Garmin 695, 696 owner manual TIS-A Limitations, Terminal Mode S radar site map

Hazard Avoidance Flight Planning GPS Navigation Overview

Appendix E

TIS-A LIMITATIONS

TIS-A relies on surveillance of the Mode-S radar system, which is a “secondary surveillance” radar system similar to that used by ATCRBS. Many limitations are inherent in secondary radar surveillance. Information provided by TIS-A is neither better nor more accurate than the information used by ATC. TIS-A is intended only to assist in visual acquisition of other aircraft in visual meteorological conditions (VMC). While TIS-A is a useful aid for visual traffic avoidance, system limitations must be considered to ensure proper use. No recommended avoidance maneuvers are given, nor authorized, as a direct result of a TIS-A intruder display or TIS-A advisory.

•TIS-A operation may be intermittent during turns or other maneuvering.

•TIS-A is dependent on two-way, line-of-sight communications between the aircraft and the Mode-S radar antenna. Whenever the structure of the aircraft comes between the transponder antenna and the ground-based radar antenna, the signal may be temporarily interrupted.

NOTE: Refer to the TIS-A Limitations section of the Aeronautical Information Manual (AIM) for a more comprehensive explanation of limitations and

anomalies associated with TIS-A.

Features
		NOTE: TIS-A is unavailable at low altitudes in many area of the United States.
Additional		This is often the case in mountainous regions.
		NOTE: Garmin is not responsible for Mode S geographical coverage. Operation
Appendices		of the ground stations is the responsibility of the FAA. Refer to the AIM for a
		Terminal Mode S radar site map.
	TIS-A information is collected during a single radar sweep. Collected information
	is then sent through the Mode S uplink on the next radar sweep. Because of this, the
	surveillance information is approximately five seconds old. TIS-A ground station tracking
Index	software uses prediction algorithms to compensate for this delay. These algorithms
	use track history data to calculate expected intruder positions consistent with the time
	of display. Occasionally, aircraft maneuvering may cause variations in this calculation
	and create slight errors on the Map Page which affect relative bearing information and

218 Garmin GPSMAP 695/696 Owner’s Manual 190-00919-00 Rev. F