<s>
Automatic	B-Application
Dependent	I-Application
Surveillance	I-Application
–	I-Application
Broadcast	I-Application
(	O
ADS-B	B-Application
)	O
is	O
a	O
surveillance	O
technology	O
and	O
form	O
of	O
Electronic	O
Conspicuity	O
in	O
which	O
an	O
aircraft	O
determines	O
its	O
position	O
via	O
satellite	O
navigation	O
or	O
other	O
sensors	O
and	O
periodically	O
broadcasts	O
it	O
,	O
enabling	O
it	O
to	O
be	O
tracked	O
.	O
</s>
<s>
The	O
information	O
can	O
be	O
received	O
by	O
air	B-Application
traffic	I-Application
control	I-Application
ground	O
stations	O
as	O
a	O
replacement	O
for	O
secondary	O
surveillance	O
radar	B-Application
,	O
as	O
no	O
interrogation	O
signal	O
is	O
needed	O
from	O
the	O
ground	O
.	O
</s>
<s>
It	O
can	O
also	O
be	O
transmitted	O
and	O
received	O
point-to-point	B-Architecture
by	O
other	O
aircraft	O
to	O
provide	O
situational	O
awareness	O
and	O
allow	O
self-separation	O
.	O
</s>
<s>
ADS-B	B-Application
is	O
"	O
automatic	O
"	O
in	O
that	O
it	O
requires	O
no	O
pilot	O
or	O
external	O
input	O
.	O
</s>
<s>
ADS-B	B-Application
is	O
being	O
incorporated	O
in	O
various	O
jurisdictions	O
worldwide	O
.	O
</s>
<s>
It	O
is	O
an	O
element	O
of	O
the	O
United	O
States	O
Next	O
Generation	O
Air	O
Transportation	O
System	O
(	O
NextGen	O
)	O
,	O
the	O
Airports	O
Authority	O
of	O
India	O
upgrade	O
plans	O
in	O
line	O
with	O
the	O
ICAO	B-General_Concept
Global	O
Plan	O
Initiatives	O
and	O
Aviation	B-Application
System	I-Application
Block	O
Upgrade	O
(	O
ASBU	O
)	O
,	O
and	O
the	O
Single	O
European	O
Sky	O
ATM	O
Research	O
project	O
(	O
SESAR	O
)	O
.	O
</s>
<s>
ADS-B	B-Application
equipment	O
is	O
mandatory	O
for	O
instrument	O
flight	O
rules	O
(	O
IFR	O
)	O
category	O
aircraft	O
in	O
Australian	O
airspace	O
;	O
the	O
United	O
States	O
has	O
required	O
many	O
aircraft	O
(	O
including	O
all	O
commercial	O
passenger	O
carriers	O
and	O
aircraft	O
flying	O
in	O
areas	O
that	O
required	O
a	O
transponder	O
)	O
to	O
be	O
so	O
equipped	O
since	O
January	O
2020	O
;	O
and	O
,	O
the	O
equipment	O
has	O
been	O
mandatory	O
for	O
some	O
aircraft	O
in	O
Europe	O
since	O
2017	O
.	O
</s>
<s>
Canada	O
uses	O
ADS-B	B-Application
for	O
surveillance	O
in	O
remote	O
regions	O
not	O
covered	O
by	O
traditional	O
radar	B-Application
(	O
areas	O
around	O
Hudson	O
Bay	O
,	O
the	O
Labrador	O
Sea	O
,	O
Davis	O
Strait	O
,	O
Baffin	O
Bay	O
and	O
southern	O
Greenland	O
)	O
since	O
January	O
15	O
,	O
2009	O
.	O
</s>
<s>
Aircraft	O
operators	O
are	O
encouraged	O
to	O
install	O
ADS-B	B-Application
products	O
that	O
are	O
interoperable	O
with	O
US	O
and	O
European	O
standards	O
,	O
and	O
Canadian	O
air	B-Application
traffic	I-Application
controllers	I-Application
can	O
provide	O
better	O
and	O
more	O
fuel	O
efficient	O
flight	O
routes	O
when	O
operators	O
can	O
be	O
tracked	O
via	O
ADS-B	B-Application
.	O
</s>
<s>
ADS-B	B-Application
,	O
which	O
consists	O
of	O
two	O
different	O
services	O
,	O
"	O
ADS-B	B-Application
Out	O
"	O
and	O
"	O
ADS-B	B-Application
In	O
"	O
,	O
could	O
replace	O
radar	B-Application
as	O
the	O
primary	O
surveillance	O
method	O
for	O
controlling	O
aircraft	O
worldwide	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
ADS-B	B-Application
is	O
an	O
integral	O
component	O
of	O
the	O
NextGen	O
national	O
airspace	O
strategy	O
for	O
upgrading	O
and	O
enhancing	O
aviation	O
infrastructure	O
and	O
operations	O
.	O
</s>
<s>
Also	O
within	O
the	O
United	O
States	O
,	O
the	O
ADS-B	B-Application
system	O
can	O
provide	O
traffic	O
-	O
and	O
government-generated	O
graphical	O
weather	O
information	O
at	O
no	O
cost	O
through	O
TIS-B	B-General_Concept
and	O
FIS-B	O
applications	O
.	O
</s>
<s>
ADS-B	B-Application
enhances	O
safety	O
by	O
making	O
an	O
aircraft	O
visible	O
,	O
realtime	O
,	O
to	O
air	B-Application
traffic	I-Application
control	I-Application
(	O
ATC	B-Application
)	O
and	O
to	O
other	O
appropriately	O
equipped	O
ADS-B	B-Application
aircraft	O
with	O
position	O
and	O
velocity	O
data	O
transmitted	O
every	O
second	O
.	O
</s>
<s>
ADS-B	B-Application
data	O
can	O
be	O
recorded	O
and	O
downloaded	O
for	O
post-flight	O
analysis	O
.	O
</s>
<s>
ADS-B	B-Application
also	O
provides	O
the	O
data	O
infrastructure	O
for	O
inexpensive	O
flight	O
tracking	O
,	O
planning	O
,	O
and	O
dispatch	O
.	O
</s>
<s>
Using	O
"	O
ADS-B	B-Application
Out	O
"	O
,	O
each	O
aircraft	O
periodically	O
broadcasts	O
information	O
about	O
itself	O
,	O
such	O
as	O
identification	O
,	O
current	O
position	O
,	O
altitude	O
and	O
velocity	O
,	O
through	O
an	O
onboard	O
transmitter	O
.	O
</s>
<s>
ADS-B	B-Application
Out	O
provides	O
air	B-Application
traffic	I-Application
controllers	I-Application
