GTS Traffic Systems Pilot’s Guide
© 2014 Garmin Ltd. or its subsidiaries. All rights reserved. Garmin International, Inc., 1200 East 151st Street, Olathe, KS 66062, U.S.A. Tel: 913/397.8200 Fax: 913/397.8282 Garmin AT, Inc., 2345 Turner Road SE, Salem, OR 97302, U.S.A. Tel: 503/391.3411 Fax 503/364.2138 Garmin (Europe) Ltd., Liberty House, Bulls Copse Road, Hounsdown Business Park, Southampton, SO40 9LR, U.K. Tel. +44 (0) 23 8052 4000 Fax +44 (0) 23 8052 4004 Garmin Corporation, No.
LIMITED WARRANTY This Garmin product is warranted to be free from defects in materials or workmanship for two years from the date of purchase. Within this period, Garmin will, at its sole option, repair or replace any components that fail in normal use. Such repairs or replacement will be made at no charge to the customer for parts and labor, provided that the customer shall be responsible for any transportation cost.
WARNINGS AND CAUTIONS WARNING: The GTS TAS and TCAS I systems are intended for advisory use only to aid the pilot in visually acquiring traffic. No avoidance maneuvers should be based solely upon traffic information. It is the responsibility of the pilot in command to see and maneuver to avoid traffic. CAUTION: Pilots should be aware of TAS/TCAS I system limitations. TAS/TCAS I systems require intruder transponders to respond to system interrogations.
Contents LIMITED WARRANTY.........................................................................................i Warnings and Cautions....................................................................................ii System Description..........................................................................................3 General Theory of Operation.............................................................................. 3 Active Surveillance...................................................
Radar Altimeter........................................................................................ 18 Calculated Height Above Ground.............................................................. 18 ADS-B Receiver............................................................................................... 18 Self-Test.......................................................................................................... 20 Q and A.....................................................................
SYSTEM DESCRIPTION Garmin GTS Traffic Systems are a family of Traffic Advisory Systems (TAS) and Traffic Alert and Collision Avoidance Systems (TCAS). The systems feature both active interrogation of aircraft transponders and passive surveillance of 1090 MHz Extended Squitter ADS-B broadcasts (1090ES).
Passive Surveillance GTS Traffic Systems can optionally utilize passive surveillance information from an internal ADS-B receiver. The ADS-B receiver uses 1090ES broadcasts from other aircraft that are equipped with 1090ES ADS-B Out. These broadcasts are combined with the active surveillance data to enhance the accuracy of target positions on the display. This is Garmin’s CLEAR CASTM technology, which correlates ADS-B and actively interrogated targets to provide pilots with the most accurate target position.
System Components System Processor Each GTS Traffic System includes a system processor. The system processor connects to all of the required and optional antennas, displays, controls, and aircraft interfaces. Figure 1 GTS System Processor GTS 800/820/850 System Processors The GTS 800/820/850 systems use a unique system processor. The GTS 800 system processor is different from a GTS 820 or GTS 850 system processor.
Antennas The GTS Traffic Systems use one or two dedicated externally-mounted antennas to transmit transponder interrogations to other aircraft. The same antenna or antennas are used to receive transponder replies and ADS-B broadcasts from other aircraft. A directional antenna on top of the aircraft is always required and is used to determine the bearing to the intruder aircraft.
Sensor Systems Low-Profile Antenna Sensor Systems antennas are low-profile directional antennas that may be installed on the top and/or bottom of the aircraft. Figure 3 Sensor Systems Low-Profile Directional Antenna Omni-Directional Antenna Numerous omni-directional (monopole) antennas are suitable for installation on the bottom of the aircraft. Omni-directional antennas cannot determine the bearing to an intruder aircraft. Figure 4 Bottom-Mounted Omni-Directional (Monopole) Antenna 190-00587-02 Rev.
External Amplifier GPA 65 Amplifier Module (GTS 820 & 850 only) The GPA 65 is a combined Power Amplifier and Low Noise Amplifier that is required for use with the GTS 820 and GTS 850 systems only. Figure 5 GPA 65 PA/LNA Module 8 Garmin GTS Traffic Systems 190-00587-02 Rev.
System Interfaces The GTS Traffic System includes interfaces to various required and optional aircraft systems. Altitude Source At least one pressure altitude source is required for system operation. The pressure altitude source is compared to the pressure altitude replies from other aircraft to calculate their relative altitudes. Pressure altitude interfaces are available from a serial altitude encoder or digital air data computer.
Landing Gear Position Landing gear position for retractable gear aircraft is interfaced to the GTS system. Landing gear position may be used to mute traffic advisory audio, adjust the sensitivity of traffic alerts, or compensate a bottom directional antenna. Radar Altimeter A radar altimeter may be optionally interfaced to the GTS system. Radar altimeter height may be used to mute traffic advisory audio, adjust the sensitivity of traffic alerts, or filter out traffic targets that are on/near the ground.
SYSTEM OPERATION Operating Modes The system typically powers up in Standby mode. In Standby mode, the system is powered on, but no traffic surveillance functions are performed. Operate mode is the normal mode for operations. All active and passive traffic surveillance functions are performed in Operate mode. Self-test mode is a manually-selected mode that briefly performs a test of the system. Refer to the self-test section of this guide for additional information.
