AltiKa/SARAL project status – OSTST - HobartMarch 12-15, 2007 AltiKa/SARAL project status Jocelyne NOUBEL, CNES Pierre SENGENES, CNES

2AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 Summary 1.AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

3AltiKa/SARAL project status – OSTST - Hobart March 12-15, AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

4AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL mission context ■AltiKa/SARAL program is an answer to the need expressed by IGOS and GODAE since 2000  « Continuity of high accuracy, high resolution near-real time observations of the ocean surface topography is required. At least, 2 simultaneous altimetric missions are required (including one of the Jason reference class) » ■Program approved on December, 2005  Altimetric Gap filler between ENVISAT & SENTINEL3  Research oriented mission : - new, higher frequency, greater performance - potential new applications on ice, land, coast areas  …but with a consolidated architecture : conventional altimeter

5AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL mission scientific objectives ■AltiKa/SARAL central objective  Ocean meso-scale variability studies with an improvement of vertical and spatial resolution  Data assimilation in a global ocean model ■Contribution to :  Operational oceanography  Coastal altimetry  Continental waters  Inland ice sheet monitoring  Light rainfall and clouds climatology  Mean sea level  Sea state observation and forecasting  Geodesic reference system determination

6AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL mission and system highlights – Orbit ■AltiKa/SARAL mission orbit : same as ERS and Envisat orbits  Polar (incl. = 98.55°) Sun-Synchronous orbit (6:00/18:00), 800 km altitude, low eccentricity  Ground track  repetitivity period : 35 days  ground-track stability : +/- 1 km  Complementary to Jason2 ground-track in terms of spatial & temporal sampling

7AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL mission and system highlights – Payload ■A single frequency Ka-band altimeter (35.75 GHz +/- 250 MHz)  Improved vertical and spatial resolution  enhanced bandwidth (500 MHz) and increased PRF (~ 4kHz)  antenna footprint : 8.5 km in Ka-band, 12 km in K-band  reduced ionosphere effect in Ka-band authorizes mono-frequency altimeter  Ka-band limitations  no altimeter measurement for rain rate > 1.5 mm/h (data loss ~ 5% according to geographic areas)  Specific measurement processing required in case of clouds or low rain rate situations (~ 10%) ■A dual-frequency radiometer ( 23.8 GHz +/- 200 MHz & 37 GHz +/- 500 MHz )  required for wet troposphere correction on altimeter measurements  embedded in the altimeter instrument : share the same antenna ■POD system to achieve high accuracy orbitography performances  DORIS  required for achieving high accuracy orbitography performances on low earth orbit in a precisely monitored reference frame (mean sea level analysis)  contribution to DORIS system performance and monitoring ( for the benefit of all altimetry missions using DORIS)  Laser Retro-reflector Array  POD system calibration and guarantees minimum orbitography ■for coastal/inland applications, real-time coupling of the altimeter with DORIS

8AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL mission and system highlights – Mission Ground System ■AltiKa Mission Ground System  same definition of ocean products between JASON2 and AltiKa products  Same constraints for near real-time products processing and distribution  important synergy with JASON2 SALP/SSALTO developments  Processing algorithms (retracking, radiometer troposphere correction,…) has to be defined by the end of 2007 for ocean products, and at the beginning of 2008 for non- ocean products

9AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL program status ■AltiKa program has been approved by CNES Governing Board in December 2005  Authorization for Altimeter & Radiometer phase C/D commitment  Funding for AltiKa development (AltiKa mission payload, CNES Mission Center upgrades, system and science support studies) and for a 3-year exploitation (phase C/D/E)  AltiKa payload was planned to be embarked on Oceansat3 ISRO satellite, for a launch foreseen in mid  But Oceansat3 launch is now postponed to 2011/12 … ■May/June 2006 : CNES&ISRO proposition to embark AltiKa payload with Argos3 equipments, on a new platform, named SSB (Small Satellite Bus), which is being developed by ISRO ■July/November 2006 : CNES&ISRO technical studies to assess the feasibility of this new satellite configuration  SARAL satellite ■December 2006 : CNES commitment to develop the Integrated Payload Module accommodating AltiKa and ARGOS-3 payloads ■SARAL and ARGOS-3/SARAL MoUs signature by CNES and ISRO on February 23rd, 2007

10AltiKa/SARAL project status – OSTST - Hobart March 12-15, AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

11AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 SARAL sat. characteristics # Mass : 350/400 kg - SSB platform : ~200kg - Payload Module : ~150 kg # Power : 570 W (end of life) - SSB platform : ~ 205 W - Payload Module: ~ 195 w # Size m x 0.98m X 2.6 m -Solar panels : 1.2m x 1.4m (x2) Present AltiKa & Argos-3 payloads accommodation baseline on SSB platform : SARAL (SAtellite with ARgos and ALtika) ARGOS UHF ANTENNA MAGNETOMETER X-BAND ANTENNA TTC ANTENNA DORIS ANTENNA LRA ARGOS L-BAND ANTENNA ALTIKA ALTIMETER & RADIOMETER ANTENNA SSB PLATFORM INTEGRATED PAYLOAD MODULE STAR SENSORS

12AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 CNES/ISRO SARAL Responsibility Sharing ■ISRO responsibilities  Project Management, shared with CNES  Overall SARAL system engineering  PSLV Launch vehicle and services  SSB Platform  SARAL Satellite integration and test  Ground System & Operations  Satellite Operations Control Center  S-band network stations  X-band Hyderabad station  Data communication network  NRT and OFL products processing and distribution to users within India  Archiving  User interface ■CNES responsibilities  Project Management, shared with ISRO  Overall SARAL system engineering  Payload  AltiKa payload  ARGOS-3 payload  Integrated Payload Module  Support for SARAL Payload Module integration and test  Ground System & Operations  X-band stations  Data communication network  AltiKa Mission Center  NRT and OFL product processing software development  NRT product processing, archiving, distribution to users outside India with the support of EUMETSAT  OFL product processing and distribution to users outside India  DORIS product processing and distribution  Archiving of all telemetry and products  ARGOS3 Data Processing and Distribution System  User interface  ALTIKA System Coordination with other altimetry missions

13AltiKa/SARAL project status – OSTST - Hobart March 12-15, AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

14AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 SARAL system overview SARAL Payload Data SegmentSARAL Space Segment SARAL Satellite AltiKa & ARGOS3 Missions Centers Laser Community Outside INDIA AltiKa Users Within INDIA AltiKa Users SSB Integrated Payload Module Payload Interface Module CNES Payload ICU Flight Operation Control Center ARGOS L-Band Ground Stations Network DORIS Beacons Network EUMETSAT Center Auxiliary data providers ISRO Center CNES Mission Center IDS AltiKa NRT AltiKa OFL AltiKa NRT SARAL X-Band Ground Stations Network SARAL S-Band Ground Stations Network ARGOS Processing Center ARGOS User PSLV Launch vehicle AltiKa NRT

15AltiKa/SARAL project status – OSTST - Hobart March 12-15, AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

16AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa Data Products requirements ■Data products  Operational Service Specification (OSS) products (ocean type products)  Near-Real Time (NRT) products : OGDR  Off-Line products (OFL) : IGDR, GDR  Non-OSS products  1 product for coastal zone & inland waters (studies in progress to define specific ground retracking, content and format)  1 product for inland ice ■Data collection  The system shall be design to assure for each day that 80% of data collected on the satellite within 3 hours, and up to 100% of the data within 5 hours, can be made available to the users  Impact on on-board mass memory storage design, on ground station network design, set-up and operations, on communication network design, on ground processing performances ■Data latency  Near-Real Time product (OGDR)  75% of the data taken shall be made available to the users within 3 hours from acquisition  95% of the data within 5 hours

17AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa Data Products requirements - continued ■Data availability  GDR shall contain 95% of all possible over-ocean data during the mission life time, without any systematic gaps, taking into account the Ka-band constraints  5% of data loss due to rain rate > 1.5 mm/h according to geographic areas  10% of data to be processed with a specific retracking algorithm

18AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL Products definition ■Products definition closed to the Jason-2 one ■All O/I/GDR products will have the same format and very close scientific content  IGDR vs. OGDR :  Orbit quality, improved pole location data, restituted DORIS USO frequency, improved altimeter/radiometer calibrations, analyzed meteorological fields, GIM ionospheric and dynamic atmospheric corrections applied  OGDR product not generated in case of altitude or time-tagging information from DORIS/DIODE not available  Fast Quality Control & Check for OGDR : elementary and automatic controls only, product delivered in any case  Quality Control & Check for IGDR : product not delivered in case of pbs detected; fully validated by DUACS processing; possible reprocessing  GDR vs. IGDR :  Orbit quality, more accurate pole location data, more accurate dynamic atmospheric corrections  GDR is fully validated by experts; dissemination to users only once validated ■Taken into account Jason-1 heritage, products will be split into several files :  One file close to current Jason-1 NRT-SSHA, limited to 1Hz sampling  One file close to current Jason-1 I/GDR, containing 1Hz and 40Hz values  One file close to current Jason-1 SGDR, containing 1Hz, 40Hz and waveforms values. This file will not be generated in NRT

19AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 AltiKa/SARAL Product files Product OGDRIGDRGDR Non-ocean surface DR Content geophysical level 2 product Fast QC&C geophysical level 2 product QC&C fully validated geophysical level 2 product geophysical level 2 products for non-ocean surface Latency3-5 hours< 3 days~ 40 days 3 working days 1-HzOGDR-SSHAIGDR-SSHAGDR-SSHA 1-Hz 40-Hz OGDRIGDRGDR WaveformsS-IGDRS-GDR Structure acquisition segment pass Packagingsegmentday7-day arc

20AltiKa/SARAL project status – OSTST - Hobart March 12-15, AltiKa/SARAL Mission features 2.SARAL Responsibility sharing 3.SARAL System overview 4.AltiKa/SARAL Mission requirements  Data products requirements  Products definition 5.SARAL Project summary

21AltiKa/SARAL project status – OSTST - Hobart March 12-15, 2007 SARAL Project summary ■ AltiKa/SARAL system PDR : end of 2007 ■Payload instruments delivery  Altimeter&Radiometer instrument (antenna, electronic boxes) Flight Model: August 2008  DORIS receiver (BDR) Flight Model : April 2008  DORIS/AltiKa antenna flight model available since October 2006  LRA design and development phase : June 2007 to December 2008  ARGOS-3 equipments flight models delivery : July 2008 to December 2008  SARAL ICU and Payload Module design & development phase : July 07 to December 08  SSB spacecraft simulator delivery by ISRO to CNES : March 2008  CNES delivery of PIM electrical simulator to ISRO : July 2008 ■CNES Payload Module AIT : January 2009 – June 2009 ■CNES Payload Module delivery to ISRO : July 2009 ■Development of AltiKa mission specific upgrades on the CNES altimetry multi-missions Center  Specification phase : until mid-2007  Development phase : from mid-2007 until end of 2008  Validation, Technical & Operational Qualification: until end of 2009 ■Satellite AIT and launch campaign : July 2009 – December 2009