Development of a detector-based absolute spectral irradiance scale in the 380–900-nm spectral range

Kärhä, Petri; Toivanen, P.; Manoochehri, Farshid; Ikonen, Erkki

doi:10.1364/ao.36.008909

Cited by 43 publications

(37 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…0.001 mm for a monochromator-based instrument or 0.01 mm for one based on coloured glasses [40]. -The calibrated FRs are then used to measure directly the spectral irradiance or radiance of conventional polychromatic sources such as lamps [41][42][43]. Often, the Planckian radiation of an intermediate, ultra-hightemperature (3500 K) blackbody (UHTBB) is used to interpolate finer spectral intervals for irradiance and radiance measurements, its radiant temperature having been previously determined using a group of FRs across the spectral region of interest.…”

Section: Radiometric Calibration Of An Optical Sensor (A) Traceabilitmentioning

confidence: 99%

Accurate radiometry from space: an essential tool for climate studies

Fox

Kaiser-Weiss

Schmutz

et al. 2011

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

The Earth's climate is undoubtedly changing; however, the time scale, consequences and causal attribution remain the subject of significant debate and uncertainty. Detection of subtle indicators from a background of natural variability requires measurements over a time base of decades. This places severe demands on the instrumentation used, requiring measurements of sufficient accuracy and sensitivity that can allow reliable judgements to be made decades apart. The International System of Units (SI) and the network of National Metrology Institutes were developed to address such requirements. However, ensuring and maintaining SI traceability of sufficient accuracy in instruments orbiting the Earth presents a significant new challenge to the metrology community. This paper highlights some key measurands and applications driving the uncertainty demand of the climate community in the solar reflective domain, e.g. solar irradiances and reflectances/radiances of the Earth. It discusses how meeting these uncertainties facilitate significant improvement in the forecasting abilities of climate models. After discussing the current state of the art, it describes a new satellite mission, called TRUTHS, which enables, for the first time, high-accuracy SI traceability to be established in orbit. The direct use of a 'primary standard' and replication of the terrestrial traceability chain extends the SI into space, in effect realizing a 'metrology laboratory in space'.

show abstract

Section: Radiometric Calibration Of An Optical Sensor (A) Traceabilitmentioning

confidence: 99%

Accurate radiometry from space: an essential tool for climate studies

Fox

Kaiser-Weiss

Schmutz

et al. 2011

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…The realization of the spectral irradiance scale at MIKES is described in Refs. [1][2][3] with detailed uncertainty budgets. The scale is based on absolutely characterized filter radiometers that consist of a trap detector made of three silicon photodiodes, interchangeable filters, and a precision aperture.…”

Section: Measurements At Mikesmentioning

confidence: 99%

Report of the spectral irradiance comparison EURAMET.PR-K1.a.1 between MIKES (Finland) and NIMT (Thailand)

Ojanen¹,

Shpak²,

Kärhä³

et al. 2008

Metrologia

View full text Add to dashboard Cite

A bilateral comparison of the spectral irradiance scales between MIKES (Finland) and NIMT (Thailand) was carried out at 22 wavelengths between 290 nm and 900 nm. MIKES acted as the pilot and link to the results of the key comparison CCPR-K1.a. The spectral irradiance values measured by NIMT generally agree with the key comparison reference value within the expanded uncertainty. Only exceptions are results at wavelengths 300 nm, 450 nm, and 500 nm, where the ratios between the degree of equivalence (DoE) and the expanded uncertainty of DoE (k = 2) are 1.0, 1.4, and 1.2, respectively.

show abstract

“…To extrapolate the values of ρ(λ), Fresnel equations are always used. While it only considers of specular reflectance and is was found in some researches that the corresponding values predicted by the model can not agree with the experimental values well in the UV range of wavelength [2,3,4].…”

Section: Introductionmentioning

confidence: 89%

Specular and diffuse reflectance of silicon photodiodes

Zhou

2007

SPIE Proceedings

View full text Add to dashboard Cite

Now spectral reflectance of silicon photodiodes is described as the reflectance based on thin-film Fresnel formulas and the known refractive indices of the materials of photodiodes. In this paper the diffuse reflectance of light in Si materials is considered. A precision spectrometer is developed to measure the specular and diffuse reflectance of a silicon photodiode over the wavelength range from 400 to 900 nm. The results are compared with the corresponding values predicted by Fresnel model and diffuse model. It is found that the predicted values by Fresnel model show agreement with experimental values of specular reflectance. The diffuse model can predict both specular reflectance and diffuse reflectance well. This result can be used in auto-calibration technology for photodiode spectral response metrology .

show abstract

Development of a detector-based absolute spectral irradiance scale in the 380–900-nm spectral range

Cited by 43 publications

References 21 publications

Accurate radiometry from space: an essential tool for climate studies

Accurate radiometry from space: an essential tool for climate studies

Report of the spectral irradiance comparison EURAMET.PR-K1.a.1 between MIKES (Finland) and NIMT (Thailand)

Specular and diffuse reflectance of silicon photodiodes

Contact Info

Product

Resources

About