1. Thermography: general information

1.1 Terminology

Etymologically, thermography means "to write heat" or "to write with heat".

In general, thermography refers to any technique for representing ("writing") in space and/or time the thermal state of a scene under consideration. The thermal state is related to heat or temperature.

In our context, this representation is obtained by recording the electromagnetic radiation emitted by the scene. This radiation, which carries information on the thermal state, is commonly referred to as "thermal radiation".

1 – Thus presented, thermography (by radiation) would be a special case of photography ("writing – with – light"). Just as photography provides a "photograph", thermography produces a "thermograph" (we'll...