Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-2-28
pubmed:abstractText
The problems encountered in the elaboration of measurements of direct and sky diffuse solar irradiance are the following: (1) to carry out the calibration for the direct irradiance, which consists in determining the direct irradiance at the upper limit of the atmosphere; (2) to carry out the calibration for the diffuse irradiance, which consists in determining the solid viewing angle of the sky radiometer; (3) to determine the input parameters, namely, ground albedo, real and imaginary parts of the aerosol refractive index, and aerosol radius range; and (4) to determine from the optical data the columnar aerosol optical depth and volume radius distribution. With experimental data and numerical simulations a procedure is shown that enables one to carry out the two calibrations needed for the sky radiometer, to determine a best estimate of the input parameters, and, finally, to obtain the average features of the atmospheric aerosols. An interesting finding is that inversion of only data of diffuse irradiance yields the same accuracy of result as data of both diffuse and direct irradiance; in this case, only calibration of the solid viewing angle of the sky radiometer is needed, thus shortening the elaboration procedure. Measurements were carried out in the Western Mediterranean Sea (Italy), in Tokyo (Japan), and in Ushuaia (Tierra del Fuego, Argentina); data were elaborated with a new software package, the Skyrad code, based on an efficient radiative transfer scheme.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Feb
pubmed:issn
0003-6935
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
896-907
pubmed:year
1999
pubmed:articleTitle
Calibration and data elaboration procedure for sky irradiance measurements.
pubmed:affiliation
Department of Physics, University of Cagliari, via Ospedale 72, 09124 Cagliari, Italy.
pubmed:publicationType
Journal Article