A. ?-ngströ-m and A. , Radiation to actinometric receivers in its dependence on aperture conditions, Tellus, vol.13, pp.425-431, 1961.

A. ?-ngströ-m, A. Rohde, and B. , Pyrheliometric measurements with special regard to the circumsolar sky radiation, Tellus, vol.18, pp.25-33, 1966.

F. Batlles, F. Olmo, and L. Alados-arboledas, On shadowband correction methods for diffuse irradiance measurements, Solar Energy, vol.54, issue.2, pp.105-1140038, 1996.
DOI : 10.1016/0038-092X(94)00115-T

B. Belhomme, R. Pitz-paal, P. Schwarzbö-zl, and S. Ulmer, A New Fast Ray Tracing Tool for High-Precision Simulation of Heliostat Fields, Journal of Solar Energy Engineering, vol.131, issue.3, p.31002, 2009.
DOI : 10.1115/1.3139139

P. Bendt and A. Rabl, Optical analysis of point focus parabolic radiation concentrators, Applied Optics, vol.20, issue.4, pp.674-683, 1981.
DOI : 10.1364/AO.20.000674

P. Bendt, A. Rabl, H. W. Gaul, and K. A. Reed, Optical Analysis and Optimization of Line Focus Solar Collectors. SERI/TR-34-092, 1979.

N. Benz and T. Kuckelkorn, A new receiver for parabolic trough collectors fields, 12th SolarPACES Int. Symposium, Oxaca (Mexico), 2004.

A. Berk, L. Bernstein, G. Anderson, P. Acharya, D. Robertson et al., MODTRAN Cloud and Multiple Scattering Upgrades with Application to AVIRIS, Remote Sensing of Environment, vol.65, issue.3, pp.367-375, 1998.
DOI : 10.1016/S0034-4257(98)00045-5

F. Biggs and C. N. Vittitoe, Helios: A Computational Model for Solar Concentrators. OSTI ID: 5385022 Report Number(s): SAND-77- 1185C; CONF-770850-1, pp.76-80, 1977.

S. Labs, Resource Relation: Conference: ERDA Solar Workshop on Methods for Optical Analysis of Central Receiver Systems

R. Buck, Solar Power Raytracing Tool SPRAY User Manual, 2010.

D. Buie and A. G. Monger, The effect of circumsolar radiation on a solar concentrating system, Solar Energy, vol.76, issue.1-3, pp.181-185, 2004.
DOI : 10.1016/j.solener.2003.07.032

D. Buie, C. J. Dey, and S. Bosi, The effective size of the solar cone for solar concentrating systems, Solar Energy, vol.74, issue.5, pp.417-427, 2003.
DOI : 10.1016/S0038-092X(03)00156-7

D. Buie, A. G. Monger, and C. Dey, Sunshape distributions for terrestrial solar simulations, Solar Energy, vol.74, issue.2, pp.113-122, 2003.
DOI : 10.1016/S0038-092X(03)00125-7

J. Dersch, P. Schwarzbö-zl, and T. Richert, Annual Yield Analysis of Solar Tower Power Plants With GREENIUS, Journal of Solar Energy Engineering, vol.133, issue.3, p.31017, 2011.
DOI : 10.1115/1.4004355

B. V. Eko-instruments-europe, MS-56 DNI Sensor, 2011.

W. Finsterle, A. Fehlmann, and W. Schmutz, The 11th international pyrheliometer comparison and a saharan dust event, Proc. WMO Technical Conference on Meteorological and Environmental Instruments and Methods of Observation, TECO-2012, pp.16-18, 2012.

N. Geuder and V. Quaschning, Soiling of irradiation sensors and methods for soiling correction, Solar Energy, vol.80, issue.11, pp.1402-1409, 2006.
DOI : 10.1016/j.solener.2006.06.001

N. Geuder, F. Trieb, C. Schillings, R. Meyer, and V. Quaschning, Comparison of different methods for measuring solar irradiation data, 3rd International Conference on Experiences with Automatic Weather Stations, 2003.