with	O
real-time	O
position	O
information	O
that	O
is	O
,	O
in	O
most	O
cases	O
,	O
more	O
accurate	O
than	O
the	O
information	O
available	O
with	O
current	O
radar-based	O
systems	O
.	O
</s>
<s>
With	O
more	O
accurate	O
information	O
,	O
ATC	B-Application
will	O
be	O
able	O
to	O
position	O
and	O
separate	O
aircraft	O
with	O
improved	O
precision	O
and	O
timing	O
.	O
</s>
<s>
"	O
ADS-B	B-Application
In	O
"	O
is	O
the	O
reception	O
by	O
aircraft	O
of	O
FIS-B	O
and	O
TIS-B	B-General_Concept
data	O
and	O
other	O
ADS-B	B-Application
data	O
such	O
as	O
direct	O
communication	O
from	O
nearby	O
aircraft	O
.	O
</s>
<s>
The	O
ground	O
station	O
broadcast	O
data	O
is	O
typically	O
only	O
made	O
available	O
in	O
the	O
presence	O
of	O
an	O
ADS-B	B-Application
Out	O
broadcasting	O
aircraft	O
,	O
limiting	O
the	O
usefulness	O
of	O
purely	O
ADS-B	B-Application
In	O
devices	O
.	O
</s>
<s>
GPS	O
or	O
other	O
certified	O
GNSS	O
receiver	O
)	O
and	O
a	O
datalink	O
(	O
the	O
ADS-B	B-Application
unit	O
)	O
.	O
</s>
<s>
There	O
are	O
several	O
types	O
of	O
certified	O
ADS-B	B-Application
data	O
links	O
,	O
but	O
the	O
most	O
common	O
ones	O
operate	O
at	O
1090MHz	O
,	O
essentially	O
a	O
modified	O
Mode	O
S	O
transponder	O
,	O
or	O
at	O
978MHz	O
.	O
</s>
<s>
To	O
obtain	O
ADS-B	B-Application
Out	O
capability	O
at	O
1090MHz	O
,	O
user-operators	O
can	O
install	O
a	O
new	O
transponder	O
or	O
modify	O
an	O
existing	O
transponder	O
if	O
the	O
manufacturer	O
offers	O
an	O
ADS-B	B-Application
upgrade	O
(	O
plus	O
install	O
a	O
certified	O
GNSS	O
position	O
source	O
if	O
one	O
is	O
not	O
already	O
present	O
)	O
.	O
</s>
<s>
ADS-B	B-Application
provides	O
many	O
benefits	O
to	O
both	O
pilots	O
and	O
air	B-Application
traffic	I-Application
control	I-Application
that	O
improve	O
both	O
the	O
safety	O
and	O
efficiency	O
of	O
flight	O
.	O
</s>
<s>
When	O
using	O
an	O
ADS-B	B-Application
In	O
system	O
,	O
a	O
pilot	O
is	O
able	O
to	O
view	O
traffic	O
information	O
about	O
surrounding	O
aircraft	O
if	O
those	O
aircraft	O
are	O
equipped	O
with	O
ADS-B	B-Application
Out	O
.	O
</s>
<s>
In	O
addition	O
to	O
receiving	O
position	O
reports	O
from	O
ADS-B	B-Application
Out	O
participants	O
,	O
in	O
the	O
US	O
,	O
TIS-B	B-General_Concept
can	O
provide	O
position	O
reports	O
on	O
non	O
ADS-B	B-Application
Out-equipped	O
aircraft	O
if	O
suitable	O
ground	O
equipment	O
and	O
ground	O
radar	B-Application
exist	O
.	O
</s>
<s>
ADS-R	O
re-transmits	O
ADS-B	B-Application
position	O
reports	O
between	O
UAT	O
and	O
1090	O
MHz	O
frequency	O
bands	O
.	O
</s>
<s>
Aircraft	O
equipped	O
with	O
universal	O
access	O
transceiver	O
(	O
UAT	O
)	O
ADS-B	B-Application
In	O
technology	O
will	O
be	O
able	O
to	O
receive	O
weather	O
reports	O
,	O
and	O
in	O
the	O
US	O
,	O
weather	O
radar	B-Application
through	O
flight	O
information	O
service-broadcast	O
(	O
FIS-B	O
)	O
,	O
which	O
also	O
transmits	O
readable	O
flight	O
information	O
such	O
as	O
temporary	O
flight	O
restrictions	O
(	O
TFRs	O
)	O
and	O
NOTAMs	O
.	O
</s>
<s>
ADS-B	B-Application
ground	O
stations	O
are	O
significantly	O
cheaper	O
to	O
install	O
and	O
operate	O
compared	O
to	O
primary	O
and	O
secondary	O
radar	B-Application
systems	I-Application
used	O
by	O
air	B-Application
traffic	I-Application
control	I-Application
for	O
aircraft	O
separation	O
and	O
control	O
.	O
</s>
<s>
Unlike	O
some	O
alternative	O
in-flight	O
weather	O
services	O
currently	O
being	O
offered	O
commercially	O
,	O
there	O
will	O
be	O
no	O
subscription	O
fees	O
to	O
use	O
ADS-B	B-Application
services	O
or	O
its	O
various	O
benefits	O
in	O
the	O
US	O
.	O
</s>
<s>
ADS-B	B-Application
makes	O
flying	O
significantly	O
safer	O
for	O
the	O
aviation	O
community	O
by	O
providing	O
pilots	O
with	O
improved	O
situational	O
awareness	O
.	O
</s>
<s>
Pilots	O
in	O
an	O
ADS-B	B-Application
In	O
equipped	O
cockpit	O
will	O
have	O
the	O
ability	O
to	O
see	O
,	O
on	O
their	O
in-cockpit	O
flight	O
display	O
,	O
other	O
traffic	O
operating	O
in	O
the	O
airspace	O
and	O
have	O
access	O
to	O
clear	O
and	O
detailed	O
weather	O
information	O
.	O
</s>
<s>
Even	O
aircraft	O
only	O
equipped	O
with	O
ADS-B	B-Application
Out	O
will	O
benefit	O
from	O
air	B-Application
traffic	I-Application
controllers	I-Application
 '	O
ability	O
to	O
more	O
accurately	O
and	O
reliably	O
monitor	O
their	O
position	O
.	O
</s>
<s>
When	O
using	O
this	O
system	O
both	O
pilots	O
and	O
controllers	O
will	O
see	O
the	O
same	O
radar	B-Application
picture	O
.	O
</s>
<s>
Other	O
fully	O
equipped	O
aircraft	O
using	O
the	O
airspace	O
around	O
them	O
will	O
be	O
able	O
to	O
more	O
easily	O
identify	O
and	O
avoid	O
conflict	O
with	O
an	O
aircraft	O
