Abstract
Total solar irradiance (TSI) is the solar energy per unit area received by the Earth. For many years, this energy was considered constant. However, it is known there are variations in different time scales. The TSI absolute value needs to be performed in an extraterrestrial environment due the Earth's atmosphere influence these measurements. The TSI is an important variable to quantify the solar influence on Earth's climate. For this purpose, high precision and stability measurements are necessary. These kind of measurements has proven to be a major technological challenge. This paper describes the operation mode and some characteristics of the electrical substitution radiometer (ESR) used to measure TSI in the space.
Keywords:
electrical substitution radiometer; total solar irradiance; absorbing cavity
