nephelometry

The art of measuring, observing, or studying the general cloudiness of the sky.

The art of measuring the size, growth, and other changes of a particular cloud.

The application of the photogrammeter to cloud-work.

The measurement of the concentration of a solution, suspension or dispersion based upon its light-scattering properties.

Technique used to determine levels of antibodies or antigens in a suspension based up its light-scattering properties.