Download - NRC Decadal Survey HyspIRI
20 August 2008
20 August 2008
NRC Decadal Survey HyspIRI Visible ShortWave InfraRed (VSWIR) Imaging Spectrometer
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Multispectral Thermal InfraRed (TIR) Scanner
VSWIR: Plant Physiology and Function Types (PPFT)
Multispectral TIR Scanner
Red tide algal bloom in Monterey Bay, CA
Map of dominant tree species, Bartlett Forest, NH
Charts by JPL/Rob Green & Simon Hook
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20 August 2008
HyspIRI Decadal Survey Mission
In its Decadal Survey Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, the National Research Council of the National Academies recommended a satellite mission to produce global observations of multiple Earth surface attributes for a variety of terrestrial and aquatic studies, the management of terrestrial and coastal natural resources, and forecasting ecological changes and natural hazards.
Currently known as HyspIRI, this mission is in the conceptual design phase at NASA. It consists of an imaging spectrometer in the visible to shortwave infrared regions of the electromagnetic spectrum and a multispectral imager in the thermal infrared portion of the electromagnetic spectrum.
The following charts give an overview of the current baseline HyspIRI science questions and science measurements
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HyspIRI Mission Overview
Ecosystem and Surface Science
To measure and understand: The composition, function, and health of land and water ecosystems? How are these ecosystems being altered by human activities and natural causes? How do these changes affect fundamental ecosystem processes upon which life on Earth depends?
To measure the surface temperature and emissivity of the Earth and how these parameters respond to natural and human-induced changes at the local, regional and global scale.
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HyspIRI Mission Overview
Urgency for HyspIRI
Three fundamental components required for understanding ecosystems are: function, composition, and structure. This mission for the first time provides global measurements of ecosystem function with vastly improved measures of composition including biodiversity.
This mission also provides the surface temperature and emissivity of the Earth at high spatial and high temporal resolution that will be used to address key science questions in five research areas: volcanoes, wildfires, water use and availability, urbanization, land surface composition and change.
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HyspIRI Mission Overview
HyspIRI Key Science Questions
What are the spatial distributions of different plant functional groups, diagnostic species, and ecosystems? How do changes in the physical, chemical, and biotic environment affect the productivity, carbon storage and biogeochemical cycling processes of ecosystems? How do human-caused and natural disturbances affect the distribution, biodiversity and functioning of ecosystems? How do changes in ecosystem composition and function affect human health, resource use, and resource management?
What are the changes in the behavior of active volcanoes? What is the impact of global biomass burning on the terrestrial biosphere and atmosphere? How can we better characterize trends in local and regional water use? How does urbanization affect the environment? What is the composition and temperature of the exposed surface of the Earth?
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HyspIRI Imaging Spectroscopy Science Measurements
Science Questions:
• What is the composition, function, and health of land and water ecosystems?
• How are these ecosystems being altered by human activities and natural causes?
• How do these changes affect fundamental ecosystem processes upon which life on Earth depends?
Red tide algal bloom in Monterey Bay, CA
Map of dominant tree species, Bartlett Forest, NH
Imaging spectrometer: 87kg / 38W
Schedule: 4 year phase A-D, 3 years operations
All components have flown in space
Measurement:
• 380 to 2500 nm in 10nm bands
• Accurate 60 m resolution
• 19 days revisit
• Global land and shallow water
Aquatic Terrestrial
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HyspIRI VSWIR Science Measurements
• Measure the global land and coastal/shallow water (> -50m).
• 19 day equatorial revisit to generate seasonal and annual products.
Spatial 1000 m
• Measure the molecular absorption and constituent scattering signatures in the spectral range from 380 to 2500 nm at 10 nm, and at 60 m spatial sampling.