Intruder Altitude and Vertical Trend Figure 6 Example Traffic Display NOTE: Always refer to the traffic display documentation for details on how traffic information is depicted on each display. Other Traffic (OT) Other Traffic (OT) targets are typically displayed as a hollow diamond and do not meet the criteria for any other traffic type. Proximity Advisories (PA) Proximity Advisory (PA) targets are typically displayed as a solid diamond.
choosing the sensitivity level is based on available system inputs. If none of the inputs described below are available, the system will always remain in the most sensitive level, SL B. Radar Altimeter If the aircraft is equipped with a radar altimeter, SL A will be used when the radar altitude is less than 2,000 feet. SL B will be used when the radar altitude is greater than 2,000 feet.
Sensitivity Intruder Altitude Level Available A Yes A No B Yes B No TA Alerting Conditions Intruder closing rate provides less than 20 seconds of vertical and horizontal separation. Or: Intruder closing rate provides less than 20 seconds of horizontal separation and vertical separation is within 600 feet. Or: Intruder range is within 0.2 NM and vertical separation is within 600 feet. Intruder closing rate provides less than 15 seconds of separation or intruder range is within 0.2 NM.
No-Bearing TA Traffic Annunciation Figure 7 No-Bearing TA Off-Scale TAs If a TA is beyond the currently-selected traffic display range, it is typically shown with a half-circle icon at the edge of the display range. Refer to the traffic display documentation for details regarding off-scale TA depictions. TA Aural Alerts When a target becomes a TA, an aural alert message is played to advise the crew. The aural alert may include an ATC-description of the target’s bearing, altitude, and distance.
TA Aural Muting TA aural alerts may be muted or canceled under some circumstances. Muting or canceling of the TA aural alert does not affect the visual display of the TA. Radar Altimeter If the aircraft is equipped with a radar altimeter, all TA aural alerts will be muted when the radar altitude is less than 400 feet. Landing Gear Position If the aircraft has retractable landing gear, all TA aural alerts will be muted when the landing gear is extended.
Automatic Mode Switching The system can automatically switch between Operate and Standby modes based on whether the ownship is in the air or on the ground. The system will automatically select Operate mode 8 seconds after becoming airborne. Standby mode will automatically be selected 24 seconds after landing. Calculated Height Above Ground For aircraft that are not equipped with a radar altimeter, the system can calculate the height above ground using information from various optional interfaces.
Ground Traffic Filtering To reduce nuisance alerts and reduce traffic display clutter, traffic that is on or near the ground may not be shown on the traffic display or generate traffic alerts. There are several methods used for filtering out ground traffic. Mode S Targets Mode S transponders include in their replies an indication of whether the aircraft is on the ground or in the air. Mode S traffic that indicates the traffic is on the ground will not be displayed or generate an alert.
NOTE: The ADS-B receiver is a 1090ES receiver and cannot receive 978 MHz UAT broadcasts. Air-to-air broadcasts from other aircraft equipped with 1090ES ADS-B Out are used for traffic correlation. Traffic or weather uplinks from ADS-B ground stations are not used. ADS-B broadcasts must be correlated with an active transponder reply in order to be shown on the traffic display. Uncorrelated ADS-B broadcasts are not used, and ADS-B correlation is not used for Traffic Advisories.
Self-Test NOTE: Traffic surveillance is not available during the self-test. The self-test mode is used to verify that the system is functioning normally. Self-test must be manually initiated from the Standby mode and takes approximately ten seconds to complete. During the self-test, a pattern of traffic symbols is shown on the traffic display. The test pattern consists of the following traffic: • A Traffic Advisory at 9 o’clock, 2 miles, 200 feet below and climbing.
Q AND A What are the benefits of ADS-B? 1090 MHz Extended Squitter ADS-B data contains additional information about a target aircraft including flight ID, latitude, longitude, barometric and geometric altitude, velocity, and direction. This provides precise location information about the target aircraft. Targets within the active surveillance range that are correlated with ADS-B data are displayed with much greater accuracy as a result of this.
What kind of transponder is required for use with the GTS Traffic System? All installations except the GTS 800 require the use of a compatible Mode S transponder. The transponder provides an indication of how many other TCAS-equipped aircraft are nearby, so that the GTS traffic system can adjust its transmit power and reduce frequency congestion. The GTS 800 does not require a transponder interface (regulatory requirements for transponder usage still apply).
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
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© 2014 GARMIN Corporation GARMIN International, Inc. 1200 East 151st Street, Olathe, Kansas 66062, U.S.A. Tel. 913/397.8200 or 800/800.1020 Fax 913/397.8282 Garmin AT, Inc. 2345 Turner Rd., S.E., Salem, Oregon 97302, U.S.A. Tel. 503/581.8101 or 800/525.6726 Fax. 503/364.2138 Garmin (Europe) Ltd. Liberty House, Bulls Copse Road, Hounsdown Business Park, Southampton, SO40 9LR, U.K. Tel. +44 (0) 23 8052 4000 Fax +44 (0) 23 8052 4004 GARMIN Corporation No.
