Pilot's Guide

23190-00587-02 Rev. B
Garmin GTS Traffic Systems
GLOSSARY
Active Surveillance: Tracking of traffic targets using aircraft transponders
ADS-B: Automatic Dependent Surveillance – Broadcast
ATCRBS: Air Traffic Control Radio Beacon Service - A surveillance
system that uses active interrogations and Mode A/C
replies from transponders
CLEAR CAS: Correlated Location Enhanced ADS-B Receiver Collision
Avoidance System
GPS: Global Positioning System
MHz: MegaHertz - A unit of measure for radio frequency
Mode A: A type of ATCRBS transmission which requests (via Mode
A interrogations) or reports (via Mode A replies) aircraft
identity information
Mode C: A type of ATCRBS transmission which requests (via Mode
C interrogations) or reports (via Mode C replies) aircraft
altitude information
Mode S: A type of secondary surveillance radar transmission which
contains a unique 24-bit discrete address, thus allowing
interrogations to be addressed to individual aircraft. Mode
S transmissions can be short (56 bits) or long (112 bits),
with long transmissions containing a 56-bit “message”
field.
NM: Nautical Mile
OT: Other Traffic (other than TA or PA traffic)
PA: Proximity Advisory
Passive Surveillance: Tracking and enhancement of traffic targets using ADS-B
broadcasts
TA: Traffic Advisory
TAS: Traffic Advisory System
TCAS: Traffic Alert and Collision Avoidance System