equipped	O
with	O
ADS-B	B-Application
Out	O
.	O
</s>
<s>
With	O
ADS-B	B-Application
,	O
information	O
is	O
sent	O
to	O
aircraft	O
using	O
ADS-B	B-Application
In	O
,	O
which	O
displays	O
all	O
aircraft	O
in	O
the	O
area	O
,	O
provided	O
those	O
aircraft	O
are	O
equipped	O
with	O
ADS-B	B-Application
Out	O
.	O
</s>
<s>
ADS-B	B-Application
provides	O
better	O
surveillance	O
in	O
fringe	O
areas	O
of	O
radar	B-Application
coverage	O
.	O
</s>
<s>
ADS-B	B-Application
does	O
not	O
have	O
the	O
siting	O
limitations	O
of	O
radar	B-Application
.	O
</s>
<s>
In	O
both	O
forms	O
of	O
ADS-B	B-Application
(	O
1090ES	O
&	O
978	O
MHz	O
UAT	O
)	O
,	O
the	O
position	O
report	O
is	O
updated	O
once	O
per	O
second	O
.	O
</s>
<s>
ADS-B	B-Application
enables	O
improved	O
safety	O
by	O
providing	O
:	O
</s>
<s>
More	O
accurate	O
search	O
and	O
rescue	O
response	O
—	O
although	O
ADS-B	B-Application
can	O
transmit	O
"	O
aircraft	O
down	O
"	O
data	O
,	O
the	O
FAA	O
has	O
stated	O
that	O
there	O
is	O
no	O
intention	O
to	O
perform	O
even	O
a	O
study	O
of	O
ADS-B	B-Application
'	O
s	O
effectiveness	O
in	O
an	O
"	O
aircraft	O
down	O
"	O
situation	O
,	O
simply	O
based	O
on	O
the	O
fact	O
that	O
ADS-B	B-Application
equipment	O
has	O
no	O
requirement	O
to	O
be	O
crashworthy	O
,	O
as	O
compared	O
to	O
the	O
current	O
"	B-Device
black	I-Device
box	I-Device
"	I-Device
recorder	O
.	O
</s>
<s>
ADS-B	B-Application
was	O
demonstrated	O
to	O
the	O
Civil	O
Air	O
Patrol	O
(	O
CAP	O
)	O
in	O
March	O
2003	O
by	O
AOPA	O
via	O
flight	O
demonstrations	O
for	O
possible	O
integration	O
of	O
the	O
technology	O
in	O
CAP	O
activities	O
.	O
</s>
<s>
ADS-B	B-Application
technology	O
provides	O
a	O
more	O
accurate	O
report	O
of	O
an	O
aircraft	O
's	O
position	O
.	O
</s>
<s>
ADS-B	B-Application
enables	O
increased	O
capacity	O
and	O
efficiency	O
by	O
supporting	O
:	O
</s>
<s>
Improved	O
air	B-Application
traffic	I-Application
control	I-Application
services	O
in	O
non-radar	O
airspace	O
;	O
</s>
<s>
Use	O
of	O
ADS-B	B-Application
and	O
CDTI	O
may	O
allow	O
decreased	O
approach	O
spacing	O
at	O
certain	O
airports	O
to	O
improve	O
capacity	O
during	O
reduced-visibility	O
operations	O
when	O
visual	O
approach	O
operations	O
would	O
normally	O
be	O
terminated	O
(	O
e.g.	O
,	O
ceilings	O
less	O
than	O
MVA	O
+500	O
)	O
.	O
</s>
<s>
The	O
ADS-B	B-Application
data	O
link	O
supports	O
a	O
number	O
of	O
airborne	O
and	O
ground	O
applications	O
.	O
</s>
<s>
Traffic	O
information	O
for	O
a	O
CDTI	O
may	O
be	O
obtained	O
from	O
one	O
or	O
multiple	O
sources	O
,	O
including	O
ADS-B	B-Application
,	O
TCAS	O
,	O
and	O
TIS-B	B-General_Concept
.	O
</s>
<s>
Direct	O
air-to-air	O
transmission	O
of	O
ADS-B	B-Application
messages	O
supports	O
display	O
of	O
proximate	O
aircraft	O
on	O
a	O
CDTI	O
.	O
</s>
<s>
In	O
addition	O
to	O
traffic	O
based	O
on	O
ADS-B	B-Application
reports	O
,	O
a	O
CDTI	O
function	O
might	O
also	O
display	O
current	O
weather	O
conditions	O
,	O
terrain	O
,	O
airspace	O
structure	O
,	O
obstructions	O
,	O
detailed	O
airport	O
maps	O
,	O
and	O
other	O
information	O
relevant	O
to	O
the	O
particular	O
phase	O
of	O
flight	O
.	O
</s>
<s>
ADS-B	B-Application
is	O
seen	O
as	O
a	O
valuable	O
technology	O
to	O
enhance	O
airborne	O
collision	O
avoidance	O
system	O
(	O
ACAS	O
)	O
operation	O
.	O
</s>
<s>
Incorporation	O
of	O
ADS-B	B-Application
can	O
provide	O
benefits	O
such	O
as	O
:	O
</s>
<s>
Reducing	O
unnecessary	O
alarm	O
rate	O
by	O
incorporating	O
the	O
ADS-B	B-Application
state	O
vector	O
,	O
aircraft	O
intent	O
,	O
and	O
other	O
information	O
.	O
</s>
<s>
Eventually	O
,	O
the	O
ACAS	O
function	O
may	O
be	O
provided	O
based	O
solely	O
on	O
ADS-B	B-Application
,	O
without	O
requiring	O
active	O
interrogations	O
of	O
other	O
aircraft	O
transponders	O
.	O
</s>
<s>
Other	O
applications	O
that	O
may	O
benefit	O
from	O
ADS-B	B-Application
include	O
:	O
</s>
<s>
A	O
number	O
of	O
websites	O
use	O
crowd-sourced	O
distributed	O
networks	O
of	O
ADS-B	B-Application
receivers	O
to	O
track	O
air	B-Application
traffic	I-Application
.	O
</s>
<s>
Pilots	O
who	O
become	O
complacent	O
or	O
overconfident	O
in	O
this	O
system	O
are	O
thus	O
a	O
safety	O
problem	O
,	O
not	O
only	O
for	O
themselves	O
but	O
for	O
other	O
transponder-only	O
aircraft	O
,	O
and	O
glider	O
aircraft	O
without	O
ADS-B	B-Application
transponder	O
.	O
</s>
<s>
Glider	O
aircraft	O
often	O
use	O
the	O
FLARM	O
system	O
for	O
collision	O
avoidance	O
with	O
other	O
glider	O
aircraft	O
,	O
but	O
this	O
system	O
is	O
not	O
compatible	O
with	O
ADS-B	B-Application
.	O
</s>
<s>
Aircraft	O
with	O
ADS-B	B-Application
but	O
without	O
FLARM	O
are	O
thus	O
a	O
safety	O
