When you describe a physical process, for example,
the weather on Earth, or an engineered system, such
as a self-driving car, you typically have two sources of
information. The first is a mathematical model, and
the second is information obtained by collecting data.
To make the best predictions for the weather, or most
effectively operate the self-driving car, you want to
use both sources of information. Data assimilation
describes the mathematical, numerical and computational
framework for doing just that.