A false traffic icon near your GPS position is typically your own aircraft being detected via ADS-B In but not suppressed from view because ownship detection is not occurring.
Background on ADS-B Traffic
For background, ADS-B receivers detect traffic from individual aircraft broadcasting via ADS-B Out (air-to-air) or from a ground station’s Traffic Information Services - Broadcast (TIS-B).
ADS-B receivers detect traffic directly from aircraft broadcasting ADS-B Out (air-to-air) or from ground stations broadcasting Traffic Information Services - Broadcast (TIS-B).
If your aircraft is ADS-B Out equipped or your Mode C traffic information is broadcast via a ground station, your ADS-B In receiver may detect your aircraft as a traffic target. Normally, ForeFlight compares your GPS position to the detected traffic and hides your aircraft icon when proximity is close enough. When ownship detection fails, a false traffic icon remains visible.
For ADS-B Out Equipped Aircraft
Aircraft that are ADS-B-Out equipped may experience ownship detection failure because:
- The aircraft is not broadcasting ADS-B-compliant data.
- ForeFlight is receiving poor GPS accuracy.
- A ground radar target cannot be reconciled with an ADS-B target due to rapid maneuvers, aerobatics, or radar error.
- The ground station fusion server is malfunctioning.
To determine the source of the error, tap the ghost traffic icon to determine if the traffic target is being received directly (ADS-B) or from a ground station (TIS-B). If the traffic target is TIS-B traffic, get an ADS-B Performance Report for your aircraft to determine if the ADS-B Out setup is performing properly:
Public ADS-B Performance Report Request
If the report shows errors, contact an avionics professional to correct those errors.
If your compliance report shows that your system has no errors, then you can report the problem to the FAA for further investigation by using this form:
ADS-B / TIS-B / FIS-B Problem Report
If the source data for the target shows ADS-B, contact team@foreflight.com.
For Non-ADS-B Out Equipped Aircraft
For non-ADS-B Out equipped aircraft, ownship detection fails when the difference between the GPS position and the aircraft’s broadcast traffic position (from the ground station) exceeds ForeFlight’s proximity detection limits. Unfortunately, this issue cannot be corrected.
Related Article: What does “ownship” mean in ForeFlight Mobile?
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