CNES activities supporting Wide-Swath altimetry

Prepared by Eric Thouvenot & Hervé Jeanjean

Direction for Strategy and Programs - CNES

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-2

■ CNES contribution to WSOA/OSTM-JASON2 activities support to system/performance studies PhD grant (Alcatel/CNES LEGOS/JPL cooperation) definition/manufacture of 120W Ku-band TWTA (Thales) accommodation study (phase A/B) on-board PROTEUS platform

Past studies (1/2)

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-3

Past studies (2/2)■ CNES/LEGOS activities related to

hydrology from space

=> http://www.legos.obs-mip.fr/soa/hydrologie/hydroweb/ ■ CNES contribution to Water activities

support to system/performance studies support to ESA Core Mission proposal

=> satellite definition=> mission/system document submitted to ESA

=> Contact : Nelly Mognard

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-4

■ AltiKa related activities SARAL (Satellite with ARgos & ALtiKa) Mission :

cooperation between ISRO & CNES payload module provided by CNES : AltiKa (altimeter/radiometer), DORIS, LRA, +ARGOS3 (all

elements in phase C/D) satellite/launcher provided by ISRO : new SSB (Small Satellite Bus) platform launch : end 2009, on a 800-km, 6am-6pm SSO, cycle TBD

Back-up solution : AltiKa on OCEANSAT3 satellite (launch : 2012?)

AltiKa PI : Jacques Verron (LEGI); mission group with ~20-30 people with activities related to :

SARAL ocean performance (in combination with other altimetry missions) for NRT & offline products Coastal peformance (DIODE/DORIS + on-board along-track DEM coupled with altimeter tracking-

loop) Cloud/rain related activities (use of TOPEX/JASON, TRMM & MODIS data for simulation studies) Study about new products, and associated performance cal/val issues for :

– in-land waters– ice sheets

Foreign contributors to Mission Group are welcome

CNES will select AltiKa Co-Is through its next OST-ST call

Current activities (1/2)

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-5

Current activities (2/2)

■ Jason3 related activities support Eumetsat in the frame of the J3 Working Groups two main options :

minimal, low-cost, gap-filler approach (dedicated to ocean) or, precursor to a series of bigger missions (dedicated to ocean and possibly hydrology, possible WSOA-like instrument)

■ CNES continues to support French laboratories in Wide Swath science & applications new PhD grant at LEGOS

■ Call for phase 0 proposals at CNES in september, 2006 : ocean/hydrosphere mapper proposal ranked 4th out of 37 proposals

=> Phase 0 possible as soon as early 2007=> Possibly followed by phase-A and/or R&D studies in 2007/2008=> Coordination necessary with Eumetsat and US partners

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-6

Needs for Global, Satellite-based Observations of Terrestrial Surface Waters

■ Where is water stored on Earth’s land surfaces, and how does this storage vary in space and time? What is the global distribution of freshwater runoff delivered to the oceans and what is its inter-seasonal and inter-annual variability? What are the spatial dynamics of floods and how can we predict them? River discharge , lake and wetland storage of water are critical terms in the surface

water balance, but are poorly observed Gauges are incapable of measuring the diffusive flow conditions and related storage

changes for non-channelized flows (wetlands, floodplains) Declining of the gauging network, hard to maintain Political and Economic problems

■ Profiling altimetry does not sample all of the world’s fresh water bodies and provides almost no knowledge of wetlands flow

■ Instead of cross-sectional methods, the ideal solution is a spatial measurement of water height from a remote platform

Wide-Swath altimetry Workshop, October 30th & 31st, 2006 ET-7

Conclusions

■ Ocean and in-land applications of Water, HM, or OSTC missions well within CNES programmatic priorities, as recommended by the scientific community CNES will bring technical/funding support to the French involved laboratories Phase 0 (mission/system/satellite) feasible in 2007

■ In the short term : “CNES will not contribute to an operational, recurrent Jason3 mission” “CNES will bring its experience/expertise to any Jason2-FO mission”

■ In the mid-term, CNES could become a partner (subject to funding availability…) in a wide-swath mission dedicated to both oceanology and hydrology