risk	O
for	O
gliders	O
with	O
FLARM	O
but	O
without	O
ADS-B	B-Application
and	O
vice	O
versa	O
.	O
</s>
<s>
Some	O
aircraft	O
,	O
like	O
those	O
used	O
for	O
towing	O
gliders	O
,	O
have	O
both	O
FLARM	O
and	O
ADS-B	B-Application
transponders	O
for	O
this	O
reason	O
.	O
</s>
<s>
A	O
security	O
researcher	O
claimed	O
in	O
2012	O
that	O
ADS-B	B-Application
has	O
no	O
defence	O
against	O
being	O
interfered	O
with	O
via	O
spoofed	O
ADS-B	B-Application
messages	O
because	O
they	O
were	O
neither	O
encrypted	O
nor	O
authenticated	O
.	O
</s>
<s>
The	O
lack	O
of	O
any	O
authentication	O
within	O
the	O
standard	O
makes	O
it	O
mandatory	O
to	O
validate	O
any	O
received	O
data	O
by	O
use	O
of	O
the	O
primary	O
radar	B-Application
.	O
</s>
<s>
Because	O
the	O
content	O
of	O
ADS-B	B-Application
messages	O
is	O
not	O
encrypted	O
,	O
it	O
may	O
be	O
read	O
by	O
anybody	O
.	O
</s>
<s>
The	O
ADS-B	B-Application
system	O
has	O
three	O
main	O
components	O
:	O
1	O
)	O
ground	O
infrastructure	O
,	O
2	O
)	O
airborne	O
component	O
,	O
and	O
3	O
)	O
operating	O
procedures	O
.	O
</s>
<s>
The	O
transport	O
protocol	O
;	O
e.g.	O
,	O
VHF	B-Algorithm
(	O
VDL	B-Algorithm
mode	O
2	O
or	O
4	O
)	O
,	O
1090ES	O
,	O
or	O
978MHz	O
UAT	O
.	O
</s>
<s>
The	O
source	O
of	O
the	O
state	O
vector	O
and	O
other	O
transmitted	O
information	O
as	O
well	O
as	O
user	O
applications	O
are	O
not	O
considered	O
to	O
be	O
part	O
of	O
the	O
ADS-B	B-Application
system	O
.	O
</s>
<s>
Two	O
link	O
solutions	O
are	O
used	O
as	O
the	O
physical	O
layer	O
for	O
relaying	O
ADS-B	B-Application
position	O
reports	O
:	O
universal	O
access	O
transceiver	O
,	O
and	O
1090MHz	O
extended	B-Application
squitter	I-Application
.	O
</s>
<s>
UAT	O
is	O
intended	O
to	O
support	O
not	O
only	O
ADS-B	B-Application
,	O
but	O
also	O
flight	O
information	O
service	O
–	O
broadcast	O
(	O
FIS-B	O
)	O
,	O
traffic	B-General_Concept
information	I-General_Concept
service	I-General_Concept
–	I-General_Concept
broadcast	I-General_Concept
(	O
TIS-B	B-General_Concept
)	O
,	O
and	O
,	O
if	O
required	O
in	O
the	O
future	O
,	O
supplementary	O
ranging	O
and	O
positioning	O
capabilities	O
.	O
</s>
<s>
Aircraft	O
equipped	O
with	O
ADS-B	B-Application
In	O
technology	O
will	O
be	O
able	O
to	O
see	O
detailed	O
altitude	O
and	O
vector	O
information	O
from	O
other	O
ADS-B	B-Application
Out	O
equipped	O
aircraft	O
as	O
well	O
as	O
FIS-B	O
and	O
TIS-B	B-General_Concept
broadcasts	O
.	O
</s>
<s>
The	O
FIS-B	O
broadcast	O
will	O
allow	O
receiving	O
aircraft	O
to	O
view	O
weather	O
and	O
flight	O
service	O
information	O
including	O
AIRMETs	O
,	O
SIGMETs	O
,	O
METARs	O
,	O
SPECI	O
,	O
national	O
NEXRAD	B-Algorithm
,	O
regional	O
NEXRAD	B-Algorithm
,	O
D-NOTAMs	O
,	O
FDC-NOTAMs	O
,	O
PIREPs	O
,	O
special	O
use	O
airspace	O
status	O
,	O
terminal	O
area	O
forecasts	O
,	O
amended	O
terminal	O
aerodrome	O
forecasts	O
(	O
TAFs	O
)	O
,	O
and	O
winds	O
and	O
temperatures	O
aloft	O
forecasts	O
.	O
</s>
<s>
Aircraft	O
receiving	O
traffic	O
information	O
through	O
the	O
TIS-B	B-General_Concept
service	O
will	O
see	O
other	O
aircraft	O
in	O
a	O
manner	O
that	O
is	O
similar	O
to	O
how	O
all	O
aircraft	O
will	O
be	O
seen	O
after	O
they	O
have	O
equipped	O
by	O
2020	O
.	O
</s>
<s>
The	O
UAT	O
system	O
is	O
specifically	O
designed	O
for	O
ADS-B	B-Application
operation	O
.	O
</s>
<s>
UAT	O
is	O
also	O
the	O
first	O
link	O
to	O
be	O
certified	O
for	O
"	O
radar-like	O
"	O
ATC	B-Application
services	O
in	O
the	O
United	O
States	O
.	O
</s>
<s>
Since	O
2001	O
it	O
has	O
been	O
providing	O
en-route	O
separation	O
(	O
the	O
same	O
as	O
mosaic	O
radar	B-Application
but	O
not	O
of	O
single-site	O
sensors	O
)	O
in	O
Alaska	O
.	O
</s>
<s>
UAT	O
is	O
the	O
only	O
ADS-B	B-Application
link	O
standard	O
that	O
is	O
truly	O
bidirectional	O
:	O
UAT	O
users	O
have	O
access	O
to	O
ground-based	O
aeronautical	O
data	O
(	O
FIS-B	O
)	O
and	O
can	O
receive	O
reports	O
from	O
proximate	O
traffic	O
(	O
TIS-B	B-General_Concept
)	O
through	O
a	O
multilink	O
gateway	O
service	O
that	O
provides	O
ADS-B	B-Application
reports	O
for	O
1090ES-equipped	O
aircraft	O
and	O
non-ADS-B	O
equipped	O
radar	B-Application
traffic	O
.	O
</s>
<s>
Viable	O
ADS-B	B-Application
UAT	O
networks	O
are	O
being	O
installed	O
as	O
part	O
of	O
the	O
United	O
States	O
 '	O
NextGen	O
air	B-Application
traffic	I-Application
system	O
.	O
</s>
<s>
In	O
2002	O
the	O
Federal	O
Aviation	O
Administration	O
(	O
FAA	O
)	O
announced	O
a	O
dual	O
link	O
decision	O
using	O
the	O
1090MHz	O
extended	B-Application
squitter	I-Application
(	O
1090ES	O
)	O
link	O
for	O
air	O
carrier	O
and	O
private	O
or	O
commercial	O
operators	O
of	O
high-performance	O
