A notification of higher importance than an advisory.
An alarm.
A state of readiness for potential combat.
To give warning to.
Attentive; awake; on guard.
A superior ability to detect something.
A method of detecting distant objects and determining their position, velocity, or other characteristics by analysis of sent radio waves (usually microwaves) reflected from their surfaces
A type of system using such a method, differentiated by platform, configuration, frequency, power, and other technical attributes.
An installation of such a system or of the transmitting and receiving apparatus.
To scan with radar, or as if with radar.