Details
| Original language | English |
|---|---|
| Title of host publication | Atmospheric Radiation |
| Subtitle of host publication | 30 June - 1 July 1993, Tromsö, Norway |
| Place of Publication | Bellingham |
| Publisher | SPIE |
| Pages | 140-151 |
| Number of pages | 12 |
| ISBN (print) | 0-8194-1308-9 |
| Publication status | Published - 2 Nov 1993 |
| Externally published | Yes |
| Event | Atmospheric Radiation 1993 - Tromso, Norway Duration: 27 Jun 1993 → 2 Jul 1993 |
Publication series
| Name | Proceedings of SPIE - The International Society for Optical Engineering |
|---|---|
| Publisher | SPIE |
| Volume | 2049 |
| ISSN (Print) | 0277-786X |
Abstract
Ideally measurements of spectral ultraviolet irradiances require a perfect adaption of the entrance optics to the cosine of the incidence angle. Other requirements of the entrance optics are: No ageing, high throughput at all wavelengths, weatherproofness and no fluorescense of their material. In practice, however, available entrance optics differ by more than 10% from the ideal cosine response for incident angles greater then 60°. Without a correction this introduces a great uncertainty in the absolute measurement of irradiances, especially when the sun is low. A measurement of the angular dependence of the entrance optics and a knowledge of the ratio of the direct to the diffuse component of the global irradiance can be used to correct this cosine error. The correction is dependent on wavelength and sun elevation. For our cosine diffuser the corrections vary between 3% and 18%. The accuracy of the corrections is limited by the accuracy of the measurement of the angular dependence of the cosine diffuser, by the knowledge of the ratio of the direct to the diffuse radiation and by the knowledge of the angular dependence of the radiance of the diffuse component. We assume that our method reduces the overall cosine uncertainty from about ±10% to about ±3%.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Computer Science(all)
- Computer Science Applications
- Mathematics(all)
- Applied Mathematics
- Engineering(all)
- Electrical and Electronic Engineering
Cite this
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Atmospheric Radiation: 30 June - 1 July 1993, Tromsö, Norway. Bellingham: SPIE, 1993. p. 140-151 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 2049).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Cosine error correction of spectral UV-irradiances
AU - Seckmeyer, Gunther
AU - Bernhard, Germar
N1 - Publisher Copyright: © 1993 SPIE. All rights reserved. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.
PY - 1993/11/2
Y1 - 1993/11/2
N2 - Ideally measurements of spectral ultraviolet irradiances require a perfect adaption of the entrance optics to the cosine of the incidence angle. Other requirements of the entrance optics are: No ageing, high throughput at all wavelengths, weatherproofness and no fluorescense of their material. In practice, however, available entrance optics differ by more than 10% from the ideal cosine response for incident angles greater then 60°. Without a correction this introduces a great uncertainty in the absolute measurement of irradiances, especially when the sun is low. A measurement of the angular dependence of the entrance optics and a knowledge of the ratio of the direct to the diffuse component of the global irradiance can be used to correct this cosine error. The correction is dependent on wavelength and sun elevation. For our cosine diffuser the corrections vary between 3% and 18%. The accuracy of the corrections is limited by the accuracy of the measurement of the angular dependence of the cosine diffuser, by the knowledge of the ratio of the direct to the diffuse radiation and by the knowledge of the angular dependence of the radiance of the diffuse component. We assume that our method reduces the overall cosine uncertainty from about ±10% to about ±3%.
AB - Ideally measurements of spectral ultraviolet irradiances require a perfect adaption of the entrance optics to the cosine of the incidence angle. Other requirements of the entrance optics are: No ageing, high throughput at all wavelengths, weatherproofness and no fluorescense of their material. In practice, however, available entrance optics differ by more than 10% from the ideal cosine response for incident angles greater then 60°. Without a correction this introduces a great uncertainty in the absolute measurement of irradiances, especially when the sun is low. A measurement of the angular dependence of the entrance optics and a knowledge of the ratio of the direct to the diffuse component of the global irradiance can be used to correct this cosine error. The correction is dependent on wavelength and sun elevation. For our cosine diffuser the corrections vary between 3% and 18%. The accuracy of the corrections is limited by the accuracy of the measurement of the angular dependence of the cosine diffuser, by the knowledge of the ratio of the direct to the diffuse radiation and by the knowledge of the angular dependence of the radiance of the diffuse component. We assume that our method reduces the overall cosine uncertainty from about ±10% to about ±3%.
UR - http://www.scopus.com/inward/record.url?scp=84968187736&partnerID=8YFLogxK
U2 - 10.1117/12.163506
DO - 10.1117/12.163506
M3 - Conference contribution
AN - SCOPUS:84968187736
SN - 0-8194-1308-9
T3 - Proceedings of SPIE - The International Society for Optical Engineering
SP - 140
EP - 151
BT - Atmospheric Radiation
PB - SPIE
CY - Bellingham
T2 - Atmospheric Radiation 1993
Y2 - 27 June 1993 through 2 July 1993
ER -