High temporal and spatial thermal infrared characterization of dense grass during high-humidity conditions

Jerrell R. Ballard Jr.; Thomas E. Berry; David L. Leese; Stacy C. Anderson; Laura S. Bunch

doi:10.1117/12.541388

5 August 2004 High temporal and spatial thermal infrared characterization of dense grass during high-humidity conditions

Jerrell R. Ballard Jr., Thomas E. Berry, David L. Leese, Stacy C. Anderson, Laura S. Bunch

Author Affiliations +

Proceedings Volume 5431, Targets and Backgrounds X: Characterization and Representation; (2004) https://doi.org/10.1117/12.541388
Event: Defense and Security, 2004, Orlando, Florida, United States

Abstract

This paper describes the high temporal (1 sec to 5 min) and spatial thermal infrared directional characterization of low dense grass canopy during high humidity conditions to study the diurnal and spatial variation of simple vegetation background signatures. The instruments used in the characterization effort consisted of two infrared cameras (8-14 μm) set at nadir and 45 degrees, four sets of radiometers (3-5 μm and 8-12 μm), micrometeorological instruments, and thermocouples placed within the grass. Micrometeorological measurements included wind speed, air temperature, and relative humidity observed at several heights above the canopy sampling occurred at 1 sec and 5 min intervals. These measurements were used to calculate wind speed, air temperature, and relative humidity profiles down to the top of the grass canopy. Analysis of the measured thermal images consists of quantifying the diurnal thermal differences in the directional background signatures, directional thermal variance, and thermal variance differences related to observation angle, solar radiation, and wind speed. These preliminary analyses indicate that for this environment, measurements at large temporal scales, the thermal variance is primarily affected by solar radiation, but at small temporal scales turbulent mixing of fluxes becomes the more dominant cause of the variance.

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Jerrell R. Ballard Jr., Thomas E. Berry, David L. Leese, Stacy C. Anderson, and Laura S. Bunch "High temporal and spatial thermal infrared characterization of dense grass during high-humidity conditions", Proc. SPIE 5431, Targets and Backgrounds X: Characterization and Representation, (5 August 2004); https://doi.org/10.1117/12.541388

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