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Ocean Color Inferred from Radiometers on Low-Flying Aircraft

View Article: PubMed Central - PubMed

ABSTRACT

The color of sunlight reflected from the ocean to orbiting visible radiometers has provided a great deal of information about the global ocean, after suitable corrections are made for atmospheric effects. Similar ocean-color measurements can be made from a low-flying aircraft to get higher spatial resolution and to obtain measurements under clouds. A different set of corrections is required in this case, and we describe algorithms to correct for clouds and sea-surface effects. An example is presented and errors in the corrections discussed.

No MeSH data available.


Related in: MedlinePlus

Relative radiance weighting W of a point on the bottom of a cloud as a function of the horizontal distance from the receiver to that point d over the cloud base height hC for the actual radiance reflected off the surface (blue) and the estimate from the measured irradiance (red). The upper and lower red curves correspond to an aircraft flight altitude of 0.25hC and 0.5hC, respectively. The upper and lower blue curves correspond to root-mean-square surface slopes of 0.3 (wind about 20 m s-1) and 0.2 (wind about 9 m s-1), respectively.
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f9-sensors-08-00860: Relative radiance weighting W of a point on the bottom of a cloud as a function of the horizontal distance from the receiver to that point d over the cloud base height hC for the actual radiance reflected off the surface (blue) and the estimate from the measured irradiance (red). The upper and lower red curves correspond to an aircraft flight altitude of 0.25hC and 0.5hC, respectively. The upper and lower blue curves correspond to root-mean-square surface slopes of 0.3 (wind about 20 m s-1) and 0.2 (wind about 9 m s-1), respectively.

Mentions: The models for foam coverage also represent data with a wide range of values. Consider, for example, figure 9 of Monahan and O'Muircheartaigh [17]. At a wind speed of 10 m s-1, the measured P(FOAM) values range from about 0.005 to about 0.05. For the value at the low end of this range, a correction using Eq. (12) would be too high by 3.3×10-4 sr -1; for the value at the high end, the correction would be too low by 0.0035.


Ocean Color Inferred from Radiometers on Low-Flying Aircraft
Relative radiance weighting W of a point on the bottom of a cloud as a function of the horizontal distance from the receiver to that point d over the cloud base height hC for the actual radiance reflected off the surface (blue) and the estimate from the measured irradiance (red). The upper and lower red curves correspond to an aircraft flight altitude of 0.25hC and 0.5hC, respectively. The upper and lower blue curves correspond to root-mean-square surface slopes of 0.3 (wind about 20 m s-1) and 0.2 (wind about 9 m s-1), respectively.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3927510&req=5

f9-sensors-08-00860: Relative radiance weighting W of a point on the bottom of a cloud as a function of the horizontal distance from the receiver to that point d over the cloud base height hC for the actual radiance reflected off the surface (blue) and the estimate from the measured irradiance (red). The upper and lower red curves correspond to an aircraft flight altitude of 0.25hC and 0.5hC, respectively. The upper and lower blue curves correspond to root-mean-square surface slopes of 0.3 (wind about 20 m s-1) and 0.2 (wind about 9 m s-1), respectively.
Mentions: The models for foam coverage also represent data with a wide range of values. Consider, for example, figure 9 of Monahan and O'Muircheartaigh [17]. At a wind speed of 10 m s-1, the measured P(FOAM) values range from about 0.005 to about 0.05. For the value at the low end of this range, a correction using Eq. (12) would be too high by 3.3×10-4 sr -1; for the value at the high end, the correction would be too low by 0.0035.

View Article: PubMed Central - PubMed

ABSTRACT

The color of sunlight reflected from the ocean to orbiting visible radiometers has provided a great deal of information about the global ocean, after suitable corrections are made for atmospheric effects. Similar ocean-color measurements can be made from a low-flying aircraft to get higher spatial resolution and to obtain measurements under clouds. A different set of corrections is required in this case, and we describe algorithms to correct for clouds and sea-surface effects. An example is presented and errors in the corrections discussed.

No MeSH data available.


Related in: MedlinePlus