Quality assurance of the Brewer spectral UV measurements in Finland
The quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calc...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2008-06-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/8/3369/2008/acp-8-3369-2008.pdf |
| _version_ | 1818235312948641792 |
|---|---|
| author | K. Lakkala A. Arola A. Heikkilä J. Kaurola T. Koskela E. Kyrö A. Lindfors O. Meinander A. Tanskanen J. Gröbner G. Hülsen |
| author_facet | K. Lakkala A. Arola A. Heikkilä J. Kaurola T. Koskela E. Kyrö A. Lindfors O. Meinander A. Tanskanen J. Gröbner G. Hülsen |
| author_sort | K. Lakkala |
| collection | DOAJ |
| description | The quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calculation of long-term spectral responsivity, data processing and quality assessment. The cosine correction of the measurements is based on a new method, and is included in the data processing software. The results showed that the actual cosine correction factor of the two Finnish Brewers can vary between 1.08–1.13 and 1.08–1.12, respectively, depending on the sky radiance distribution and wavelength. The temperature characterization showed a linear temperature dependence between the instruments' internal temperature and the photon counts per cycle, and a temperature correction was used for correcting the measurements. The long-term spectral responsivity was calculated using the time series of several lamps using two slightly different methods. The long-term spectral responsivity was scaled to the irradiance scale of the Helsinki University of Technology (HUT) for the whole of the measurement time-periods 1990–2006 and 1995–2006 for Sodankylä and Jokioinen, respectively. Both Brewers have participated in many international spectroradiometer comparisons, and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002–2007. |
| first_indexed | 2024-12-12T11:51:59Z |
| format | Article |
| id | doaj.art-2ffa82aad2e34ee8b7eac94ec3fcca0f |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-12T11:51:59Z |
| publishDate | 2008-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-2ffa82aad2e34ee8b7eac94ec3fcca0f2022-12-22T00:25:18ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242008-06-0181333693383Quality assurance of the Brewer spectral UV measurements in FinlandK. LakkalaA. ArolaA. HeikkiläJ. KaurolaT. KoskelaE. KyröA. LindforsO. MeinanderA. TanskanenJ. GröbnerG. HülsenThe quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calculation of long-term spectral responsivity, data processing and quality assessment. The cosine correction of the measurements is based on a new method, and is included in the data processing software. The results showed that the actual cosine correction factor of the two Finnish Brewers can vary between 1.08–1.13 and 1.08–1.12, respectively, depending on the sky radiance distribution and wavelength. The temperature characterization showed a linear temperature dependence between the instruments' internal temperature and the photon counts per cycle, and a temperature correction was used for correcting the measurements. The long-term spectral responsivity was calculated using the time series of several lamps using two slightly different methods. The long-term spectral responsivity was scaled to the irradiance scale of the Helsinki University of Technology (HUT) for the whole of the measurement time-periods 1990–2006 and 1995–2006 for Sodankylä and Jokioinen, respectively. Both Brewers have participated in many international spectroradiometer comparisons, and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002–2007.http://www.atmos-chem-phys.net/8/3369/2008/acp-8-3369-2008.pdf |
| spellingShingle | K. Lakkala A. Arola A. Heikkilä J. Kaurola T. Koskela E. Kyrö A. Lindfors O. Meinander A. Tanskanen J. Gröbner G. Hülsen Quality assurance of the Brewer spectral UV measurements in Finland Atmospheric Chemistry and Physics |
| title | Quality assurance of the Brewer spectral UV measurements in Finland |
| title_full | Quality assurance of the Brewer spectral UV measurements in Finland |
| title_fullStr | Quality assurance of the Brewer spectral UV measurements in Finland |
| title_full_unstemmed | Quality assurance of the Brewer spectral UV measurements in Finland |
| title_short | Quality assurance of the Brewer spectral UV measurements in Finland |
| title_sort | quality assurance of the brewer spectral uv measurements in finland |
| url | http://www.atmos-chem-phys.net/8/3369/2008/acp-8-3369-2008.pdf |
| work_keys_str_mv | AT klakkala qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT aarola qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT aheikkila qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT jkaurola qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT tkoskela qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT ekyro qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT alindfors qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT omeinander qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT atanskanen qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT jgrobner qualityassuranceofthebrewerspectraluvmeasurementsinfinland AT ghulsen qualityassuranceofthebrewerspectraluvmeasurementsinfinland |