land surface monitoring from the moon
TRANSCRIPT
Land Surface Monitoring fromthe Moon
Jack Mustard, Brown UniversityWorkshop on Science Associated with Lunar
Exploration Architecture
Unique Perspective of LunarObservation Platform
• Low Earth Orbit:– sun synchronous
• Geostationary:– same hemisphere of the Earth– Fixed emergence, changing incidence angle
• Lunar– rotating planet with changing incidence and
emergence angles (phases)– 28 day repeat of illumination conditions
Priorities of NRC Decadal Survey forLand-Use Change, Ecosystem
Dynamics and Biodiversity
2-day globalcoverage
1 kmGlobalHyperspectralWater colorGlobal OceanProductivity
Multiple daily250 mWesternHemisphere
HyperspectralWater colorCoastalEcosystems
Diurnal,assimilatedevery 24 hrs
100 m stripsGlobalActive LIDARCO2 mixingratio, COconcentrations
CarbonBudget
Monthly50-150 mGlobalLIDAR, RadarVegetationheight,structure
Ecosystemstructure andbiomass
30 day,pointable
50-75 mGlobal,pointable
HyperspectralVegetationproperties(species,NPP,disturbance)Coral Reefhealth
EcosystemFunction
FrequencySpatialresolution
CoverageSensorVariablesMission
Land Surface MonitoringBRDF from MODIS Sensors
• Global mapping of surface albedo measures– Parameterize global climate and
biogeochemical models– Initializing numerical weather prediction
and mesoscale models– Quantifying the surface background for
cloud studies• “Correction” of observations for directional
effects– Nadir BRDF-Adjusted Reflectance (NBAR)
standardizes reflectance to a specific viewand illumination geometry—noon sun, nadirview
• Characterization of surface scattering behavior– Non-Lambertian surface BRDF effects– Quantifying the surface anisotropy
White-Sky Spectral White-Sky Spectral AlbedoAlbedo7 - 22 April, 20027 - 22 April, 2002
NIR (0.1-0.4) Red (0.0-0.16) Blue (0.0-0.18)Schaaf et. al. 2006
Land Surface MonitoringRecommendations from ESS Decadal
Survey• Considered the value of multi-angle remote
sensing– Capable of retrieving certain ecosystem
properties such as ecosystem structure• Did not consider it a high priority, and could
be accommodated with existing multi-anglesensors (e.g. MISR)
• But, would be a valuable complement andrecommend continued study of the science tobe derived from multiangle observations
• Lunar Observatory would provide a uniqueperspective and would more completelysample the BRDF for science applications(e.g. near 0 phase (hot spot)
Land Surface Monitoring
• Phenology– Timing and magnitude of ecosystem processes
indicated by greenness measured as a function oftime
– Integration of this signal a measure of primary andnet productivity
– Interannual variability coupled to climate changeover northern latitudes
– Higher precision in timing or to time events wouldbe beneficial to environmental monitoring
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ND
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Dif
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Veg
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Date
AVHRRNDVI May 2000
MODISNDVI May 2000
Measuring Phenology
165June 15th
110April 20th
Onset
Landsat Onset(color scale has changed)
MODIS Onset
A
Fisher and Mustard, 2006
HyperspectralHyperspectalsensors bring newecosystemmeasurementcapability
Spatial resolutionof 500 m- 1 kmpossible with a 1 mtelescope
MODISMS Capability
HyperspectralCapability
Drought Stress and Carbon Uptake with HyperionAsner et al., PNAS, 2006
Coastal Ocean Monitoring
• Coastal Ocean requires high SNR, hightemporal frequency, and ability to reach intothe UV (350 nm)
• NRC Recommends a geosynchronoushyperspectral sensor to capture events,increase signal to noise, and obtain cloud-free observations
• A lunar hyperspectral sensor would fulfillsome of these requirements but spatialresolution would be a challenge
Land Surface Monitoring
• Cross-calibration of instruments• Long-term measurements• Bidirectional Reflectance Distribution
Function (BRDF)• Tracking events• Compliment LEO and GEO
observations
Challenges for Earth Observation
• Lunar outpost not optimum for Earthobservation (frequency of Earth in fieldof view)
• For systematic measurement changingviewing conditions present a challenge
•