Sensitivity time control

From Glossary of Meteorology

sensitivity time control

(Abbreviated STC.) The term, now somewhat obsolete, used to denote the procedure of reducing the sensitivity of a radar receiver at close ranges to compensate for the limited dynamic range of the receiver and avoid saturation.

The primary disadvantage of STC is that weak echoes at close range may be undetected because of the lowered sensitivity. The term is sometimes used erroneously to denote range correction of the received power to compensate for the inverse-square falloff of the power from distributed targets with range.
See radar equation.