Garmin GDL 88 Series Pilots Guide - Page 12

2.1 Automatic Dependent Surveillance - Broadcast (ADS-B) ADS-B is the automatic broadcast of position reports by aircraft, surface vehicles, and transmitters on fixed objects. These broadcasts contain much more data than just a simple position report, they include: identity (Flight ID, Call Sign, Tail Number, ICAO registration number, etc), ground track, ground speed, pressure altitude, indications of multitude capabilities, and emergency status. Figure 2-3 ADS-B Operation - FAA Illustration Garmin display units have the capability to show the status of the ground station services being received. Examples for the GTN and GNS products are shown below. See the display device Pilot Guide for the symbology used on that display. Unit Symbol Description GNS Within coverage of a TIS-B ground station. GNS Not within coverage of a TIS-B ground station. GNS GDL 88 does not have a valid track or heading and cannot place ADS targets on the display. GTN Within coverage of a TIS-B ground station. GTN Not within coverage of a TIS-B ground station. Table 2-1 Map TIS-B Availability Symbols for the GDL 88 2-2 Garmin GDL 84/88 ADS-B Transceiver Pilot's Guide 190-01122-03 Rev. E