nasa gifts measurement concept overview nasa gifts measurement concept overview 4 th workshop on...
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NASA GIFTS Measurement Concept OverviewNASA GIFTS Measurement Concept Overview4th Workshop on Hyperspectral Science (MURI, GIFTS, GOES-R)
University of Wisconsin – Madison (April 27-28, 2004)
20/20 Vision (Weather in Our Palm)20/20 Vision (Weather in Our Palm)
By the year 2020, mankind will have the By the year 2020, mankind will have the technology (observations and models) to technology (observations and models) to
digitize the earth’s surface and its atmosphere digitize the earth’s surface and its atmosphere with a resolution of 1 km and 1 minute with a resolution of 1 km and 1 minute
AndAnd
Every individual on earth will have personal Every individual on earth will have personal and timely access to weather observations and and timely access to weather observations and accurate weather forecasts through a “palm” accurate weather forecasts through a “palm”
computer/display unitcomputer/display unit. .
2020 Vision Strategy2020 Vision Strategy
Surface-basedRemotely Sensed
Integrated Data ProductsIntegrated Data Products
Environmental Satellites
METOP(Europe)
NPOESS(USA)
ENVISAT(Europe) EOS
(USA)
ADEOS(Japan)
FY POLAR(China)
FY GEO(China)
Hyperspectral Atmospheric Sounder EvolutionHyperspectral Atmospheric Sounder Evolution
Nimbus 3 & 4 IRIS/SIRSIRIS/SIRS
(1969-1972)
Nimbus 5/ITPRITPRITOS/ITOS/VTPRVTPR
Nimbus 6/NOAA HIRSHIRSGOES/GOES/VAS & HIRSVAS & HIRS
(1972-2009)
METOP-IASIIASI (2005- )
NPP/NPOESS/CrISCrIS(2006- )
AircraftNAST-I / SHISNAST-I / SHIS
(1995 - )
NMP NMP GIFTSGIFTSGOES-HESHES(20??- )
First Satellite Sounders
Hyperspectral Resolution
US Hyperspectral Resolution Sounder
GeostationaryImaging 4-d
T,q,“V”V” Sounder
High Resolution Interferometer Sounder (HISHIS)
(1985- )
High Horizontal Resolution
Hyperspectral Resolution Imagery
European Hyperspectral
Resolution Sounder
ADEOSIMGIMG
(1996-1997)(1996-1997)
First Satellite Hyperspectral Resolution Sounding Spectrometers
FTS Grating
AquaAIRSAIRS
(2002- )
Hyperspectral Atmospheric SoundingHyperspectral Atmospheric Sounding
The Infrared Radiance Spectrum
AIRS Hyperspectral Atmospheric SlicingAIRS Hyperspectral Atmospheric Slicing
wavenumbers (cm-1)
2000 2500 3000 3500
rela
tive
inte
nsi
ty
0
1
2
3
4
5
6
7
2129 cm-1 (4.7 µm)
2314 cm-1 (4.3µm)
2314cm-1 (high gain)
Images from Two Single Spectral Samples (Left)And Spectra from Two Different Spatial Samples (Below) Observed With a 128 x 128 Imaging FTS
Spectrum for Pixel (37,64) on face
Spectrum for Pixel (90,63) in breath
4.3 µm (2314 cm-1)CO2 Absorption Band
(3.0 µm)(5.0 µm)
Hyperspectral ImagingHyperspectral Imaging
Objective of the Geo-Sounder - Water Vapor MotionObjective of the Geo-Sounder - Water Vapor Motion
4-d Digital Camera:4-d Digital Camera:
•
Horizontal:Horizontal: Large area format Focal Plane detector Arrays
Vertical:Vertical: Fourier Transform Spectrometer
Time: Time: Geostationary Satellite
EO-3 “GIFTS”
GGeostationary IImaging FFourier TTransform SSpectrometerNew Technology for Atmospheric Temperature, Moisture, Chemistry, &
Winds
GIFTS Sampling CharacteristicsGIFTS Sampling Characteristics• Two 128x 128 Infrared focal plane detector arrays with 4 km footprint size
• Two 512 x 512 Visible focal plane detector arrays with 1 km footprint size
• Field of Regard 512 km x 512 km at satellite sub-point
• Ten second full spectral resolution integration time per Field of Regard
• ~ 80,000 Atmospheric Soundings every minute
GIFTS IR Measurements and ProductsGIFTS IR Measurements and Products
Products:Water vapor (soundings, fluxes, winds)
Temperature (sounding, stability)Carbon monoxide concentration (2 Layers)
Ozone concentration (4 Layers)Surface Temperature and emissivity
Clouds (altitude, optical depth, microphysical properties, winds)Aerosol Concentration and Depth
(8.8 to 14.6 microns) (4.4 to 6.1 microns)
Spatial Resolution130m/km flight alt.(2.6 km from 20km)
Swath Width2 km /km flight alt.(40 km from 20 km)
Water Vapor Mixing Ratio( Uncorrected)
NAST-I Validates GIFTS ConceptNAST-I Validates GIFTS Concept
Temperature (K)
Relative humidity (%)
• Instrument Characteristics – infrared Michelson interferometer (9000 spectral channels) 3.5 – 16 microns @ 0.25 cm-1
