Seismic

Detects ground movement for personnel or vehicles.

Magnetic

Detects metal objects such as weapons, vehicles, etc.

Infra-Red

Detects heat signatures of personnel and vehicles.

Break-Beam

Detects intruders when they interrupt a light.

Break-Wire

Detects intruders when they step on a hidden wire.

Acoustic

Detect intruders by listening for vehicles of any sort.

Directional

Detect the direction intruders are traveling.