aircraft	O
,	O
and	O
universal	O
access	O
transceiver	O
link	O
for	O
the	O
typical	O
general	O
aviation	O
user	O
.	O
</s>
<s>
The	O
format	O
of	O
extended	B-Application
squitter	I-Application
messages	O
has	O
been	O
codified	O
by	O
the	O
ICAO	B-General_Concept
.	O
</s>
<s>
With	O
1090ES	O
,	O
the	O
existing	O
Mode	O
S	O
transponder	O
(	O
TSO	O
C-112	O
or	O
a	O
standalone	O
1090MHz	O
transmitter	O
)	O
supports	O
a	O
message	O
type	O
known	O
as	O
the	O
extended	B-Application
squitter	I-Application
message	O
.	O
</s>
<s>
To	O
enable	O
an	O
aircraft	O
to	O
send	O
an	O
extended	B-Application
squitter	I-Application
message	O
,	O
the	O
transponder	O
is	O
modified	O
(	O
TSO	O
C-166A	O
)	O
and	O
aircraft	O
position	O
and	O
other	O
status	O
information	O
is	O
routed	O
to	O
the	O
transponder	O
.	O
</s>
<s>
ATC	B-Application
ground	O
stations	O
and	O
aircraft	O
equipped	O
with	O
traffic	O
collision	O
avoidance	O
system	O
(	O
TCAS	O
)	O
already	O
have	O
the	O
necessary	O
1090MHz	O
(	O
Mode	O
S	O
)	O
receivers	O
to	O
receive	O
these	O
signals	O
,	O
and	O
would	O
only	O
require	O
enhancements	O
to	O
accept	O
and	O
process	O
the	O
additional	O
extended	B-Application
squitter	I-Application
information	O
.	O
</s>
<s>
As	O
per	O
the	O
FAA	O
ADS-B	B-Application
link	O
decision	O
,	O
and	O
the	O
technical	O
link	O
standards	O
,	O
1090ES	O
does	O
not	O
support	O
FIS-B	O
service	O
.	O
</s>
<s>
Radar	B-Application
directly	O
measures	O
the	O
range	O
and	O
bearing	O
of	O
an	O
aircraft	O
from	O
a	O
ground-based	O
antenna	O
.	O
</s>
<s>
The	O
primary	B-Algorithm
surveillance	I-Algorithm
radar	I-Algorithm
is	O
usually	O
a	O
pulse	O
radar	B-Application
.	O
</s>
<s>
Bearing	O
is	O
measured	O
by	O
the	O
position	O
of	O
the	O
rotating	O
radar	B-Application
antenna	O
when	O
it	O
receives	O
the	O
RF	O
pulses	O
that	O
are	O
reflected	O
from	O
the	O
aircraft	O
skin	O
.	O
</s>
<s>
Primary	B-Algorithm
surveillance	I-Algorithm
radar	I-Algorithm
does	O
not	O
require	O
any	O
cooperation	O
from	O
the	O
aircraft	O
.	O
</s>
<s>
It	O
is	O
robust	O
in	O
the	O
sense	O
that	O
surveillance	O
outage	O
failure	O
modes	O
are	O
limited	O
to	O
those	O
associated	O
with	O
the	O
ground	O
radar	B-Application
system	I-Application
.	O
</s>
<s>
Secondary	O
surveillance	O
radar	B-Application
depends	O
on	O
active	O
replies	O
from	O
the	O
aircraft	O
.	O
</s>
<s>
Typical	O
ADS-B	B-Application
aircraft	O
installations	O
use	O
the	O
output	O
of	O
the	O
navigation	O
unit	O
for	O
navigation	O
and	O
for	O
cooperative	O
surveillance	O
,	O
introducing	O
a	O
common	O
failure	O
mode	O
that	O
must	O
be	O
accommodated	O
in	O
air	B-Application
traffic	I-Application
surveillance	O
systems	O
.	O
</s>
<s>
Additionally	O
,	O
detecting	O
changes	O
in	O
aircraft	O
velocity	O
requires	O
several	O
radar	B-Application
sweeps	O
that	O
are	O
spaced	O
several	O
seconds	O
apart	O
.	O
</s>
<s>
In	O
contrast	O
,	O
a	O
system	O
using	O
ADS-B	B-Application
creates	O
and	O
listens	O
for	O
periodic	O
position	O
and	O
intent	O
reports	O
from	O
aircraft	O
.	O
</s>
<s>
These	O
reports	O
are	O
generated	O
based	O
on	O
the	O
aircraft	O
's	O
navigation	O
system	O
,	O
and	O
distributed	O
via	O
one	O
or	O
more	O
of	O
the	O
ADS-B	B-Application
data	O
links	O
.	O
</s>
<s>
The	O
accuracy	O
of	O
the	O
data	O
is	O
no	O
longer	O
susceptible	O
to	O
the	O
position	O
of	O
the	O
aircraft	O
or	O
the	O
length	O
of	O
time	O
between	O
radar	B-Application
sweeps	O
.	O
</s>
<s>
Today	O
's	O
air	B-Application
traffic	I-Application
control	I-Application
(	O
ATC	B-Application
)	O
systems	O
do	O
not	O
rely	O
on	O
coverage	O
by	O
a	O
single	O
radar	B-Application
.	O
</s>
<s>
Instead	O
a	O
multiradar	O
picture	O
is	O
presented	O
via	O
the	O
ATC	B-Application
system	O
's	O
display	O
to	O
the	O
controller	B-Application
.	O
</s>
<s>
This	O
improves	O
the	O
quality	O
of	O
the	O
reported	O
position	O
of	O
the	O
aircraft	O
,	O
provides	O
a	O
measure	O
of	O
redundancy	O
,	O
and	O
makes	O
it	O
possible	O
to	O
verify	O
the	O
output	O
of	O
the	O
different	O
radars	B-Application
against	O
others	O
.	O
</s>
<s>
This	O
verification	O
can	O
also	O
use	O
sensor	O
data	O
from	O
other	O
technologies	O
,	O
such	O
as	O
ADS-B	B-Application
and	O
multilateration	O
.	O
</s>
<s>
ADS-A	O
is	O
based	O
on	O
a	O
negotiated	O
one-to-one	B-Architecture
peer	O
relationship	O
between	O
an	O
aircraft	O
providing	O
ADS	O
information	O
and	O
a	O
ground	O
facility	O
requiring	O
receipt	O
of	O
ADS	O
messages	O
.	O
</s>
<s>
For	O
example	O
,	O
ADS-A	O
reports	O
are	O
employed	O
in	O
the	O
Future	O
Air	O
Navigation	O
System	O
(	O
FANS	O
)	O
using	O
the	O
Aircraft	B-Algorithm
Communications	I-Algorithm
