Inclination: 92°
■ Spacecraft and Payload recurrent from lost CryoSat 1
■ Instruments SIRAL (SAR/Interferometric Radar Altimeter):
Low-Resolution / SAR / SARIn modes KU-band (single frequency, no radiometer)
POD from DORIS and laser
■ Ocean data availability not confirmed yet, studies under way
Thermal Radiator
MagnetometerStar Trackers
SIRAL Antennas
Laser Retroreflector
DORISAntenna
X-Band DownlinkAntenna
S-Band Communications
Antenna
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 9
Jason-3
■ NOAA/EUMETSAT cooperation with CNES & NASA contributions CNES in-kind contribution : Proteus platform , system engineering, and manpower equivalent to
JASON/OSTM (i.e. about one third of European part of the program) Launch : mid-2013
■ Mission design: Jason-2 like■ Pending approval (in December 2009)
… and Jason-CS?
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 10
Surface Water & Ocean Topography (SWOT)
•Mission combining research needs associated to hydrology and oceanography :
- mapping of water level for rivers, lakes, and oceans (including coasts)
•Principle : Wide-swath interferometric, Ka-band altimeter
•Recommended by the US Decadal Survey
•Submitted in the frame of the Cnes Scientific Prospective Seminar (march, 2009)
•Cooperation scheme : TBD (NASA/CNES/…)
•Phase 0 in 2007, pre-phase A & phase A in 2008/2009
•Launch possible in ~2016
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 11
Conclusions
■There is a rich panel of missions under development or planning => let us wish they will all succed!
■Space agencies (NASA, CNES) tend to put as priority innovative missions Promising in a long term perspective, but Potential issues in the continuity of the long-term record Some effort is required to secure the transition to operational agencies of
already mature concepts
■Multiple missions decided/developed by multiple agencies/countries Coordination not guaranteed, higher programatics risk Data availability on a case-by-case basis Efforts from CEOS (through NOAA and EUMETSAT) to improve altimetry mission
coordination
■GODAE could (and should) be more vocal about their needs
2nd GODAE Observing System Evaluation Workshop - June 2009 – J. Lambin 12
TOPEX/POSEIDON (CNES/NASA)
LauncherDORIS & POSEIDON
Mission Center
Reference missionOcean Large scale
Earth reference system
SPOT2 (CNES)DORIS
SPOT3 (CNES)DORIS
SPOT4 (CNES)DORIS
SPOT5 (CNES)DORIS
1990
2000
Jason-1 (CNES/NASA)Satellite bus
DORIS & POSEIDONControl & Mission Center
ERS-1 (ESA) Altimeter algorithm
ENVISAT (ESA)DORIS
Altimeter ProcessingArchive & distrib.
ERS-2 (ESA)
experiment
operational
CRYOSAT2 (ESA)DORIS
Jason-2 / OSTM (CNES/NASA/EUMETSAT/NOAA)
Satellite busDORIS & POSEIDON
Control & Mission Center
ALTIKA/SARAL(CNES/ISRO)
Altimeter, radiometer, DORIS, Lra
Process, archive & distrib.
SALP : Altimetry and precise positioning service
MERCATOR : assimilation, forecastCNES / SHOM / METEOFRANCE / IFREMER / CNRS / IRD
PLEIADES (CNES)DORIS
2005CRYOSAT (ESA)DORIS
2010
HY-2 (CNSA)DORIS
CNES involvment in altimetry
Complementing missionmesoscale, ice
Sentinel-3A (ESA)DORIS