Appendix i radiometric terminology – Campbell Scientific Kipp and Zonen CMP-Series Pyranometers User Manual
Page 30

CMP/CMA series manual
Page
29
Appendix I Radiometric terminology
Term
Explanation
Albedo
The portion of incoming radiation which is reflected by a surface
Azimuth angle
Angle in horizontal direction (0-360
°)
Angle of incidence
Incident angle from zenith (vertical)
Cosine response
Detector response according to the cosine law
Diffuse solar irradiance
Solar radiation, scattered by water vapor, dust and other particles as
it
passes
through
the
atmosphere
Direct solar irradiance
Radiation that has travelled a straight path from the sun
Global solar irradiance
Total irradiance falling on a horizontal surface
(Diffuse + Direct
⋅ cos α)
Irradiance Radiant flux density (W/m
2
)
Long-wave radiation
Radiation with wavelengths > 4 µm and < 100 µm
Pyranometer
Radiometer suitable to measure short-wave global radiation
Pyrgeometer
Radiometer suitable to measure downward long-wave radiation
Pyrheliometer
Radiometer suitable to measure direct irradiance
Short-wave radiation
Radiation with wavelengths > 280 nm and < 4 µm
Thermopile
Thermal detector mad up of many thermocouple junctions
WMO
World Meteorological Organisation
WRC
World Radiation Center (in Davos, Switzerland)
WRR
World Radiation Reference (standard radiation scale)
WSG
World Standard Group (radiometer standards maintained in Davos)
Zenith angle
Angle from zenith (0
°, vertical)