• Aircraft Accommodation – ER-2 Super pod & Proteus Underbelly pod
• Radiative Measurement Capability– calibrated radiances with 0.5 K absolute accuracy, 0.1 K precision
Tracks over ARM-site
NAST-IWater Vapor TrackingDemonstrates GIFTS
Wind Profiling Technique
δt~35 min
60 km x 40 km
WindWindMeasurementMeasurement
ER-2 NAST H2O Vs Twin Otter Doppler LIDAR Winds
0 90 180 270 360Direction (Degrees)
1000
900
800
700
0 4 8 12 16 20
Pre
ssu
re (
mb
)
Speed (mps)
February 11, 2003
36N, 121.6W
GOES - IR
X
Off California Coast
Geostationary Hyperspectral MeasurementsGeostationary Hyperspectral Measurements
Observation Capability Will Observation Capability Will RevolutionizeRevolutionize
Weather ForecastingWeather Forecasting
• Hurricane landfall (steering wind profiles)
• Tornadic storms (stability change monitoring)
• Nowcasting (rapid measurement update)
• Numerical prediction (initial p,T,q,V data)
• Air quality forecasts (O3 and CO transport)
What About Clouds ????
Cloud Effects on RetrievalCloud Effects on Retrieval
Cloud Tops Moist Layers
PBL Ht
Cloud Tops
OpaqueClouds
Non-opaqueClouds
Non-opaqueClouds
NAST I-HOP June 12, 2002 Over Oklahoma
Cirrus Cloud “Venetian Blind Effect”Cirrus Cloud “Venetian Blind Effect”
•
These retrievals, uncorrected for cloud attenuation, demonstrate the ability of a high spatial resolution
sounder to sense the spatial structure of moisture below a scattered and semi-transparent cirrus cloud cover
16.0 UTC
14.9
13.8Depressions due to Cloud Attenuation
Tem
perat u
re ( K)
Log
10 { VM
R (g/K
g)}
Basis for Cloud Training Algorithm!Basis for Cloud Training Algorithm!Radiance Spectra Carry Information on Cloud Phase
and Microphysical Properties
Wavenumber (cm-1)
Cloud Retrieval Training !Cloud Retrieval Training !• Perform a realistic simulation of clouds for synthetic EOF radiance training• Diagnose cloud layer from radiosonde relative humidity profile
– A single cloud layer (either ice or liquid) is inserted for the highest level of cloud diagnosed from the input radiosonde profile. If a second cloud layer exists it is represented as an opaque cloud.
• Use parameterization of Heymsfeld’s* balloon and aircraft cloud microphysical data base (2003) to specify cloud effective particle radius, re,
and cloud optical depth, , (i.e., re= a / [ - b]) .– Different habitats can be specified (Hexagonal columns assumed here)– Different clouds microphysical properties simulated for same radiosonde using random number generator to specify visible cloud optical depth within a pre-specified range. 10 % random error added to parameterized effective radius to account for real data scatter.
• Use UW/Texas A&M “lookup table” for cloud radiative properties– Spectral transmittance and reflectance for ice and liquid clouds interpolated from multi-dimensional look-up table based on DISORT multiple scattering calculations for the (wavenumber range 500 – 2500 cm-1, zenith angle 0 – 80 deg., Deff (Ice: 10 – 157 um, Liquid: 2 – 100 um), OD(vis) (Ice: 0.04 - 100, Liquid 0.06 – 150)
• Compute EOFs and Regressions from cloudy radiance data base– Regress cloud properties (i.e., p, , re) and profile against Radiance EOFs
– For small optical depth, output entire profile– For large optical depth, output profile above the cloud level
Heymsfield, A. J., S. Matrosov, and B. A. Baum: Ice water path-optical depth relationships for cirrus and precipitating cloud layers. J. Appl. Meteor. October 2003
December 5, 2003
MHX MHX
ConclusionsConclusions• The GIFTS hyperspectral measurement concept for observing temperature, water vapor flux, and wind profiles has a solid theoretical and airborne validated foundation.
• Clouds should not severely limit the utility of the GIFTS measurement concept
• The next generation operational GOES-R sounding system is benefiting from the scientific research and technology development conducted under the GIFTS program
• Although the completion of a space qualified GIFTS instrument for space validation of the GIFTS measurement concept awaits funding from a space flight geostationary satellite mission opportunity, the research and development will continue in support of the world’s next generation global observing system.