radiometriska

Radiometriska, or radiometric in English, describes the measurement and quantification of electromagnetic radiation. It encompasses the science and methods used to assess radiant energy across the spectrum, from infrared to ultraviolet and beyond. Radiometry is concerned with physical quantities that are independent of human vision, in contrast to photometry, which weights measurements by the eye’s response.

The core radiometric quantities include radiant flux or power (measured in watts), irradiance (power per unit area, W/m^2), radiance (power per unit area per unit solid angle, W/m^2/sr), and spectral radiance (W/m^2/sr per wavelength). These quantities can be defined for total or spectral values, and they underpin how instruments translate detected signals into comparable physical units. Radiometric measurements rely on calibrated detectors, such as radiometers and spectroradiometers, and on reference sources and standards to ensure accuracy.

Calibration and instrumentation are essential in radiometriska work. Absolute radiometric calibration ties instrument responses to known radiometric standards, often using blackbody sources or calibrated lamps. Relative calibration and radiometric correction are used to compare data from different sensors or to account for atmospheric and environmental effects. In remote sensing, radiometric calibration is crucial for converting sensor counts to physical radiance or reflectance, enabling cross-sensor comparisons and quantitative analysis of surface properties.

Applications span astronomy, climate science, and geoscience. Radiometriska methods support satellite imaging, solar and atmospheric research, and radiometric dating in geochronology, where isotope decay provides age estimates. The field emphasizes traceability, spectral fidelity, and understanding how measurement processes interact with the radiation being studied.