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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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

•