Addressing	I-Algorithm
and	I-Algorithm
Reporting	I-Algorithm
System	I-Algorithm
(	O
ACARS	B-Algorithm
)	O
as	O
the	O
communication	O
protocol	O
.	O
</s>
<s>
During	O
flight	O
over	O
areas	O
without	O
radar	B-Application
coverage	O
,	O
e.g.	O
,	O
oceanic	O
and	O
polar	O
,	O
reports	O
are	O
periodically	O
sent	O
by	O
an	O
aircraft	O
to	O
the	O
controlling	O
air	B-Application
traffic	I-Application
region	O
.	O
</s>
<s>
Traffic	B-General_Concept
information	I-General_Concept
service	I-General_Concept
–	I-General_Concept
broadcast	I-General_Concept
(	O
TIS	O
–	O
B	O
)	O
supplements	O
ADS-B	B-Application
'	O
s	O
air-to-air	O
services	O
to	O
provide	O
complete	O
situational	O
awareness	O
in	O
the	O
cockpit	O
of	O
all	O
traffic	O
known	O
to	O
the	O
ATC	B-Application
system	O
.	O
</s>
<s>
TIS	O
–	O
B	O
is	O
an	O
important	O
service	O
for	O
an	O
ADS-B	B-Application
link	O
in	O
airspace	O
where	O
not	O
all	O
aircraft	O
are	O
transmitting	O
ADS-B	B-Application
information	O
.	O
</s>
<s>
The	O
ground	O
TIS	O
–	O
B	O
station	O
transmits	O
surveillance	O
target	O
information	O
on	O
the	O
ADS-B	B-Application
data	O
link	O
for	O
unequipped	O
targets	O
or	O
targets	O
transmitting	O
only	O
on	O
another	O
ADS-B	B-Application
link	O
.	O
</s>
<s>
The	O
multilink	O
gateway	O
service	O
is	O
a	O
companion	O
to	O
TIS-B	B-General_Concept
for	O
achieving	O
interoperability	O
between	O
different	O
aircraft	O
equipped	O
with	O
1090ES	O
or	O
UAT	O
by	O
using	O
ground-based	O
relay	O
stations	O
.	O
</s>
<s>
These	O
aircraft	O
cannot	O
directly	O
share	O
air-to-air	O
ADS-B	B-Application
data	O
due	O
to	O
the	O
different	O
communication	O
frequencies	O
.	O
</s>
<s>
In	O
terminal	O
areas	O
,	O
where	O
both	O
types	O
of	O
ADS-B	B-Application
link	O
are	O
in	O
use	O
,	O
ADS-B/TIS	O
-B	O
ground	O
stations	O
use	O
ground-to-air	O
broadcasts	O
to	O
relay	O
ADS-B	B-Application
reports	O
received	O
on	O
one	O
link	O
to	O
aircraft	O
using	O
the	O
other	O
link	O
.	O
</s>
<s>
Since	O
two	O
aircraft	O
on	O
two	O
different	O
ADS-B	B-Application
frequencies	O
must	O
use	O
a	O
ground	O
station	O
to	O
talk	O
to	O
each	O
other	O
,	O
this	O
introduces	O
the	O
ground	O
station	O
as	O
a	O
point	O
of	O
failure	O
,	O
although	O
to	O
be	O
fair	O
,	O
the	O
1090	O
signal	O
is	O
dependent	O
secondary	O
radar	B-Application
scans	O
in	O
any	O
case	O
(	O
and	O
thus	O
cannot	O
operate	O
without	O
a	O
ground	O
station	O
)	O
.	O
</s>
<s>
This	O
contrasts	O
with	O
two	O
autonomous	O
ADS-B	B-Application
transceivers	O
on	O
UAT	O
,	O
which	O
have	O
a	O
shorter	O
and	O
shorter	O
delay	O
as	O
they	O
converge	O
.	O
</s>
<s>
Aircraft	O
are	O
frequently	O
out	O
of	O
the	O
range	O
of	O
ground	O
based	O
radar	B-Application
due	O
to	O
altitude	O
.	O
</s>
<s>
Radar	B-Application
can	O
be	O
blocked	O
by	O
mountains	O
,	O
and	O
typically	O
is	O
not	O
useful	O
for	O
coverage	O
near	O
an	O
airport	O
unless	O
that	O
airport	O
has	O
radar	B-Application
.	O
</s>
<s>
Because	O
of	O
the	O
issues	O
with	O
multilink	O
,	O
many	O
ADS-B	B-Application
manufacturers	O
are	O
designing	O
ADS-B	B-Application
systems	O
as	O
dual-frequency	O
capable	O
.	O
</s>
<s>
FIS-B	O
is	O
inherently	O
different	O
from	O
ADS-B	B-Application
in	O
that	O
it	O
requires	O
sources	O
of	O
data	O
external	O
to	O
the	O
aircraft	O
or	O
broadcasting	O
unit	O
,	O
and	O
has	O
different	O
performance	O
requirements	O
such	O
as	O
periodicity	O
of	O
broadcast	O
.	O
</s>
<s>
ADS-B	B-Application
equipment	O
is	O
mandatory	O
for	O
all	O
aircraft	O
flying	O
at	O
this	O
altitude	O
.	O
</s>
<s>
To	O
achieve	O
this	O
level	O
of	O
coverage	O
Airservices	O
Australia	O
operates	O
more	O
than	O
70	O
ADS-B	B-Application
ground	O
receiver	O
sites	O
.	O
</s>
<s>
In	O
Australia	O
the	O
aviation	O
regulator	O
,	O
the	O
Civil	O
Aviation	O
Safety	O
Authority	O
,	O
mandated	O
a	O
phased	O
requirement	O
for	O
all	O
Instrument	O
Flight	O
Rules	O
(	O
IFR	O
)	O
aircraft	O
to	O
be	O
equipped	O
with	O
ADS-B	B-Application
Out	O
by	O
2	O
February	O
2017	O
.	O
</s>
<s>
Nav	O
Canada	O
commissioned	O
operational	O
use	O
of	O
ADS-B	B-Application
in	O
2009	O
and	O
is	O
now	O
using	O
it	O
to	O
provide	O
coverage	O
of	O
its	O
northern	O
airspace	O
around	O
Hudson	O
Bay	O
,	O
most	O
of	O
which	O
currently	O
has	O
no	O
radar	B-Application
coverage	O
.	O
</s>
<s>
In	O
2018	O
,	O
Nav	O
Canada	O
issued	O
an	O
aeronautical	O
study	O
proposing	O
a	O
mandate	O
for	O
Aireon-compatible	O
ADS-B	B-Application
Out	O
for	O
all	O
aircraft	O
in	O
Class	O
A	O
Airspace	O
by	O
2021	O
and	O
Class	O
B	O
Airspace	O
by	O
2022	O
,	O
requiring	O
a	O
transponder	O
capable	O
of	O
delivering	O
antenna	O
diversity	O
performance	O
.	O
</s>
<s>
