Langley extrapolation

Since aerosols tend to be more concentrated at low altitude, Langley extrapolation is often performed at high mountain sites.

Langley extrapolation is a method for measuring the Sun's radiance with ground-based instrumentation, thereby removing the effect of the atmosphere.

The atmospheric effect can be removed with Langley extrapolation; this method therefore allows measuring the solar extraterrestrial radiance with ground-based measurements.