PPFT at 60 m
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SpectralRange 380 to 2500 nm in the solar reflected spectrumSampling <= 10 nm {uniform over range}Response <= 10 nm (full-width-at-half-maximum) {uniform over range}Accuracy <0.5 nm
RadiometricRange & Sampling 0 to 1.5 X max benchmark radiance, 14 bits measuredAccuracy >95% absolute radiometric, 98% on-orbit reflectance, 99.5% stabilityPrecision (SNR) See spectral plots at benchmark radiancesLinearity >99% characterized to 0.1 %Polarization <2% sensitivity, characterized to 0.5 %Scattered Light <1:200 characterized to 0.1%
SpatialRange >150 km (12 degrees at 700 km altitude)Cross-Track Samples >2500Sampling <=60 mResponse <=60 m sampling (FWHM)
UniformitySpectral Cross-Track >95% cross-track uniformity {<0.5 nm min-max over swath}Spectral-IFOV-Variation >95% spectral IFOV uniformity {<5% variation over spectral range}
HyspIRI VSWIRScience Measurement Characteristics
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TemporalOrbit Crossing 11 am sun synchronous descendingGlobal Land Coast Repeat 19 days at equatorRapid Response Revisit 3 days (cross-track pointing)
Sunglint AvoidanceCross Track Pointing 4 degrees in backscatter direction
OnOrbit CalibrationLunar View 1 per month {radiometric}Solar Cover Views 1 per week {radiometric}Surface Cal Experiments 3 per year {spectral & radiometric}
Data CollectionLand Coverage Land surface above sea level excluding ice sheetsWater Coverage Coastal zone -50 m and shallowerSolar Elevation 20 degrees or greaterOpen Ocean Averaged to 1km spatial samplingCompression >=3.0 lossless
HyspIRI VSWIR Science Measurements
Characteristics
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HyspIRI VSWIR Science MeasurementsKey SNR and Uniformity Requirements
Wavelength
Cross Track Sample
Depiction-Grids are the detectors-dots are the IFOV centers-Colors are the wavelengths
RequirementSpectral Cross-Track >95% cross-track uniformity {<0.5 nm min-max over swath}
Spectral-IFOV-Variation >95% spectral IFOV uniformity {<5% variation over spectral range}
Benchmark Radiances
Uniformity Requirement
Required SNR
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HyspIRI Thermal Infrared Science Measurements
• Measure the land surface temperature and emissivity
• 5 day equatorial revisit to generate monthly, seasonal and annual products.
• 60 m spatial resolution
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Wavelength (um)
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H1 (m21)H2 (m28)H3 (a10)H4 (a11)H5 (a12)H6H7H8 (m32)
• 7 bands between 7.5-12 µm and 1 band between 3-5 µm
• 3-5 µm band saturates at 1400K
• 7.5-12 µm bands saturate at 400K
TIR at 45 m
1000 m
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HyspIRI TIR Science MeasurementsSummary Measurement Characteristics
Spectral
Bands (8) 3.98, 7.35, 8.28, 8.63, 9.07, 10.53, 11.33, 12.05 (µm)
Bandwidth 0.084, 0.32, 0.34, 0.35, 0.36, 0.54, 0.54, 0.52 (µm)
Accuracy <0.01 µm
Radiometric
Range Bands 2-8= 200K – 400K; Band 1= 1400K
Resolution < 0.05 K, Linear Quantization to 14 bits
Accuracy < 0.5 K 3-sigma at 250K
Precision (NEdT) < 0.2K
Linearity >99% characterized to 0.1 %
Spatial
IFOV 60 m
MTF >0.2 at FNy
Scan Type Whiskbroom
Swath Width 600 km (±25.5° at 623 km altitude)
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TemporalOrbit Crossing 11 am sun synchronous descendingGlobal Land Repeat 5 days at equator
OnOrbit CalibrationLunar View 1 per month {radiometric}Blackbody Views 1 per scan {radiometric}Surface Cal Experiments 1 per month {radiometric}Spectral Surface Cal Experiments 1 per year
Data CollectionLand Coverage Land surface above sea level Day/Night
Always-onDownlink Stations Svalbard and Fairbanks
TIR Science Measurements Characteristics Continued
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2008 HyspIRI Workshop
NASA will convene a science community workshop on October 21-23, 2008, in Monrovia, CA. The primary goal of this workshop will be to discuss and review a draft white paper containing the scientific rationale for the HyspIRI mission. This white paper will focus on: the scientific questions the HyspIRI mission will address: the objectives of the mission; potential mission products; and resulting mission requirements.
Workshop plenary discussions will provide an initial overview of the rationale for the mission, addressing the topics listed above. Breakout sessions will allow for community discussion and comment on these topics as well as other topics not covered by the white paper, including the need for additional studies and preparatory work.
We will summarize workshop proceedings and findings in a report that will set the stage for finalizing the white paper. This white paper will provide guidance to NASA as it proceeds with Phase A mission planning.
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HyspIRI Launch Vehicle Compatability
1.5 m