In	O
May	O
2021	O
,	O
the	O
not-for-profit	O
announced	O
its	O
intention	O
to	O
build	O
and	O
operate	O
a	O
network	O
broadcasting	O
FIS-B	O
(	O
weather	O
)	O
and	O
TIS-B	B-General_Concept
(	O
traffic	O
)	O
information	O
on	O
978MHz	O
.	O
</s>
<s>
Aircraft	O
can	O
use	O
the	O
same	O
ADS-B	B-Application
In	O
receivers	O
in	O
both	O
countries	O
and	O
the	O
provided	O
services	O
operate	O
seamlessly	O
when	O
crossing	O
the	O
border	O
.	O
</s>
<s>
An	O
American	O
company	O
ADS-B	B-Application
Technologies	O
created	O
one	O
of	O
the	O
largest	O
and	O
most	O
successful	O
ADS-B	B-Application
systems	O
in	O
the	O
world	O
(	O
an	O
eight-station	O
,	O
350+	O
aircraft	O
network	O
that	O
spans	O
more	O
than	O
1,200	O
nmi	O
across	O
Central	O
China	O
)	O
.	O
</s>
<s>
As	O
of	O
March	O
2009	O
,	O
more	O
than	O
1.2million	O
incident/failure	O
free	O
flight	O
hours	O
have	O
been	O
flown	O
with	O
these	O
ADS-B	B-Application
systems	O
.	O
</s>
<s>
As	O
of	O
2010	O
,	O
Isavia	O
is	O
in	O
the	O
process	O
of	O
installing	O
ADS-B	B-Application
across	O
the	O
North	O
Atlantic	O
Ocean	O
.	O
</s>
<s>
The	O
Airports	O
Authority	O
of	O
India	O
(	O
AAI	O
)	O
,	O
which	O
manages	O
the	O
country	O
's	O
airspace	O
,	O
first	O
commissioned	O
German	O
company	O
Comsoft	O
to	O
install	O
ADS-B	B-Application
ground	O
stations	O
at	O
14	O
airport	O
sites	O
nationwide	O
in	O
2012	O
.	O
</s>
<s>
Comsoft	O
finished	O
installing	O
seven	O
new	O
ADS-B	B-Application
ground	O
stations	O
under	O
a	O
second	O
phase	O
of	O
deployment	O
which	O
India	O
subsequently	O
integrated	O
into	O
its	O
ATC	B-Application
system	O
in	O
2014	O
,	O
thus	O
completing	O
its	O
ground	O
network	O
for	O
automatic	B-Application
dependent	I-Application
surveillance-broadcast	I-Application
(	O
ADS-B	B-Application
)	O
tracking	O
of	O
aircraft	O
.	O
</s>
<s>
In	O
line	O
with	O
the	O
International	B-General_Concept
Civil	I-General_Concept
Aviation	I-General_Concept
Organization	I-General_Concept
's	O
aviation	B-Application
system	I-Application
block	O
upgrade	O
plan	O
,	O
AAI	O
has	O
said	O
that	O
its	O
ADS-B	B-Application
network	O
will	O
provide	O
redundant	O
,	O
satellite-based	O
surveillance	O
where	O
radar	B-Application
coverage	O
exists	O
,	O
fill	O
gaps	O
in	O
surveillance	O
where	O
radar	B-Application
coverage	O
is	O
not	O
possible	O
due	O
to	O
high	O
terrain	O
or	O
remote	O
airspace	O
and	O
enable	O
it	O
to	O
share	O
ADS-B	B-Application
data	O
with	O
neighboring	O
countries	O
.	O
</s>
<s>
An	O
ADS-B	B-Application
–	O
supported	O
system	O
is	O
planned	O
for	O
operational	O
usage	O
in	O
Kiruna	O
,	O
Sweden	O
,	O
during	O
spring	O
2009	O
.	O
</s>
<s>
Based	O
on	O
the	O
VDL	B-Algorithm
Mode4	O
standards	O
,	O
the	O
network	O
of	O
ground	O
stations	O
can	O
support	O
services	O
for	O
ADS-B	B-Application
,	O
TIS-B	B-General_Concept
,	O
FIS-B	O
,	O
GNS-B	O
(	O
DGNSS	O
augmentation	O
)	O
and	O
point-to-point	B-Architecture
communication	I-Architecture
,	O
allowing	O
aircraft	O
equipped	O
with	O
VDL4-compliant	O
transceivers	O
to	O
lower	O
fuel	O
consumption	O
and	O
reduce	O
flight	O
times	O
.	O
</s>
<s>
United	O
Arab	O
Emirates	O
commissioned	O
three	O
operational	O
redundant	O
ADS-B	B-Application
ground	O
stations	O
in	O
early	O
2009	O
and	O
is	O
now	O
using	O
ADS-B	B-Application
to	O
provide	O
enhanced	O
coverage	O
of	O
its	O
upper	O
airspace	O
in	O
combination	O
and	O
integrated	O
with	O
conventional	O
surveillance	O
radars	B-Application
.	O
</s>
<s>
To	O
reduce	O
congestion	O
and	O
cope	O
with	O
growing	O
aircraft	B-Application
traffic	I-Application
,	O
the	O
Federal	O
Aviation	O
Administration	O
has	O
been	O
developing	O
the	O
Next-Generation	O
Air	O
Transportation	O
System	O
(	O
NextGen	O
)	O
,	O
including	O
ADS-B	B-Application
.	O
</s>
<s>
ADS-B	B-Application
equipment	O
is	O
built	O
to	O
meet	O
one	O
of	O
two	O
sets	O
of	O
industry	O
standards	O
,	O
DO-260B	O
and	O
DO-282B	O
.	O
</s>
<s>
Aircraft	O
operating	O
in	O
the	O
United	O
States	O
in	O
the	O
airspace	O
classes	O
listed	O
below	O
are	O
required	O
to	O
carry	O
equipment	O
that	O
produces	O
an	O
ADS-B	B-Application
Out	O
broadcast	O
.	O
</s>
<s>
ADS-B	B-Application
Out	O
broadcasts	O
information	O
about	O
an	O
aircraft	O
through	O
an	O
onboard	O
transmitter	O
to	O
a	O
ground	O
receiver	O
,	O
moving	O
air	B-Application
traffic	I-Application
control	I-Application
from	O
a	O
radar-based	O
system	O
to	O
a	O
satellite-derived	O
aircraft	O
location	O
system	O
.	O
</s>
<s>
There	O
is	O
no	O
such	O
mandate	O
for	O
ADS-B	B-Application
In	O
,	O
which	O
receives	O
data	O
and	O
provides	O
it	O
to	O
in-cockpit	O
displays	O
.	O
</s>
<s>
Operators	O
can	O
choose	O
the	O
