HR: 14:25h
AN: H43H-04    [Abstracts]
TI: Surface Energy Flux Estimation Over a Wheat Crop Using Time-Temperature Difference Thermal Infrared Remote Sensing
AU: * French, A N
EM: afrench@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AU: Fitzgerald, G
EM: GFitzgerald@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AU: Hunsaker, D
EM: DHunsaker@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AU: Clarke, T
EM: TClarke@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AU: Luckett, B
EM: BLuckett@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AU: Pinter, P
EM: PPinter@uswcl.ars.ag.gov
AF: USDA/ARS, U.S. Water Conservation Lab 4331 E. Broadway Road, Phoenix, AZ 85040 United States
AB: Estimation of surface energy fluxes using multiple thermal infrared images at different times of day is a remote sensing technique that reduces errors due to detector calibration and uncertain temperature gradients between the land surface and overlying air. By using observed time-temperature changes, rather than the absolute values themselves, bias errors are suppressed. The technique works best when one image set is acquired near dawn since sensible heat flux at this time is small and air temperatures are close to surface temperatures. Using a helicopter-mounted thermal camera, along with a multispectral imaging system, we demonstrate application of the time-temperature difference method over a Maricopa, Arizona research wheat field in 2005. The 1.7 ha field consists of a group of 32 plots designed to assess remote sensing approaches to irrigation scheduling. Image data for this particular experiment were collected on 10 March 2005 at four times between dawn and 13:00 local time. Nominal image resolution was 0.5 m obtained from 760 m above the ground. Surface flux estimates show reasonable agreement with net radiometer data at hourly time scales as well as with available soil moisture data at daily time scales. Based on radiometric temperature comparisons using both aircraft and ground-based detectors, the results also confirm the method's beneficial reduction of detector bias.
DE: 1814 Energy budgets
DE: 1818 Evapotranspiration
DE: 1855 Remote sensing (1640)
SC: Hydrology [H]
MN: Fall Meeting 2005