CALMIT Field Program Center for Advanced Land Management Information Technologies (CALMIT) University of Nebraska Lincoln
Field Program: Three Areas Agriculture Surface Waters Coastal / Marine
1) Agriculture Biophysical Measurements: Vegetation Fraction Leaf Area Pigment Type and Density Leaf-Water Content Primary Productivity / Biomass Absorbed Photosynthetically Active Radiation
CALMIT Field Facility Note aircraft-calibration targets on concrete strip (above)
Goliath
Goliath Specifications All terrain (tracked wheels) Boom height = 10.5m (with full rotation) Boom length = 3.8m stowed; 12m extended Platform height = approx. 2m Platform width = 2.6 x 3m Passengers = driver + 4 Wheel spacing for standard 76.2 cm (30- inch) rows
Goliath is Mobile
Spectroradiometers Available on Goliath Dual Spectron SE-590 s Dual Ocean Optics USB-2000 s ASD-FR
Spectroradiometers Spectron SE-590 (2) 256 channels; 365-1114 nm
Spectroradiometers ASD Field Spec - FR (2) 2150 channels; 350-2500 nm
Spectroradiometers Ocean Optics USB2000 (4) 2048 Channels, 350-1000 nm Dual systems allow simultaneous capture of downwelling (sky) irradiance and upwelling (target) radiance
Dual Fibers Facilitate Data Collection Under Rapidly Changing Illumination Conditions
Other Sensors on Goliath Canon digital-video camera Linear Laboratories infrared thermometer P-band Radar Scatterometer
Vegetation Fraction: Digital Camera V8 (19 June) V12 (6 July) R2 (28 July) R5 (20 August)
Early Season 30 May 28, 2000. 25 104-1_194N-S 104-2_194N-S 20 104-3_194N-S 15 104-4_194N-S 10 104-5_194N- S 5 0 350 450 550 650 750 850 950 1050 1150 Wavelength (nm)
Mid-Season 60 July 21, 2000. 50 304-1_194N-S 304-2_194N-S 40 304-3_194N-S 304-4_194N-S 30 20 10 0 350 450 550 650 750 850 950 1050 1150 Wavelength (nm)
Late Season 50 40 August 18, 2000. 204-1_194N-S 204-2_194N-S 30 204-3_194N-S 20 204-4_194N-S 10 0 350 450 550 650 750 850 950 1050 1150 Wavelength (nm)
Estimating Vegetation Fraction 0.6 Vegetation Fraction-Estimated 0.5 0.4 0.3 0.2 0.1 0.0-0.1-0.2 VARI R 2 = 0.9016-0.3 0 1 0 20 30 40 50 60 70 80 Vegetation Fraction-Measured
Other Systems on Goliath Real-time DGPS Wireless Internet
Other Field Instruments UniSpec 256 Channels, 300-1100 nm Leaf Clip Operates with internal light source
University of Nebraska Carbon Sequestration Program Project Study Teams: Micrometeorological (CO 2 and H 2 O Vapor Fluxes) Soil Water Balance Soil C Plant C Assimilation NO 2 and CH 4 Flux Leaf Level Remote Sensing Canopy Level Remote Sensing Technology Design & Adoption
Seasonal VARI 0.7 0.6 0.5 0.4 Irrigated and Non-Irrigated Corn June 6 through September 24 2001 Irrigated Corn VARI 0.3 0.2 0.1 0.0-0.1 Non-Irrigated Corn -0.2-0.3 05/29/0106/18/0107/08/0107/28/0108/17/0109/06/0109/26/0110/16/01 Date
Why Use Goliath? Reflectance, % 8 6 4 2 July 3, 2001 - Carbon 3 Measurements from Goliath Platform 0 400 450 500 550 600 650 700
Why Use Goliath? 8 6 July 3, 2001. Carbon-3. Handheld measurements 4 2 0 400 450 500 550 600 650 700
Hercules (2003 Field Season)
2) Surface Waters: Mesocosms
Surface Waters: Macrocosms
Underwater Light Fields
Okoboji Lakes (20 Sep 01) Reflectance, % 3.5 3.0 2.5 2.0 17 mg/m 3 1.5 12 1.0 0.5 7 0.0 400 500 600 700 800 900 Reflectance, % 4.0 58 mg/m 3 3.5 3.0 2.5 42 2.0 1.5 27 1.0 0.5 0.0 400 450 500 550 600 650 700 750 800 Wavelength, nm Wavelength, nm West Okoboji East Okoboji
Examples of Ancillary Data Sechi Disk Pigments» Chlorophyll» Carotenoids» Phycocyanin Phytoplankton Densities Turbidity Non-Organic Solids
