mission status sea surface salinity - earth...

Mission StatusSea Surface Salinity

Understanding the Interactions Between the Global Water Cycle, Ocean Circulation and Climate

Gary LagerloefAquarius Principal Investigator

David Le Vine, Deputy PIYi Chao, Project Scientist 5th International SMOS Workshop:

November 29th – December 1st, 2004ESA-ESRIN, Frascati Italy

F. Raúl ColombSAC-D Principal Investigator

Salinity Mapping Satellite Mission:

2 Mission Status 5th International SMOS Workshop,November 29th – December 1st, 2004 ESA-ESRIN, Frascati It

• Aquarius Salinity Microwave Instrument

• Launch Vehicle

• Service Platform and SAC-D Science Instruments

• Mission Operations & Ground System

International Partnership Mission



Key Partners

Jet Propulsion Laboratory

Earth & Space Research

Goddard Space Flight Center

Aquarius• Deputy PI• Deputy PM• Deputy SE• Deputy MAM• GS Manager• LV I/F Engr.• Observatory I/F Manager

Aquarius

• Project Manager (PM)• Project Scientist (PS)• Project System Engineer (SE)• Project Mission Assu. Mgr. (MAM)• Instrument Manager

SAC-D• Principal Investigator (PI)• Project Manager (PM)• Systems Engineer (SE)• Instruments Manager• Service Platform Manager• MAM• GS Manager• Observatory I&T Manager• LV I/F & Logistics Manager

• Aquarius Principal Investigator (PI)



2003 2004 2005 2006 2007 2009-11Formulation (B) Implementation (C/D) Operations (E)

( 36 Months )

SELECTIONJuly 2002

CONFIRMATIONJune 2005

END OF MISSION2011LAUNCH

Sept 2008

PMSR PDR CDR PER PSR FRR

Science OperationsIOC

RMP

//

//

//2008

II&TMCR

Timeline

Final Rpt

SMOS 5th Science Workshop



• Monthly Global Sea Surface Salinity (SSS) Maps• 100 km Spatial Resolution• 0.2 psu Accuracy• Three Year Baseline Mission

Level 1 Science Requirements

WOA 2001 NOAA/NODC



•Global Coverage in 7 Days• > 4 Repeat Cycles per Month

Monthly Salinity Maps

Surface Validation

3 beams, 64 x 70, 72 x 86, 81 x 109 km instantaneous footprint ellipses across the 344 km wide swath.

Sun-synchronous exact repeat orbit6pm ascending nodeAltitude 657 km

Beams point toward the night side to avoid sun glint

Measurement Strategy



Aquarius Instrument

ICDS (Instrument Avionics)

Radiometer &ScatterometerFeed Horns (3)

Reflector

Service PlatformPanel

Sun Shade

Deployable Boom

ReflectorDeploymentMechanism

Sun Shade

• Sea surface brightness temperature measured by stable polarimetric radiometers operating at 1.413 GHz

• Sea surface backscattering cross-section measured by scatterometer operating at 1.26 GHz

• Fixed offset-feed parabolic reflector with three feedhorns provides three beams in a push-broom configuration; beams point towards night side orbit.

• Proto-flight instrument• Selective redundancy• Radiometer provided by GSFC• Scatterometer & instrument subsystems provided by JPL

• Instrument I&T at JPL• 400 kg; 450 W; 500 MB/day• Integration to S/P in Argentina• 3 yr lifetime



0.100.100.10Stability (K)0.060.060.06Radiometer Sensitivity (NEDT, K)

121212Integration Time (sec)81 x 109 km72 x 86 km64 x 70 kmFootprint Size (3 dB, one way)

41.833.823.9Incidence Angle (degrees)37.230.321.5Look Angle (degrees)89.591.392.4Beam Efficiency (%)5.55.35.1Beam Width (3 dB, degrees)

Outer BeamMiddle BeamInner BeamParameter

19 kbits/secData Rate~ 9 msecPulse Integration TimeVariableDicke Switching Cycle

Th, Tv, T+45, T-45Polarization344 kmSwath Width≤ 27 MHzBandwidth1413 MHzFrequency

657 km (655-685 km)Orbital AltitudeValueParameter

Key Radiometer Parameters



29.930.330.6Peak Gain (dBi)

12 bitA/D1 msecTransmit Pulse Length8.3 HzMeasurement Rep. Frequency

0.140.120.09Stability (dB)-29-31-34Noise-Equivalent Sigma-0 (dB)

0.080.100.14Radar Sensitivity (~100 looks, dB)88 x 118 km77 x 92 km67 x 74 kmFootprint Size (3 dB, one way)

41.833.823.9Incidence Angle (degrees)37.230.321.5Look Angle (degrees)5.95.75.4Beam Width (3 dB, degrees)

Outer BeamMiddle BeamInner BeamParameter

5 kbits/secData Rate

100 HzPRF200 WPeak Transmit power

HH, HV, VV, VH, <HH,HV*>, <VV,VH*>Polarization323 kmSwath Width4 MHzBandwidth

1260 MHzFrequency657 km (655-685 km)Orbital Altitude

ValueParameter

Key Scatterometer Parameters



X

Y

day night

Motion of Observatory



Orbit Swath Pattern

15263

•4 cycles every 28 days

•Equator swath gap ~50 km

•Meets Aquarius and SAC-D instrument and ground contact requirements

100 km

7-Day Exact Repeat Swath Detail1-Day Swath

Coverage



6 pm Ascending Node:

•Viewing only toward shadow side causes asymmetry in polar geographic coverage

•6 pm ascending gives greater geographic coverage of Arctic during summer ice melt (Aquarius)

•6 pm provides more exposure to darkness in the southern hemisphere (SAC-D HSC, Aquarius Southern Ocean)

Arc

ticA

ntar

ctic

Ascending Node and Polar Coverage



Key Parameter Summary

~87.5°N ; ~80°SLatitude Coverage

HH, HV, VV, VH, <HH,HV*>, <VV,VH*>Radar Polarization

Th, Tv, T+45, T-45Radiometer Polarization

23.9° 33.8 ° 41.8 °Incidence Angles

64 x 70; 72 x 86; 81 x 109 kmFootprint Size (3db)

~345 kmSwath Width

7 days (103 cycles)Repeat Cycle

657 km (655-685 km) / 98.01°Orbit Altitude/ Incl.



Observatory

Aquarius Instrument

Service Platform, CONAE & Partner

Instruments

• Science Instruments

NASA Instrument:

- Aquarius

CONAE Instruments:

- Microwave Radiometer (MWR)- High Sensitivity Camera (HSC)- Infra-red Camera (NIRST)- Data Collection System (DCS)- Technological Demonstration Package (TDP)

SAC-D Third Party Instruments:

- ICARE/SODAD (CNES)- ROSA (ASI)

• Service Platform (S/P)Redundant (functional/unit level)

- Deployable Solar Array- 3-axis stabilized

- GPS, Star Tracker, IRU, Inertia Wheels, Torque Rods, Magnetometer, Sun sensors

- Propulsion system & maneuvering thrusters- S- & X-band Communication linkObservatory



Instrument Objectives Specifications Resolution Owner

Aquarius

Understanding ocean circulation, global water cycle and climate interaction. Soil Measures over

Argentina

Integrated L-band radiometers (1.413Ghz)

and scatterometer (1.26Ghz)

Three beams: 64 x 70, 72 x 86, 81 x 109 km NASA

MWRPrecipitation rate, winds speed,

sea ice concentration, water vapour, clouds

23.8 and 37 Ghz H and V pol

.Bandwidht: .5 and 1 Ghz

< 40 km CONAE

NIRSTHot spots events, sea surface

temperature measurement

4, 11 and 12 µm Swath: 75 Km Tilt +/- 350 Km

150 meters CONAE

HSC Urban lights, electric storms, polar regions, snow cover

450-900 nm Swath: 700 Km

200-300 meters CONAE

DCS Data Collection System 401.55 Mhz uplink 2 contacts per day with 200 platforms CONAE

ROSA Atmospheric properties GPS Occultation Techniques

Horiz: 300 Km Vert: 300 m ASI

ICARE/SODADEffect of cosmic radiation in

electronic devices, distribution of micro-particles and space debris

I: three fully depleted Si and Si/Li detectors , S: four SMOS sensors;

I: 256 channels spectra, Sensitivity:

0.5 u part. at 10 km/ sec CNES

Technological Demonstration Package

Position, velocity and time determination

Inertial Angular Velocity

GPS Receiver Inertial Reference Unit

20 m, 1m/sec, .2msec ARW: 8*10-3 o/sec/ sqrt h CONAE

Aquarius/SAC-D Instruments Matrix

Summary



SAC-D ↔ Aquarius Synergy

CONAE Microwave Radiometer (MWR)•23.8 and 36.5 GHz •8 beams overlap Aquarius•Wind, rain, cloud water, sea-ice detection for Aquarius SSS retrievals

CONAE New IR Scanner Technology (NIRST)•75 km swath overlaps Aquarius inner beam•3.8, 11 and 12 µ•Supplementary SST•Primary application is detecting high temperature events (HTEs) over land (fires & volcanic events)

n1p1

p0NIRST

MWR

MWR



Landsat Image of the Andes Zone, more than 20 fires can be seen

The temperature and effective area affected by fires can be determined by using two IR channels: 3.8 and 11 µ.

Temperature determination can be improved using a third channel in 12 µ.

FIRESNIRST

CONAE NIRST



Enhanced HSC image (with DEM data)

Fire Detection with HSC

Snow Coverage Fire Detection

CONAE High Sensitivity Camera (HSC)



GPS Radio Occultation on SAC-C

ROSA (ASI)

SAC-D Instruments



ICARE/SODAD (CNES)

Results from ICARE on SAC-C

Computer simulation of space debris distribution

SAC-D Instruments



Risk List & Status

32,4,5

1

1

2

3

4

5

LIKELIHOOD

CONSEQUENCES

54321

Scatterometer on-orbit stability calibration42-25

On-orbit calibration stability verification.11-24

The Aquarius error budget.13-23

Long wave effect on backscatter46-22

Solar maximum brightness temperature correction40-51

Risk TitleAppro

achRiskID

Rank &Trend

New since last Month

Unchanged

Increasing (Worsening)

M - MitigateW - WatchA - AcceptR -Research

Decreasing (Improving)

ApproachLxC Trend**Criticality

High

Med

Low



Near Term Activity

Aquarius/SAC-D• PDR April-May 2005

• NASA April 26-28, 2005• CONAE May 31-June 2, 2005

Aquarius• MCR – June 28 2005• Bottoms-up salinity error budget reanalysis before PDR• Algorithm simulator tool prior to PDR Solar

contamination assessment by end 2004• Long wave backscatter analysis by end 2004

mission status sea surface salinity - earth...

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