Infrared radiance of the wind-ruffled sea

Zeisse, C. R.; McGrath, Charles P.; Littfin, Kathleen M.; Hughes, H. G.

doi:10.1364/josaa.16.001439

Cited by 29 publications

(13 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Contributions to instant ocean radiance received by CAR aboard an aircraft scanning the d a c e from a height H meters above as the aircraft traces a clockwise cirdar flight track for measuring surface bidirectional reflectance from ~d i r to the horizon, as well as much of the transmittance from near zenith to the horizon. The inset (modified after Zeiss et al 1999) shows the geometry of facet reflection with unit vectors Us and U, pointing toward the Sun and the sensor, respectively, from the origin of a right-handed coordinate system located at the reflection point. cloud-free cases with various conditions.…”

Section: S U M M a R Y And Conclusionmentioning

confidence: 99%

Airborne Spectral Measurements of Ocean Directional Reflectance

Gatebe

County

King

et al. 2005

Journal of the Atmospheric Sciences

View full text Add to dashboard Cite

The Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair 580 (CV-580) research aircraft during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) field campaign and obtained measurements of bidirectional reflectance distribution function (BRDF) of the ocean in July and August 2001 under different illumination conditions with solar zenith angles ranging from 15° to 46°. The BRDF measurements were accompanied by concurrent measurements of atmospheric aerosol optical thickness and column water vapor above the airplane. The method of spherical harmonics with Cox–Munk wave-slope distribution is used in a new algorithm developed for this study to solve the atmosphere–ocean radiative transfer problem and to remove the effects of the atmosphere from airborne measurements. The algorithm retrieves simultaneously the wind speed and full ocean BRDF (sun’s glitter and water-leaving radiance) from CAR measurements and evaluates total albedo and equivalent albedo for the water-leaving radiance outside the glitter. Results show good overall agreement with other measurements and theoretical simulations, with the anisotropy of the water-leaving radiance clearly seen. However, the water-leaving radiance does not show a strong dependence on solar zenith angle as suggested by some theoretical studies. The spectral albedo was found to vary from 4.1%–5.1% at λ = 0.472 μm to 2.4%–3.5% for λ ≥ 0.682 μm. The equivalent water-leaving albedo ranges from 1.0%–2.4% at λ = 0.472 μm to 0.1%–0.6% for λ = 0.682 μm and 0.1%–0.3% for λ = 0.870 μm. Results of the validation of the Cox–Munk model under the conditions measured show that although the model reproduces the shape of sun’s glitter on average with an accuracy of better than 30%, it underestimates the center of the sun’s glitter reflectance by about 30% for low wind speeds (<2–3 m s−1). In cases of high wind speed, the model with Gram–Charlier expansion seems to provide the best fit.

show abstract

Section: S U M M a R Y And Conclusionmentioning

confidence: 99%

Airborne Spectral Measurements of Ocean Directional Reflectance

Gatebe

County

King

et al. 2005

Journal of the Atmospheric Sciences

View full text Add to dashboard Cite

show abstract

“…In each micro-facet, water is considered to be specular and reflection process follows the Fresnel law [12][13][14]. Micro-facets of wave surface have different slopes and directions [10,11].…”

Section: Polarization Ray Tracingmentioning

confidence: 99%

Performance of eliminating sun glints reflected off wave surface by polarization filtering under influence of waves

Guocong

Wang

Zhang

et al. 2016

Optik

View full text Add to dashboard Cite

“…The image enhancement of low attitude sea surface environments in a medium-wave infrared band is a challenging research subject because the radiation from sea surface depends on sea clutter, sun glints and atmosphere [1] . Owing to the mirror reflections from the wave facets, low contrast and the thermodynamic state of ship targets affect the detection and visualization of ship targets in the low attitude sea surface scene.…”

Section: Introductionmentioning

confidence: 99%

Adaptive enhancement of sea surface targets in infrared high dynamic range image

Dong

Lin

2015

SPIE Proceedings

View full text Add to dashboard Cite

A high dynamic range infrared image of the sea surface scene includes the effects due to the sea clutter, mirror reflections from the wave facets, which decrease the visibility of the ship targets and their details. This paper provides an efficient adaptive enhancement technique for ship targets based on bilateral filtering and visual saliency detection. The 14-bit raw image is separated into a detail layer and a base layer by applying an adaptive bilateral filter. Then the two layers are processed separately and added afterward. Hereafter by employing visual saliency detection we can get the gain matrix to improve the contrast of ship targets. Finally, the image whose contrast is improved is quantized to the display range. The strength of our proposed method lies in its ability to inhibit the sea clutter and adaptability in different sea surface scene and shows a better performance in the contrast of the ship targets and the visibility of their details.

show abstract

Infrared radiance of the wind-ruffled sea

Cited by 29 publications

References 13 publications

Airborne Spectral Measurements of Ocean Directional Reflectance

Airborne Spectral Measurements of Ocean Directional Reflectance

Performance of eliminating sun glints reflected off wave surface by polarization filtering under influence of waves

Adaptive enhancement of sea surface targets in infrared high dynamic range image

Contact Info

Product

Resources

About