Classified AISA Image
Coastal / Marine Roatan Island, Honduras
The Bob Technology
Remote Sensing of Corals
Video of Coral Features Scanned
Coral Spectra 100 SELECTED CLOSE RANGE SPECTRA ROATAN ISLAND, HONDURAS PERCENT REFLECTANCE 80 60 40 20 1 - Montastrea annularis 2 - Porites asteroides 3 - Acropora palmata 4 - Millepora complanta 5 - SAND BOTTTOM 5 1 2 3 4 0 400 450 500 550 600 WAVELENGTH (nm) 650 700
Traditional Calibration
Dual Fibers Collecting spectra on a coral reef: Roatan Island, Honduras (March, 2002)
Using Dual Spectoradiometers for Hyperspectral Data Collection Land Lakes Underwater
Advantage Allows for data collection under most irradiance conditions Method is not valid if the irradiance changes during the scan time of the instruments (Usually 5 to 20 sec)
Hardware Requirements Two similar spectroradiometers
Hardware Requirements Two similar spectroradiometers Hemispherical cosine corrected optic
Hardware Requirements Two similar spectroradiometers Hemispherical cosine corrected optic Cables, power supplies, fibers, etc.
Hardware Requirements Two similar spectroradiometers Hemispherical cosine corrected optic Cables, power supplies, fibers, etc. Calibrated reflectance standard
Computer Additional Requirements
Additional Requirements Computer Spectral calibration of instruments
Additional Requirements Computer Spectral calibration of instruments Software for acquisition & processing
Additional Requirements Computer Spectral calibration of instruments Software for acquisition & processing Radiometric calibration optional Not necessary for reflectance Needed for radiance/irradiance
Method Near simultaneous data acquisition from both instruments Downwelling and upwelling radiation Instruments have different integration times
Method Near simultaneous data acquisition from both instruments Downwelling and upwelling radiation Instruments have different integration times Spectral channels of downwelling instrument interpolated To match channels of upwelling instrument
Method Near simultaneous data acquisition from both instruments Downwelling and upwelling radiation Instruments have different integration times Spectral channels of downwelling instrument interpolated To match channels of upwelling instrument Ratio of upwelling divided by downwelling is calculated
Method Near simultaneous data acquisition from both instruments Downwelling and upwelling radiation Instruments have different integration times Spectral channels of downwelling instrument interpolated To match channels of upwelling instrument Ratio of upwelling divided by downwelling is calculated Use scans of calibration panel to correct all other scans Panel reflectance is known A correction factor (CF) is calculated for each channel CF applied to upwelling/downwelling ratio of each scan
Corn & Soybeans May 21, 2002 120 100 % Reflectance 80 60 40 20 0 350 450 550 650 750 850 950 Wavelength (nm) Allows calibration scans to be compared
Corn & Soybeans June 21, 2002 120 100 % Reflectance 80 60 40 20 0 350 450 550 650 750 850 950 Wavelength (nm) Correction factors calculated for each channel based on the median value of the calibration scans for that channel
Corn & Soybeans July 23, 2002 120 100 % Reflectance 80 60 40 20 0 350 450 550 650 750 850 950 Wavelength (nm) Correction factors applied to all scans
UNL Field-Radar System (EE Dept.)
Radar Measurements of Wetlands
Radar in the Field: Wetlands
Field Program: One Part of System
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