The solar irradiance is the output of light energy from the entire disk of the Sun, measured at the Earth.
The area on the ground that an imaging system, such as a satellite sensor, can distinguish.
The ratio of the relative amplitude of the response of a detector and the frequency of incident electromagnetic radiation.
An optical instrument that splits the light received from an object into its component wavelengths by means of a diffraction grating, and then measures the amplitudes of the individual wavelengths.
An orbit in which a satellite is always in the same position with respect to the rotating Earth at the same time of day.
Surface reflectance is defined as the fraction of incoming solar radiation that is reflected from Earth's surface for specific incident or viewing cases (directional, conical, and hemispherical cases).