CNES PRIORITIES IN POLAR AND CRYOSPHERE RESEARCH

Polar Space Task Group – 3rd Session

Juliette Lambin, Steven Hosford

Wednesday, May 22th, 2013

Paris, France

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TLIN

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CNES MISSIONS FOR POLAR/CRYOSPHERE OBSERVATIONSRADAR: ALTIMETRY, SAROPTICAL IMAGERY

06/06/20132

Présentation programme SARAL – J. Lambin, février 20133

10 11 12 13 14 15 16 17 18 19 20 21 22

Wide‐Swath

altimetry

Saral/AltiKa Fr./India

09Launc h date

Altimetry12/01

3/02

Jason-1 France/USA Jason-3 Europe/USA

Proposed (A/B) 

Sentinel‐3B Europe

SWOT USA/France

Jason‐CS 

A and B Europe/USA

Sentinel-3A Europe

fp  July  2012

Geodetic orbit

ENVISAT Europe

Ocean missions @ CNES (various levels of contributions)

06/08

SalinitySMOS Europe

CFOSAT Fr./ChinaWind ‐

Wave

Ocean ColourPARASOL/POLDER France12/04 OCAPI ???

Concept (O)

Sentinel-3A-B Europe

06/06/20134

OCEAN WAVEFORM

06/06/20135

ICEBERG DETECTION FROM ALTIMETRY

GlobCurrent, March 7th, 2012 Juliette Lambin, CNES6

06/06/20137

SARAL SATELLITE FOR ARGOS AND ALTIKA

Cooperation with ISRO (India Space Research organization)Ka-band nadir altimetry missionHigher precision, shorter along-track sampling

Gap filler between ENVISAT & SENTINEL3Same orbit as ENVISAT (35 days, SSO)New Ka-band altimeter, higher precision, compact design, integrated radiometer/altimeterPOD: DORIS, LRAOther CNES payload Argos-3 instrument, X-band telemetry

Status: Launched by PSLV (ISRO) on Feb 26th Validation phase on-going

Data policy : ~ the same as JASON missionsPI: Jacques Verron (LEGI)

SARAL FIRST RESULTS

Altimeter noise Specifications Measured on 

ground In flight data

1Hz range 1.5 cm 0.9 cm 0.9 cm1Hz SWH 6.3 cm 5.7 cm 5 cm1Hz Sigma0  0.2dB* NA 0.012 dB

Excellent performance:

Real-time orbit < 5cm rms (no fine tuning yet)X-over analysis Jason2 –

SARAL indicate good consistencyRain impact under control

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Recul des glaces de mer Arctiques

Sea Ice Thickness accessible through altimetry

Antartica: 30 M km3: height change from  altimetry (ENVISAT)

m/an

T. Flament

Altika onboard SARAL: What will it bring to 

polar studies ?

1‐

Same orbit as ERS‐1, ERS‐2, EnvisatAbout 20 years of continuous measurements

Necessary for continental 

ice sheets

Altika onboard SARAL: What will it 

bring to polar studies ?

Ku2‐5 m

Ka2‐10 cm

2‐

Ka‐band (35 GhZ), penetration depth 

is about 50 times less  than Ku (13.6 

GhZ)

3‐

Smaller beam (0.55°

au lieu de 1.22 en 

Ku) => smaller footprint

Altika onboard SARAL: What will it 

bring to polar studies ?

4‐

AltiKa frequency and bandwidth 

induce a better vertical resolution 

(30cm wrt to 45 in Ku‐band)

Waveform with less 

penetration, smaller footprint, 

better sampling

5‐

Higher PRF in Ka‐band, along‐track 

sampling twice  the Ku‐band  one (175 

m instead of 350 m)

6‐

First time we will benefit from 

combination of active and passive 

measurement  (altimeter –

radiometer), in Ka‐band  

Altika onboard SARAL: What will it 

bring to polar studies ?

TWO SLIDES ON… CFOSAT CHINA-FRANCE OCEANOGRAPHY SATELLITE

China-France CooperationCurrently in phase C/DLaunch expected end of 2014

SWIM, new spaceborne instrument

technology innovations (antenna, on-board digital processing)Nadir chanel ~altimeter

SCAT, new concept of wind scatterometer

Ku-band, rotating fan-beam

Access to 2D wave spectrum with high angular resolution and with

global scaleJoint measurements of winds and wavesPI: Danièle Hauser (CNRS/LATMOS)

►SSO Orbit, 7am descending

►519 km altitude, 13‐days cycle

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SWIM INSTRUMENT

Surface Waves Investigation and Monitoring

Real aperture radar in Ku‐band6 incidence angles: 0°, 2°, 4°, 6°, 8°

et 10°

Rotation speed: 5.7 rpm

Will measure:Directionnal wave spectrum in the wavelenght range 

70‐500 m 

Accuracy: 10% on wavelength, 15°

on direction, 15% on 

spectral level around the peak 

SWH and wind speed from nadir

Normalized radar cross‐section from 0°

to 10°Absolute accuracy of ±1 dB, relative accuracy between 

incidences ±

0.1  dB

Airborne instrument in 2012 (KUROS)

CFOSAT ON ICE

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Secondary objectives–

polar ice sheet and land surfacemonitoring: roughness, vegetation and soil moistness in semi-arid regions, polar ice sheet characterics=>Multi-incidence normalized radar cross-section for estimatingSurface parameters (in particular roughness)

SWOT SURFACE WATER AND OCEAN TOPOGRAPHY

Hydrology and Oceanography mission Global, repeated high-resolution elevation measurements of ocean and inland water bodiesBaseline payload : Ka-band interferometric altimeter (KaRIn)Traditional altimetry payload

CNES budget secured in March’11 through General

Investment Fund

NASA/CNES Cooperation scheme approvedMission Concept Review succesfully passed in Sept 2012Phase A”

underway at CNES, “pre-phase A”

at NASA/JPL (Key Decision Point “A”

in a few days!)CNES involvement:Participation in KaRInDORIS, AltimeterPlatformGround segment

Launch ~2020 !

SIMULATION OF OCEAN DYNAMICS BY SWOTSIMULATION OF OCEAN DYNAMICS BY SWOT80

0 km

600 km

200 km

CNES INVOLVEMENT IN OCEAN OBSERVATION

Ocean sciences are one of the major interests of CNES Earth observation programsSupporting (and supported by) a strong scientific community through dedicated research funding Supporting several larger scope projects and initiatives (e.g. Mercator-Ocean, CORIOLIS and bioArgo, Boussole, GIS COOC…)Strong support to R&D (Instrument, mission concepts, data processing…)

In terms of satellites missions, the heavy weight is still on physical ocean observationaltimetry (Jason-1/2/3/CS, SARAL/AltiKa, SWOT, Sentinel-3, Hy-2A, )salinity (SMOS) wind/waves (CFOSAT),ocean color: PARASOL, Sentinel-3, “GEOCAPI”