Eric J. LindstromApril 2008

NASA Ocean Satellite Missions

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OUTLINE

• NASA operating missions (13, 6 ocean)• NASA missions in implementation and formulation

to launch 2008-2015 (9, 4 ocean)• NASA missions beyond 2015 (11, 5 ocean)• Merging of scientific disciplines in PO and

hydrology in SWOT• Ocean Surface Topography Constellation• Funding the development of high resolution

physical oceanography and hydrology (“pre-SWOT research”) in the coming years.

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NASA Ocean Missions

SeaWiFSSSM/ISARs (variety)AVHRRMetop (OVSW)Color (MERIS)

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Missions in Development (launch by 2015)

OSTM6/2008

OCO12/2008

GLORY2/2009

NPP9/2009

AQUARIUS5/2010

LDCM7/2011

GPM6/2013, 6/2014

ICESAT-22015SMAP 2012

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Decadal Survey Mission Mission Description Orbit Instruments

HyspIRI Land surface composition for agriculture and mineral characterization; vegetation types for ecosystem health

LEO, SSO Hyperspectral spectrometer

ASCENDS Day/night, all-latitude, all-season CO2 column integrals for climate emissions

LEO, SSO Multifrequency laser

SWOT Ocean, lake, and river water levels for ocean and inland water dynamics

LEO, SSO Ka-band wide swath radarC-band radar

GEO-CAPE

Atmospheric gas columns for air quality forecasts; ocean color for coastal ecosystem health and climate emissions

GEO High and low spatial resolution hyperspectral imagers

ACE Aerosol and cloud profiles for climate and water cycle; ocean color for open ocean biogeochemistry

LEO, SSO Backscatter lidarMultiangle polarimeterDoppler radar

NASA Mid-Term Missions (5/15 total)

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*Cloud-independent, high temporal resolution, lower accuracy SST to complement, not replace, global operational high-accuracy SST measurement

Decadal Survey Mission Mission Description Orbit Instruments

LIST Land surface topography for landslide hazards and water runoff

LEO, SSO Laser altimeter

PATH High frequency, all-weather temperature and humidity soundings for weather forecasting and SST*

GEO MW array spectrometer

GRACE-II High temporal resolution gravity fields for tracking large-scale water movement

LEO, SSO Microwave or laser ranging system

SCLP Snow accumulation for fresh water availability

LEO, SSO Ku and X-band radarsK and Ka-band radiometers

GACM Ozone and related gases for intercontinental air quality and stratospheric ozone layer prediction

LEO, SSO UV spectrometerIR spectrometerMicrowave limb sounder

3D-Winds(Demo)

Tropospheric winds for weather forecasting and pollution transport

LEO, SSO Doppler lidar

NASA Far-Term Missions (6/15 total)

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Decadal Survey missions individually and as “tier” groups pull togetherScientific disciplines and community groups in new and challenging ways.

We are embracing this as a step forward in the development of EarthSystem Science and the maturation of the Earth Observing System atNASA.

SWOT is leading the “Tier 2” missions in implementation and we shouldtake care to serve as a model of how to serve two previously-separatedscientific disciplines (physical oceanography and land surface hydrology).

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Ocean Surface Topography Constellation Roadmap

Jason-1 Fr./USA

ENVISAT ESA

High accuracy SSH from mid-inclination orbit

CRYOSAT-2 ESA

GFO US

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

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SWOT FY08 ActivitiesWater Storage Study (OSU)

• Conduct a study to assess the measurement requirements for determining global fresh water storage and storage change. Global water storage and storage change are two of the main science questions for the SWOT hydrology goals, but their implications in terms of instrument measurement requirements have not been fully addressed in past studies.

Submesocale Workshop/Report • Conduct a workshop to address the capabilities of the SWOT mission to measure ocean mesoscale and sub-mesoscale phenomena. Unlike

the ocean basin-scale measurement requirements, which have been studied for past altimeter missions, the ocean mesoscale and sub-mesoscale measurement requirements for SWOT are not fully understood. Characterizing the ocean mesoscale and sub-mesoscale, where most of the ocean kinetic energy generation and dissipation takes place, is one of the primary science goals of the SWOT mission.

Orbit Study• Conduct a study to determine a family of orbits that will be used during the SWOT mission. The SWOT orbit determines the design and

performance of the instrument payload. Although some orbit definition activities have been conducted in the past, they are insufficient at this time for mission design. The orbits will be designed to providing full coverage of the SWOT regions of interest, minimizing tidal aliasing and orbit error, and optimizing the temporal and spatial sampling of the phenomena to be studied by SWOT.

Instrument Design/Simulator• Determine implementation options for the SWOT instrument. Determine system performance for ocean and land data and produce a

detailed error budget for the mission scenarios defined by the science team. Build an instrument and mission simulator capable of generating simulated science data for science team evaluation and to conduct the studies defined below. Identify key technology drivers and a risk reduction plan for future year activities.

Wet Troposphere Study• Examine the impact of wet tropospheric errors across the swath, in coastal regions, and over land. The wet troposphere delay constitutes

one of the main unknowns in the SWOT error budget, especially in coastal regions and over land. This task will utilize high-resolution regional weather models, measurements, and the instrument simulator defined in task 5 to determine the wet tropospheric component to the SWOT error budget.

Calibration Study• Conduct studies to determine calibration schemes for correcting roll and systematic phase errors in the SWOT data. Roll and systematic

phase errors cannot be calibrated by the instruments directly, but must rely on calibration using the payload data and post-processing. These are the dominant contributors to the SWOT error budget if uncalibrated. The calibration schemes to be studied will use ascending/descending cross-overs of the nadir altimeter and the interferometer over the ocean. Over land, calibration using available digital elevation models will be used. The effectiveness of the calibration schemes depends on the orbit selected and the effects of the wet tropospheric delays, studied above.

Simulated Science Products• Generate simulated science data sets to be studied by the SWG to assess different mission scenarios and the science impacts of the

SWOT mission.Management/Reports

• Prepare a Level-1 science requirement document.• Prepare a follow-on task plan, if requested.• Prepare a final report

Spacecraft Study• Derive the spacecraft requirements for the SWOT mission and prepare a Request for Information (RFI) to spacecraft vendors to assess the

cost and feasibility of the SWOT mission on existing, modified, or planned US spacecraft buses. Provide an assessment of the CNES spacecraft study results. Serve as a point of contact between NASA and CNES regarding spacecraft technical issues.

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Funding Future Research

NASA is funding SWOT studies for $525K in FY08 and projected $2M inFY09. Beginning in 2009 I hope to be able to fund a small number of proposalsfocused on high resolution ocean surface topography. (~$400K/yr)

These will supplement the Ocean Surface Topography Science Team.

We should also begin to examine how we can draw forward operational partners or specific applications. NASA has designated an Applications Program Scientist for the Tier 2 missions (John Haynes) and I serve as co-lead of a NASA-NOAA team trying to accelerate the transition of satellite measurement capabilities from NASA to NOAA.