Radiometry is the scientific study and measurement of electromagnetic radiation, particularly in the form of visible light, ultraviolet light, and infrared radiation. It involves the quantitative measurement of various properties of light, such as its intensity, energy, and spectral characteristics. Radiometry is used in a wide range of applications, including remote sensing, astronomy, photography, and medical imaging. Researchers in this field develop instruments and techniques for accurately measuring and analyzing light, as well as understanding its interactions with matter.