N. Geuder, B. Pulvermueller, and O. Vorbrugg, Corrections for rotating shadowband pyranometers for solar resource assessment, Optical Modeling and Measurements for Solar Energy Systems II, 2008.
DOI : 10.1117/12.797472

N. Geuder, M. Hanussek, J. Haller, R. Affolter, and S. Wilbert, Comparison of corrections and calibration procedures for rotating shadowband irradiance sensors, 17th Solar Paces International Symposium, 2011.

P. Gilman, N. Blair, M. Mehos, C. Christensen, S. Janzou et al., Solar Advisor Model User Guide for Version 2.0, pp.670-43704, 2008.
DOI : 10.2172/937349

M. Gnos, On the Development of a Low Cost Pyrheliometer. Graduate School Thesis, pp.2010-90418, 2010.

D. Grether, A. Hunt, and M. Wahlig, Circumsolar Radiation: Correlations with Solar Radiation, 1977.

C. A. Gueymard, SMARTS, a Simple Model of the Atmospheric Radiative Transfer of Sunshine: Algorithms and Performance Assessment, 1995.

C. A. Gueymard, Turbidity Determination from Broadband Irradiance Measurements: A Detailed Multicoefficient Approach, Journal of Applied Meteorology, vol.37, issue.4, pp.414-435, 1998.
DOI : 10.1175/1520-0450(1998)037<0414:TDFBIM>2.0.CO;2

C. A. Gueymard, Parameterized transmittance model for direct beam and circumsolar spectral irradiance, Solar Energy, vol.71, issue.5, pp.325-346, 2001.
DOI : 10.1016/S0038-092X(01)00054-8

C. A. Gueymard, SMARTS Code (Version 2.9.5) User's Manual, 50 pp. <http://rredc.nrel.gov/solar, 2005.

C. A. Gueymard, Spectral Circumsolar Radiation Contribution To CPV, AIP Conf. Proc, vol.1277, p.31, 2010.
DOI : 10.1063/1.3509220

C. A. Gueymard, Solar resource assessment for CSP and CPV, Pt. 2. In: Fifth session of the 2nd Concentrated Solar Power Training, 2010.

C. A. Gueymard and D. R. Myers, Solar Radiation Measurement: Progress in Radiometry for Improved Modeling, Modeling Solar Radiation at the Earth Surface, 2008.
DOI : 10.1007/978-3-540-77455-6_1

M. Hess, P. Kö-pke, and I. Schult, Optical Properties of Aerosols and Clouds: The Software Package OPAC, Bulletin of the American Meteorological Society, vol.79, issue.5, pp.831-844, 1998.
DOI : 10.1175/1520-0477(1998)079<0831:OPOAAC>2.0.CO;2

. Hukseflux, Product Specifications ? DR02 Fast Response First Class Pyrheliometer with Heated Window, 2011.

D. L. King, W. E. Boyson, B. R. Hansen, and W. I. Bower, Improved low-cost solar irradiance sensors, 2nd World Conference and Exhibition on Photovoltaic Solar Energy Conversion, pp.6-10, 1998.
DOI : 10.2172/661542

B. L. Kistler, A User's Manual for DELSOL3: A Computer Code for Calculating the Optical Performance and Optimal System Design for Solar Thermal Central Receiver Plants, pp.86-8018, 1986.

M. Kocifaj and C. A. Gueymard, Theoretical evaluation of errors in aerosol optical depth retrievals from ground-based direct-sun measurements due to circumsolar and related effects, Atmospheric Environment, vol.45, issue.4, pp.1050-1058, 2011.
DOI : 10.1016/j.atmosenv.2010.07.054

P. L. Leary and J. D. Hankins, User's Guide for MIRVAL: A Computer Code for Comparing Designs of Heliostat-receiver Optics for Central Receiver Solar Power Plants, 1979.
DOI : 10.2172/6371450

G. Lemperle, Effect of Sunshape on Flux Distribution and Intercept Factor of the Solar Tower Power Plant at Almería. SSPS No. 3/82, Deutsche Forschungs-und Versuchsanstalt fü r Luft-und Raumfahrt e.V., Kö ln, 1982.

F. Linke, Die Bedeutung des O ¨ ffnungsverhaltnisses eines Aktinometers fü r Messugen des Sonnen und Himmelstrahlung, 1931.

