A Closer Look at Internet Traffic in ForeFlight

ForeFlight’s May 2020 release introduces Internet Traffic.  Powered by FlightAware’s industry-leading data fusion platform and the world’s largest ADS-B network, the Traffic map layer that is already familiar to users of ADS-B In receivers now doubles as a means of displaying global traffic targets within ForeFlight when connected to the internet.  The best part?  This feature is available to all ForeFlight customers.

Internet Traffic is a great supplement to traffic received directly from an ADS-B receiver, as its intended use is entirely different.  An ADS-B receiver shows aircraft position in real time with high-frequency position reports, but only displays a limited volume of traffic targets in relative close proximity to your aircraft.  For those reasons, it often doesn’t do you much good on the ground or when looking to see how traffic is flowing along your flight path or at your destination airport.  

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Internet Traffic, on the other hand, streams traffic targets from all around the world.  There is some delay in transmission and, with the majority of the traffic targets coming from ADS-B receivers on the ground, there are gaps in coverage that vary by altitude and distance from ground receivers.  As such, Internet Traffic should never be used for navigation or collision avoidance and is intended to be used solely for reference and situational awareness.  As a result, you will not find Internet Traffic targets in Synthetic Vision and will not receive aural alerts for nearby targets.  The Hide Distant Traffic setting also will not impact Internet Traffic.  

Internet Traffic is a great tool for checking which runways are being used at your departure and arrival airports before you set off to plan your taxi, departure, and arrival procedures.  You might check to see if aircraft are making it around or above weather systems to enhance your go/no-go decision-making.  It’s also simply a lot of fun to see what’s going on at your local airport from the comfort of your own home and with all the familiar map features available in ForeFlight.

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Internet Traffic can be enabled via the Traffic layer, which is now always available when connected to the internet.  Compatible ADS-B or FLARM devices and connected flight simulators will utilize the same layer, disabling internet traffic until you disconnect from the device.  Only one source of traffic information is allowed at once, with priority given to traffic from connected receivers and flight simulators.  When you’re flying without an ADS-B receiver, the traffic layer selector will be hidden and Internet Traffic will not be displayed, even if you have a working cellular connection.  However, connecting to inflight Wi-Fi networks from Gogo or Satcom Direct will allow Internet Traffic to be reactivated.  When the Internet Traffic is enabled, a white “Internet Traffic” label in the upper-left corner of the map will be displayed to help you understand your active source of traffic information. 

We’ve optimized Internet Traffic to use roughly 10 megabytes of data per hour, but this will vary based on the position and zoom level of the map and the number of onscreen traffic targets – viewing the middle of the Pacific ocean will require far less bandwidth than Florida on a sunny weekend.  If inflight bandwidth is a concern, ForeFlight Performance customers have the option to prevent ForeFlight from streaming internet data while connected to a Gogo or Satcom Direct inflight router.  Deactivating the Traffic layer in the layer selector will also prevent ForeFlight from streaming traffic data.

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Airborne Internet Traffic targets appear in ForeFlight as cyan chevrons pointed in the direction of motion.  Zooming in far enough will display the target call sign or tail number and altitude.  In contrast to traffic received directly from an ADS-B receiver, a course vector is not displayed for each traffic target, and each target’s pressure altitude is displayed directly, rather than its altitude relative to your own. Tapping a target will display a popover with additional information about the target, including distance in nautical miles and cardinal direction from your position, ground track in degrees, groundspeed in knots, aircraft type, and the age of the last reported position in seconds.  Blocked tails do not display registration or call sign information.

Traffic targets are streamed based on the current map position and zoom level.  Two-axis filtering will effectively show you all available traffic targets within the rectangular area of the map.  If your map is only displaying the state of Texas, you will only stream traffic targets in the state of Texas.  Pan to Oklahoma, and you’ll stream targets there. Intuitive zoom-level filtering prevents clutter by filtering traffic at various altitudes.  When you’re zoomed out to show more than the state of Texas, the map will only show targets above 39,000 feet.  When you’re zoomed in such that you can see most of Texas, you’ll see traffic above 12,000 feet.  With Houston, Austin, and Dallas within view, you’ll see targets as low as 6,000 feet.  Looking at the whole of the Houston metro area and you’ll see all available traffic targets.  Zoom in such that ForeFlight’s embedded airport diagrams appear and you’ll lose traffic above 15,000 feet so that you don’t experience high-altitude traffic zip through at 500 knots while you’re checking out what’s going on near the ground with comparatively slower movement. 

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Aircraft on the ground will show up as tan chevrons at thousands of airports worldwide when zoomed into the airport environment.  Properly equipped ground vehicles may show in similar fashion.  In addition to color, ground traffic can be differentiated from airborne traffic by the SFC and Ground tags in the popover and their lack of an altitude value above the marker.  

Ground positions stream in quickly and frequently – typically every second or two – and thus are not smoothly animated from point to point.  Conversely, airborne positions are often updated less frequently and are smoothly animated between actual reported positions by interpolating their movement.  You’ll note the age of the target’s last reported position in the on-tap popover.  The larger the number, the larger the potential discrepancy between the aircraft’s actual current position and where it is displayed on the map.  This counter never quite resets to 0, as ForeFlight takes the difference between the time of the aircraft’s last known position and the current time.  There is some natural latency in streaming traffic positions from around the globe, which means the positions are typically between five and ten seconds old by the time they reach your device.  In cases where an aircraft has landed or has otherwise departed the coverage area, ForeFlight will age out markers after 120 seconds.

The majority of traffic positions are derived from ADS-B receivers, but positions may be reported by other means.  ASDE-X is installed at 35 of the busiest airports in the United States and provides enhanced coverage in the airport environment.  Some non-ADS-B equipped aircraft will be displayed via multilateration (MLAT) if the aircraft is within proximity of four or more ADS-B ground stations.  FlightAware may also provide estimated positions for aircraft in some larger areas of limited ADS-B coverage, such as for aircraft transiting the North Atlantic.  When FlightAware is receiving overlapping data from multiple sources, FlightAware’s feed interpreter will choose the position from the most reliable available source that also allows positions to be evenly spaced in time.

Looking for enhanced coverage close to home?  Request a free FlightFeeder from FlightAware or build your own PiAware for under $80!

Internet Traffic brings a whole new perspective to your preflight planning with live global traffic that you can access anywhere.  We are enthusiastically using this new map layer every day and we think it’s going to bring a lot of joy and excitement to your experience with ForeFlight like it has ours.