Licht-im-Terrarium: Literaturdatenbank
Licht-im-Terrarium: Literaturdatenbank |
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Bais, A. F., Gardiner, B. G., Slaper, H., Blumthaler, M., Bernhard, G., & McKenzie, R. L., et al. (2001). Suspen intercomparison of ultraviolet spectroradiometers. Journal of Geophysical Research, 106(D12), 12509–12525. Added by: Sarina (2012-03-30 16:52:20) |
| Resource type: Journal Article DOI: 10.1029/2000JD900561 BibTeX citation key: Bais2001 View all bibliographic details  |
Categories: Englisch = English Creators: Bais, Bernhard, Blumthaler, Brogniez, Eriksen, Gardiner, Gillotay, Gröbner, Josefsson, Kazadzis, Kerr, Kirsch, Kjeldstad, Koskela, Kuik, Leszczynski, McKenzie, Redondasm, Reinen, Seckmeyer, Slaper, Svenoe, Wardle, Webb, Weihs Collection: Journal of Geophysical Research |
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| Abstract |
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Results from an intercomparison campaign of ultraviolet spectroradiometers that was organized at Nea Michaniona, Greece July, 1–13 1997, are presented. Nineteen instrument systems from 15 different countries took part and provided spectra of global solar UV irradiance for two consecutive days from sunrise to sunset every half hour. No data exchange was allowed between participants in order to achieve absolutely independent results among the instruments. The data analysis procedure included the determination of wavelength shifts and the application of suitable corrections to the measured spectra, their standardization to common spectral resolution of 1 nm full width at half maximum and the application of cosine corrections. Reference spectra were calculated for each observational time, derived for a set of instruments which were objectively selected and used as comparison norms for the assessment of the relative agreement among the various instruments. With regard to the absolute irradiance measurements, the range of the deviations from the reference for all spectra was within ±20%. About half of the instruments agreed to within ±5%, while only three fell outside the ±10% agreement limit. As for the accuracy of the wave-length registration of the recorded spectra, for most of the spectroradiometers (14) the calculated wavelength shifts were smaller than 0.2 nm. The overall outcome of the campaign was very encouraging, as it was proven that the agreement among the majority of the instruments was good and comparable to the commonly accepted uncertainties of spectral UV measurements. In addition, many of the instruments provided consistent results relative to at least the previous two intercomparison campaigns, held in 1995 in Ispra, Italy and in 1993 in Garmisch-Partenkirchen, Germany. As a result of this series of intercomparison campaigns, several of the currently operating spectroradiometers operating may be regarded as a core group of instruments, which with the employment of proper operational procedures are capable of providing quality spectral solar UV measurements.
Added by: Sarina |
| Musings |
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Monitoring of solar ultraviolet (UV) radiation is one of the most important activities to have been stimulated in recent years by the observed decreases in stratospheric ozone. It followsn aturallyf rom the inverser elationshipb etweenp hoton energy and wavelength that the chemical and biological effects of ultraviolet radiation are generally very dependent on wavelength. It is therefore essential to obtain spectrally resolved measurements when monitoring ultraviolet irradiance. Spectral ultraviolet irradiance is a difficult parameter to monitor for several reasons: first it involves not one but many measurements over a wide dynamic range, in order to cover the required wavelength range with sufficient spectral resolution; second, the spectral requirement is confounded by the Fraunhofer structure of the solar extraterrestrial spectrum, which displays large fluctuations on a finer spectral scale than can be resolved by the slit functions of the spectrometers currently in use; and third, the radiation arrives from all parts of the sky, to be collected by a receiver of finite area, which must faithfully deliver the incoming photons to the spectrometer proportionally to the cosine of the incidence angle. But the aspect that sets irradiance measurements apart and presents the most intractable obstacle to progress is the inherent difficulty of transferring the absolute scale of spectral irradiance from a national standards laboratory to a field instrument or even from one laboratory to another. Instruments: Bentham DM 150 (3x), Bentham DTM 300 (3x), Biospherical SUV-150, Brewer MkII, Brewer MkIII (6x), Dilor XY, Jobin Yvon HD 10, Metcon CVI CM 112, Optronic 752, Optronic 754 Added by: Sarina (2012-04-03 17:37:56) |