F. Linke and E. Ulmitz, Messungen der zirkumsolaren Himmelstrahlung, Met. Zeit, vol.57, pp.372-375, 1940.

G. Ló-pez, T. Muneer, and R. Claywell, Assessment of four shadow band correction models using beam normal irradiance data from the United Kingdom and Israel. Energy Convers, Manage, vol.45, 1963.

G. Major, An effect of the circumsolar sky radiation on the A ? ngströ m Pyrheliometric scale, Tellus, vol.25, pp.396-399, 1973.

G. Major, A method for determining the circumsolar sky function, Tellus, vol.32, pp.340-347, 1980.

G. Major, Estimation of the error caused by the circumsolar radiation when measuring global radiation as a sum of direct and diffuse radiation, Solar Energy, vol.48, issue.4, pp.249-252, 1992.
DOI : 10.1016/0038-092X(92)90098-U

G. Major, Circumsolar Correction for Pyrheliometers and Diffusometers, 1994.

B. Mayer, Radiative transfer in the cloudy atmosphere. Eur. Phys, J. Conf, vol.1, pp.75-99, 2009.

B. Mayer and A. Kylling, Technical note: The libRadtran software package for radiative transfer calculations &ndash; description and examples of use, Atmospheric Chemistry and Physics Discussions, vol.5, issue.2, pp.1319-1381, 2005.
DOI : 10.5194/acpd-5-1319-2005

S. Meyen and E. Lü-pfert, Measurement of Reflectivity of Optical Components for Concentrating Solar Power Technology, 2009.

J. J. Michalsky, J. L. Berndt, and G. J. Schuster, A microprocessor-based rotating shadowband radiometer, Solar Energy, vol.36, issue.5, pp.465-470, 1986.
DOI : 10.1016/0038-092X(86)90095-2

M. Solar, DN5 and DN5-E First Class Pyrheliometer User's Guide, 2008.

M. I. Mishchenko, Directional radiometry and radiative transfer: A new paradigm, Journal of Quantitative Spectroscopy and Radiative Transfer, vol.112, issue.13, pp.2079-2094, 2011.
DOI : 10.1016/j.jqsrt.2011.04.006

M. I. Mishchenko, Directional radiometry and radiative transfer: The convoluted path from centuries-old phenomenology to physical optics, Journal of Quantitative Spectroscopy and Radiative Transfer, vol.146, pp.4-33, 2014.
DOI : 10.1016/j.jqsrt.2014.02.033

A. Neumann and B. Von-der-au, Sunshape measurements at the DLR solar furnace site in Cologne, Germany. Int. Solar Energy Conf.. American Society of Mechanical Engineers, pp.163-170, 1997.

A. Neumann and A. Witzke, The influence of sunshape on the DLR Solar Furnace beam, Solar Energy, vol.66, issue.6, pp.447-457, 1999.
DOI : 10.1016/S0038-092X(99)00048-1

A. Neumann, A. Witzke, S. A. Jones, and G. Schmitt, Representative Terrestrial Solar Brightness Profiles, Journal of Solar Energy Engineering, vol.124, issue.2, pp.198-204, 2002.
DOI : 10.1115/1.1464880

J. E. Noring, D. F. Grether, and A. J. Hunt, Circumsolar Radiation Data: The Lawrence Berkeley Laboratory Reduced Data Base, 1991.
DOI : 10.2172/6125786

B. Pape, J. Batlles, N. Geuder, R. Zurita-piñ-ero, F. Adan et al., Soiling impact and correction formulas in solar measurements for CSP projects, 15th Solar Paces International Symposium, 2009.

R. Pastiels, Contribution a ` l'e ´tude du problème des méthodes actinométriques, 1959.

A. K. Pierce and C. D. Slaughter, Solar limb darkening, Solar Physics, vol.51, issue.1, pp.25-41, 1977.
DOI : 10.1007/BF00240442

V. Quaschning, W. Ortmanns, R. Kistner, and M. Geyer, Greenius: a new simulation environment for technical and economical analysis of renewable independent power projects. In: Solar Forum 2001 ? Solar Energy: The Power to Choose, 2001.

