Kipp&Zonen CGR 4 Pyrgeometers - Manual (Page 30)

Appendix I Radiometric terminology
Term Explanation
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
Global solar irradiance Total irradiance falling on a horizontal surface (Diffuse+Direct • cos α)
Irradiance Radiant flux density (W/m²)
Long-wave radiation Radiation with wavelengths > 4 µm and < 100 µm
Long-wave downward radiation Radiation emitted by the sky
Net radiation Long-wave downward radiation minus outgoing radiation
Pyrgeometer Radiometer suitable to measure downward long-wave radiation
Short-wave radiation Radiation with wavelengths > 280 nm and < 4 µm
Thermopile Thermal detector made up of many thermocouple junctions
WMO World Meteorological Organisation
WRC World Radiation Center (in Davos, Switzerland)
Zenith angle Angle from zenith (0°, vertical)
Page 30 CGR 4 Manual