ABSTRACT
This chapter discusses the vocabulary that will be needed in subsequent discussions. The radiometric calculations are a necessary part of the characterization of detectors and the prediction of signal and noise level. The word radiometry not only describes the detection and measurement of radiated electromagnetic energy, but is also used to describe the prediction and calculation of the power transferred by radiation from one object or surface to another. The concepts of radiometry are similar to those of photometry (related to vision and detection by the human eye) and to the transfer of photons, making it convenient to discuss all three together.
