Sky luminance distribution in Central Europe and the Mediterranean area during the winter period

Bartzokas, A.; Darula, Stanislav; Kambezidis, H. D.; Kittler, Richard

doi:10.1016/s1364-6826(02)00283-3

Cited by 37 publications

(30 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…T eff accounts for all radiance losses at the image sensor due to the camera optics, including illumination factors, external and internal reflections, and absorption within the lens. As expected from [6][7][8][9][10][11][12][13], Fig. 4's largest L occur near the zenith.…”

Section: A All-sky Maps Of Overcast Radiancesupporting

confidence: 70%

“…Central to many such models is the assumption that, if shortterm brightness fluctuations [4,5] are excluded, either luminance L v or visible-wavelength radiance L is largest at and symmetric about the zenith in optically thick overcasts [6][7][8][9]. Indeed, several measurement campaigns have produced data that apparently support this assumption [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Observed brightness distributions in overcast skies

Lee

Devan

2008

Appl. Opt.

View full text Add to dashboard Cite

Beneath most overcasts, clouds' motions and rapidly changing optical depths complicate mapping their angular distributions of luminance L v and visible-wavelength radiance L. Fisheye images of overcast skies taken with a radiometer-calibrated digital camera provide a useful new approach to solving this problem. Maps calculated from time-averaged images of individual overcasts not only show their brightness distributions in unprecedented detail, but they also help solve a long-standing puzzle about where brightness maxima of overcasts are actually located. When combined with simulated radiance distributions from MODTRAN4, our measured radiances also let us estimate the gradients of cloud thickness observed in some overcasts.

show abstract

Section: A All-sky Maps Of Overcast Radiancesupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Observed brightness distributions in overcast skies

Lee

Devan

2008

Appl. Opt.

View full text Add to dashboard Cite

show abstract

“…To interpret sky patterns for places where a high solar-altitude dominated (e.g. Hong Kong) can lead to ambiguous results [26]. Recently, Tregenza [27] studied these 15 sky-luminance models using measured sky luminance distributions from four stations, namely Singapore, Fukuoka (Japan), Garston (UK) and Sheffield (UK), which represent tropical humid and temperate maritime climates.…”

Section: Kittler Sky-distribution Model (Kittlersdm)mentioning

confidence: 99%

Study of models for predicting the diffuse irradiance on inclined surfaces

Cheung

2005

Applied Energy

View full text Add to dashboard Cite

“…However, daylight climate can be discussed in three annual periods with characteristic illuminance levels, i.e. winter (November-February), summer (May-August) and the transitional months of March, April, September and October Kittler, 2000, 2001;Bartzokas et al, 2003). The present study is based on instantaneous measurements of illuminance and irradiance data collected at the CIE IDMP station in Bratislava during a 8 year period (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001).…”

Section: Data Collection and Analysismentioning

confidence: 99%

Sunshine duration and daily courses of illuminance in Bratislava

Darula¹,

Kittler²

2004

Intl Journal of Climatology

View full text Add to dashboard Cite

The occurrences of typical sky conditions during overcast days are close to the CIE Overcast Sky Standard in the Bratislava area; their variation is specified by the diffuse coefficient k dd = D v /E v where D v is the horizontal diffuse illuminance and E v is the extraterrestrial illuminance. Luminance distributions on cloudless days are close to the CIE Clear Sky Standard. Complex daylight conditions can be expected during cloudy days when moving clouds cause frequent sun disk shading with abrupt changes in illuminance levels. Since sunshine duration is one of the basic climatic parameters that describes sunny situations, the present study attempts to investigate its relation to daily illuminance levels. However, the average daily value of sunshine duration does not exactly correspond to the same illuminance course, as it depends on the temporal distribution of sunny periods within the day. Anyhow, the estimation of daytime illuminance levels is mainly influenced by the presence or absence of sunshine with frequent sky luminance patterns.

show abstract

Sky luminance distribution in Central Europe and the Mediterranean area during the winter period

Cited by 37 publications

References 6 publications

Observed brightness distributions in overcast skies

Observed brightness distributions in overcast skies

Study of models for predicting the diffuse irradiance on inclined surfaces

Sunshine duration and daily courses of illuminance in Bratislava

Contact Info

Product

Resources

About