Angular correction of sea surface temperature observed by thermal infrared radiometer

Sugihara, Shuji; Ishiyama, Takashi; Yoshimura, T.

doi:10.1080/01431169308953960

Cited by 2 publications

(3 citation statements)

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“…We also measured temperature of the play pool with and without the generation of O(1 cm) surface waves and observed only small (< 1 °C) effects. Sugihara et al (1993) obtained good corrections for observation angle without invoking surface wave effects.…”

Section: Assessmentmentioning

confidence: 99%

“…Absorbance by the atmosphere over the imaging path would create a negative bias on temperature. However, Sugihara et al (1993) found that errors in temperature due to path attenuation were not significant in their field experiments, except perhaps at very large angles (> 70 degrees).…”

Section: Assessmentmentioning

confidence: 99%

“…Eagleson (1970) indicated that reflectivity of a water surface under clear sky conditions is satisfactorily described by Fresnel's formula. Sugihara et al (1993) measured surface temperature of Uchiura Bay using oblique views from a land-mounted thermal IR radiometer operating in the 7 to 9 µm range and were able to obtain good fits to temperatures measured from a ship after applying corrections for emissivity and reflectance based on Fresnel's formula.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of submarine groundwater discharge by handheld aerial infrared imagery: case study of Kaloko fishpond and bay, Hawai'i

Duarte

Hemond

Frankel

et al. 2006

Limnol. Oceanogr. Methods

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Handheld aerial infrared imagery was used to infer submarine groundwater discharge (SGD) to a Hawaiian fishpond and adjacent bay at Kaloko, Hawai'i, using heat as a tracer for the relatively cooler groundwater. Use of a handheld infrared camera aboard readily available, unmodified aircraft is a convenient and less expensive alternative to use of a camera mounted in the belly of a customized aircraft, although it favors taking images with an oblique view instead of the preferable nadir view. Pond-wide patterns of SGD were readily apparent in oblique images and were typically more apparent in infrared imagery than in ground truth data, due to the formation of thin (order of cm) surface strata of groundwater which could easily fail to be observed with conventional temperature probes. Absolute temperature measurement is affected by the variation of surface emissivity and reflectivity with angle of camera view; corrections based on use of Fresnel's equation were of the order of several degrees centigrade at convenient oblique aerial viewing angles. Other factors that may affect apparent water temperature include sky temperature and camera error. Surface waves may also account for variations in average surface emissivity and reflectance that were not accounted for by the aforementioned corrections. Under suitable conditions, handheld aerial infrared imagery revealed spatial patterns of groundwater inflow, detected differences in water temperature at the meter scale, and measured absolute water temperature with accuracy on the order of 2 to 3 °C.

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Section: Assessmentmentioning

confidence: 99%

Section: Assessmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Assessment of submarine groundwater discharge by handheld aerial infrared imagery: case study of Kaloko fishpond and bay, Hawai'i

Duarte

Hemond

Frankel

et al. 2006

Limnol. Oceanogr. Methods

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The impact of polarization on infrared sea-surface temperature sensing

Shaw¹

1998

IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings.

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One of the most strongly polarized natural infrared sources is the sea surface, yet polarization is rarely considered in infrared radiometric sea-surface temperature sensing. For an off-nadir incidence angle, sea-surface emission is vertically polarized, and reflected atmospheric radiance is horizontally polarized. The net degree of polarization is determined by the relative magnitudes of reflected and surface-emitted radiances, which actually tend to offset one another because of their orthogonal orientations. The significance of partially polarized radiances on radiometric sea-surface temperature measurements is determined primarily by the viewing angle and the inherent polarization sensitivity of the radiometer. This paper discusses several ways that polarization can affect infrared radiometric measurements of sea-surface temperature. A specific example is shown, wherein the polarization sensitivity of a Fourier transform infrared (FTIR) spectrometer results in small errors that are significant for high-accuracy radiometry.

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Angular correction of sea surface temperature observed by thermal infrared radiometer

Cited by 2 publications

References 1 publication

Assessment of submarine groundwater discharge by handheld aerial infrared imagery: case study of Kaloko fishpond and bay, Hawai'i

Assessment of submarine groundwater discharge by handheld aerial infrared imagery: case study of Kaloko fishpond and bay, Hawai'i

The impact of polarization on infrared sea-surface temperature sensing

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