Comparison of atmospheric spectral radiance measurements from five independently calibrated systems

A variety of instruments have been developed over the past 50 years to measure spectral radiance in absolute units at UV and visible wavelengths with high spectral resolution. While there is considerable experience in the measurement of spectral irradiance, less emphasis has been given to the reliable measurement of spectral radiance from ground observations. We discuss the methodology and calibration procedures for five instruments capable of making such measurements. Four of these instruments are based on double monochromators that scan each wavelength in turn, and one is based on a single monochromator with a charged coupled device (CCD) allowing the recording of all wavelengths simultaneously. The measured spectral radiance deviates between 3% and about 35% depending on the instruments. The results are compared with radiative transfer calculations when the aerosol characteristics of the atmosphere are known.

[1]  Bernhard Mayer,et al.  UV‐B in Germany higher in 1993 than in 1992 , 1994 .

[2]  James B. Kerr,et al.  SUSPEN intercomparison of ultraviolet spectroradiometers , 2001 .

[3]  Martin Huber,et al.  Comparing ground‐level spectrally resolved solar UV measurements using various instruments: A technique resolving effects of wavelength shift and slit width , 1995 .

[4]  R. Schmitt,et al.  Intercomparison of solar UV direct irradiance spectral measurements at Izana in June 2005 , 2005, SPIE Optics + Photonics.

[5]  P. Bener.  Der Einfluß der Bewölkung auf die Himmelsstrahlung , 1963 .

[6]  S. R. Olsen,et al.  An in situ rapid heat–quench cell for small-angle neutron scattering , 2008 .

[7]  Howard W. Yoon,et al.  FASCAL 2: a new NIST facility for the calibration of the spectral irradiance of sources , 2003 .

[8]  M. Blumthaler,et al.  Correction of direct irradiance measurements of Brewer spectrophotometers due to the effect of internal polarization , 2006 .

[9]  Arve Kylling,et al.  Measuring Spectral Actinic Flux and Irradiance: Experimental Results from the Actinic Flux Determination from Measurements of Irradiance (ADMIRA) Project , 2002 .

[10]  D. Wardle,et al.  Investigation of the wavelength accuracy of brewer spectrophotometers. , 1998, Applied optics.

[11]  Howard W. Yoon,et al.  The Fourth SeaWiFS Intercalibration Round-Robin Experiment, SIRREX-4, ed. by S.B. Hooker and E.R. Firestone , 1996 .

[12]  F. E. Nicodemus,et al.  Geometrical considerations and nomenclature for reflectance , 1977 .

[13]  J. Butler,et al.  Uncertainties in radiance calibrations of backscatter ultraviolet (BUV) instruments , 1995 .

[14]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[15]  J. Burrows,et al.  Measurements of nitrogen dioxide total column amounts using a Brewer double spectrophotometer in direct Sun mode , 2006 .

[16]  Gunther Seckmeyer,et al.  Uncertainty of measurements of spectral solar UV irradiance , 1999 .

[17]  Gunther Seckmeyer,et al.  New Spectroradiometers Complying with the NDSC Standards , 2006 .

[18]  Martin Huber,et al.  Effect of inhomogeneous surface albedo on diffuse UV sky radiance at a high‐altitude site , 2004 .

[19]  M. Blumthaler,et al.  Measuring spectral and spatial variations of UVA and UVB sky radiance , 1996 .

[20]  Jay R. Herman,et al.  The effect of polarization sensitivity of Brewer spectrometers on Direct Sun measurements , 2004, SPIE Optics + Photonics.

[21]  S. Sandmeier,et al.  Sensitivity analysis and quality assessment of laboratory BRDF data , 1998 .

[22]  The Effect of Surface Albedo Heterogeneity on Sky Radiance , 2000 .

[23]  Wayne F. J. Evans,et al.  The Automated Brewer Spectrophotometer , 1985 .

[24]  R. Cordero,et al.  Uncertainty evaluation of spectral UV irradiance measurements , 2008 .

[25]  Gunther Seckmeyer,et al.  Spectral radiance and sky luminance in Antarctica: a case study , 2006 .

[26]  C. Dorno.  Studie über Licht und Luft des Hochgebirges , 2022 .

[27]  James J. Butler,et al.  Long-term comparison of spectralon BRDF measurements in the ultraviolet , 2004, SPIE Optics + Photonics.

[28]  Raul R. Cordero,et al.  Uncertainty of experimental integrals: application to the UV index calculation , 2008 .

[29]  A. Bais,et al.  Charge-coupled device spectrograph for direct solar irradiance and sky radiance measurements. , 2008, Applied optics.

[30]  Sigrid Wuttke.  Radiation conditions in an Antarctic environment , 2005 .

[31]  Bernhard Mayer,et al.  Atmospheric Chemistry and Physics Technical Note: the Libradtran Software Package for Radiative Transfer Calculations – Description and Examples of Use , 2022 .