A. Rabl, Comparison of solar concentrators, Solar Energy, vol.18, issue.2, pp.93-111, 1976.
DOI : 10.1016/0038-092X(76)90043-8

A. Rabl, Active Solar Collectors and their Applications, 1985.

A. Rabl and P. Bendt, Effect of Circumsolar Radiation on Performance of Focusing Collectors, Journal of Solar Energy Engineering, vol.104, issue.3, pp.237-250, 1982.
DOI : 10.1115/1.3266308

B. Reinhardt, On the Retrieval of Circumsolar Radiation from Satellite Observations and Weather Model Output. Dissertation, LMU Mü nchen, pp.19-164380, 2013.

B. Reinhardt, R. Buras, L. Bugliaro, S. Wilbert, and B. Mayer, Determination of circumsolar radiation from Meteosat Second Generation, Atmospheric Measurement Techniques, vol.7, issue.3, pp.823-838, 2014.
DOI : 10.5194/amt-7-823-2014-supplement

I. Rü-edi, Results and Symposium, International Pyrheliometer Comparison, IPC-IX, 2000.

I. Rüedi and W. Finsterle, The World Radiometric Reference and its quality system Instruments and Observing Methods, Proc. WMO Tech. Conf. on Meteorological and Environmental Instruments and Methods of Observation (TECO-2005), pp.434-4363, 2005.

M. Schubnell, Influence of circumsolar radiation on aperture, operating temperature and efficiency of a solar cavity receiver, Solar Energy Materials and Solar Cells, vol.27, issue.3, pp.233-242, 1992.
DOI : 10.1016/0927-0248(92)90085-4

P. Schwarzbö-zl, The User's Guide to HFLCAL. A Software Program for Heliostat Field Layout Calculation, 2009.

F. Vignola, Removing systematic errors from rotating shadowband pyranometer data, Proc. of the 35th ASES Annual Conference, p.pp, 2006.

F. Vignola, J. Michalsky, and T. Stoffel, Solar and Infrared Radiation Measurements (Energy and the Environment), 2012.

C. Vittitoe and F. Biggs, User's Guide to HELIOS: A Computer Program for Modeling the Optical Behavior of Reflecting Solar Concentrators (Part 1). Sandia National Labs, pp.91-1180, 1981.

T. Wendelin, SolTRACE: A New Optical Modeling Tool for Concentrating Solar Optics, Solar Energy, pp.2003-44090, 2003.
DOI : 10.1115/ISEC2003-44090

S. Wilbert, Determination of Circumsolar Radiation and its Effect on Concentrating Solar Power, 2014.

S. Wilbert, R. Pitz-paal, and S. Mü-ller, Rotating shadowband irradiometers and circumsolar radiation, In: COST WIRE Workshop, 2012.

S. Wilbert, B. Reinhardt, J. Devore, M. Roeger, R. Pitz-paal et al., Measurement of Solar Radiance Profiles With the Sun and Aureole Measurement System, Journal of Solar Energy Engineering, vol.135, issue.4, pp.1-11, 2013.
DOI : 10.1115/1.4024244

S. Wilbert, R. Pitz-paal, and J. Jaus, Comparison of measurement techniques for the determination of circumsolar irradiance, Proc. of the International Conference on Concentrator Photovoltaic Systems (CPV-9), 2013.
DOI : 10.1063/1.4822222

S. Wilbert, N. Geuder, E. Lü-pfert, K. Pottler, and R. Pitz-paal, Sunshape measurements with rotating shadowband irradiometers (RSI) In: DLR CSPS, 2013.

R. C. Willson, Experimental and Theoretical Comparison of the International Pyrheliometric Scale, 1969.

F. Wolfertstetter, K. Pottler, A. A. Merrouni, A. Mezrhab, and R. Pitz-paal, A novel method for automatic real-time monitoring of mirror soiling rates, 18th Solar Paces International Symposium, 2012.

F. Wolfertstetter, K. Pottler, N. Geuder, R. Affolter, A. A. Merrouni et al., Monitoring of Mirror and Sensor Soiling with TraCS for Improved Quality of Ground based Irradiance Measurements, 19th Solar Paces International Symposium, 2013.
DOI : 10.1016/j.egypro.2014.03.257

J. G. Wood, Solar Radiation Sensor, 1999.

W. Zdunkowski, T. Trautmann, and A. Bott, Radiation in the Atmosphere: A Course in Theoretical Meteorology, 2007.
DOI : 10.1017/CBO9780511535796