Avionics News April 2015 - 20

ADS-B IN

Continued from page 19

Fortunately, the laws that govern product adoption and
price appear to be in play. ADS-B Out solutions available
today cost about half what they cost in 2012. Avoiding ADS-B
In helps keep down costs - particularly for aircraft lacking a
screen needed to display ADS-B In products.
Today, some combination solutions - ones offering the
WAAS GPS position source, the Out transmitter and the In
receiver - also offer wireless feeds of the ADS-B In data
packages, allowing those users to display the graphics and
texts on a portable device - a tablet, smartphone or notebook
computer, running the appropriate software.
Back to our pilot friend from earlier, "The kicker for me was
learning that a package of ADS-B Out and In will get me all
the traffic all the time - and all the weather-data info," he said.
"I didn't understand that In alone limits the traffic you get, and
to receive all of what In provides I needed Out, too, especially
when the transponder started 'winking out' at the worst times."
Here's a brief rundown of what's available through ADS-B In:
Flight Information System-Broadcast
FIS-B broadcasts its products via the national network of
ground stations shown on the map, courtesy of the FAA.

NOTE: Coverage areas and tower locations are appoximate, with network map

current as of March 2014. Depicts typical airborne reception at approximately 1,500
feet AGL. User's signal reception range may vary depending on receiver altitude
above ground and any intervening physical obstructions to line of sight uplink.

Within FIS-B, the FAA delivers
a number of products
*
Nexrad Weather Radar - Arguably the most popular
in-demand service of the weather products available,
it provides a full-color depiction of precipitation
and thunderstorms right on the moving map. Images
showing detailed regional radar images arrive about
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april

2015

every five minutes showing conditions within 250
nautical miles of the aircraft's current position. Despite
the update frequency, it's important to remember that
a latency period applies - the time it takes to gather,
process and deliver radar pages. So the real age of the
graphic runs somewhere between five and 10 minutes
old when you first see it. As with the satellite services,
the provider considers the data appropriate only for
long-range strategic planning - not in-proximity
navigating of storm cells. Images covering beyond
250 nautical miles of the aircraft, called national radar,
show slightly less detail and is updated one-third as
often - every 15 minutes.
*
Terminal area forecasts - Our old friend TAF, in its old
familiar format.
*
Meteorological terminal aviation routine weather
report - Our other old friend, METAR, also in the
usual format.
*
Winds aloft - No need to land to look at a map or call
flight service; the data is available with FIS-B.
*
Pilot reports - Another old, familiar item pilots love to
use ... when other pilots file them, that is.
*
AirMets and SigMets - Once again, a live update
in the cockpit when a call to FSS might not yield a
contact.
*
TFR - Yes, and they get updated about as fast as
they're made available.
*
Notices to airmen - Our old, familiar NOTAM format
also is delivered via FIS-B.
Some of these specific pages offer options in how they're
displayed. For example, the user can quickly see whether an
airport is reporting IFR conditions; conditions such as icing
also are visible on these weather pages. And FIS-B broadcasts
come only on 978 MHz, while TIS, TIS-B and all other traffic
forms are broadcast on both 1090 ES and 978. Also, the FAA
notes that future services possible on FIS-B also will come on
the 978 data package thanks to its robust residual capacity.
Extending the reach of see-and-avoid: TIS-B
In addition to these weather-related data packages, the
FAA also offers another helpful situational-awareness tool
via ADS-B In: the traffic information service-broadcast, or
TIS-B, broadcast on both 1090 ES and 978 MHz.
Similar in use to radioed VFR radar traffic advisories, TIS-B
exists to improve the safety, efficiency and effectiveness of "see and
avoid" flight through a graphic display that automatically informs the
pilot of nearby traffic and possible conflicts so the pilot can quickly
visually acquire those planes.
TIS-B can provide an estimated position, altitude, altitude trend
and ground track for as many as eight other aircraft within 7 nautical
Continued on page 22
Avionics News April 2015

Table of Contents for the Digital Edition of Avionics News April 2015