1090megahertz	O
extended	B-Application
squitter	I-Application
broadcast	O
link	O
,	O
or	O
the	O
universal	O
access	O
transceiver	O
broadcast	O
link	O
.	O
</s>
<s>
FAA	O
did	O
not	O
adopt	O
higher	O
performance	O
standards	O
that	O
would	O
enable	O
all	O
of	O
the	O
initial	O
ADS-B	B-Application
In	O
applications	O
,	O
but	O
these	O
can	O
optionally	O
be	O
adopted	O
.	O
</s>
<s>
Fleet	O
:	O
250,000	O
GA	O
aircraft	O
that	O
will	O
need	O
ADS-B	B-Application
by	O
2020	O
of	O
which	O
165,000	O
aircraft	O
subject	O
to	O
ADS-B	B-Application
Out	O
(	O
Class	O
I	O
and	O
Class	O
II	O
aircraft	O
that	O
generally	O
fly	O
below	O
18	O
000feet	O
)	O
.	O
</s>
<s>
The	O
Federal	O
Aviation	O
Administration	O
ADS-B	B-Application
implementation	O
is	O
broken	O
into	O
three	O
segments	O
each	O
with	O
a	O
corresponding	O
time	O
line	O
.	O
</s>
<s>
The	O
cost	O
to	O
equip	O
with	O
ADS-B	B-Application
Out	O
capability	O
is	O
relatively	O
small	O
and	O
would	O
benefit	O
the	O
airspace	O
with	O
surveillance	O
in	O
areas	O
not	O
currently	O
served	O
by	O
radar	B-Application
.	O
</s>
<s>
The	O
FAA	O
intends	O
to	O
provide	O
similar	O
service	O
within	O
the	O
NAS	O
to	O
what	O
radar	B-Application
is	O
currently	O
providing	O
(	O
5nmi	O
en	O
route	O
and	O
3nmi	O
terminal	O
radar	B-Application
standards	O
)	O
as	O
a	O
first	O
step	O
to	O
implementation	O
.	O
</s>
<s>
However	O
,	O
ADS-B	B-Application
In	O
capability	O
is	O
viewed	O
as	O
the	O
most	O
likely	O
way	O
to	O
improve	O
NAS	O
throughput	O
and	O
enhance	O
capacity	O
.	O
</s>
<s>
In	O
December	O
2008	O
,	O
Acting	O
FAA	O
Administrator	O
Robert	O
A	O
.	O
Sturgell	O
gave	O
the	O
go-ahead	O
for	O
ADS-B	B-Application
to	O
go	O
live	O
in	O
southern	O
Florida	O
.	O
</s>
<s>
ADS-B	B-Application
deployment	O
and	O
voluntary	O
equipment	O
,	O
along	O
with	O
rule-making	O
activities	O
.	O
</s>
<s>
Pockets	O
of	O
development	O
will	O
exploit	O
equipment	O
deployment	O
in	O
the	O
areas	O
that	O
will	O
provide	O
proof	O
of	O
concept	O
for	O
integration	O
to	O
ATC	B-Application
automation	O
systems	O
deployed	O
in	O
the	O
NAS	O
.	O
</s>
<s>
ADS-B	B-Application
ground	O
stations	O
will	O
be	O
deployed	O
throughout	O
the	O
NAS	O
,	O
with	O
an	O
in-service	O
decision	O
due	O
in	O
the	O
2012	O
–	O
2013	O
time	O
frame	O
.	O
</s>
<s>
Airport	O
situational	O
awareness	O
—	O
a	O
combination	O
of	O
detailed	O
airport	O
maps	O
,	O
airport	O
multilateration	O
systems	O
,	O
ADS-B	B-Application
systems	O
and	O
enhanced	O
aircraft	O
displays	O
have	O
the	O
potential	O
to	O
significantly	O
improve	O
Airport	O
Surface	O
Situational	O
Awareness	O
(	O
ASSA	O
)	O
,	O
and	O
Final	O
Approach	O
and	O
Runway	O
Occupancy	O
Awareness	O
(	O
FAROA	O
)	O
.	O
</s>
<s>
Oceanic	O
In-trail	O
—	O
ADS-B	B-Application
may	O
provide	O
enhanced	O
situational	O
awareness	O
and	O
safety	O
for	O
Oceanic	O
In-trail	O
maneuvers	O
as	O
additional	O
aircraft	O
become	O
equipped	O
.	O
</s>
<s>
Gulf	O
of	O
Mexico	O
—	O
in	O
the	O
Gulf	O
of	O
Mexico	O
,	O
where	O
ATC	B-Application
radar	B-Application
coverage	O
is	O
incomplete	O
,	O
the	O
FAA	O
is	O
locating	O
ADS-B	B-Application
(	O
1090MHz	O
)	O
receivers	O
on	O
oil	O
rigs	O
to	O
relay	O
information	O
received	O
from	O
aircraft	O
equipped	O
with	O
ADS-B	B-Application
extended	B-Application
squitters	I-Application
back	O
to	O
the	O
Houston	O
Center	O
to	O
expand	O
and	O
improve	O
surveillance	O
coverage	O
.	O
</s>
<s>
Terminal	O
Airspace	O
—	O
ADS-B	B-Application
is	O
currently	O
in	O
service	O
for	O
two	O
terminal	O
airspace	O
areas	O
,	O
Louisville	O
,	O
Kentucky	O
,	O
and	O
Philadelphia	O
,	O
Pennsylvania	O
.	O
</s>
<s>
Limited	O
radar	B-Application
decommissioning	O
will	O
begin	O
in	O
the	O
time	O
frame	O
with	O
an	O
ultimate	O
goal	O
of	O
a	O
50%	O
reduction	O
in	O
the	O
secondary	O
surveillance	O
radar	B-Application
infrastructure	O
.	O
</s>
<s>
On	O
27	O
May	O
2010	O
,	O
the	O
FAA	O
published	O
its	O
final	O
rule	O
mandating	O
that	O
by	O
2020	O
all	O
aircraft	O
owners	O
will	O
be	O
required	O
to	O
have	O
ADS-B	B-Application
Out	O
capabilities	O
when	O
operating	O
in	O
any	O
airspace	O
that	O
currently	O
requires	O
a	O
transponder	O
(	O
airspace	O
classes	O
A	O
,	O
B	O
,	O
and	O
C	O
,	O
and	O
airspace	O
classE	O
at	O
certain	O
altitudes	O
)	O
.	O
</s>
<s>
On	O
14	O
June	O
2012	O
,	O
FreeFlight	O
Systems	O
and	O
Chevron	O
received	O
STC	O
for	O
first	O
rule-compliant	O
ADS-B	B-Application
installation	O
in	O
GOMEX	O
helicopters	O
that	O
was	O
awarded	O
by	O
the	O
FAA	O
.	O
</s>
<s>
The	O
benefits	O
to	O
the	O
carrier	O
are	O
fuel	O
and	O
time	O
efficiencies	O
associated	O
with	O
idle	O
descent	O
and	O
shorter	O
traffic	O
patterns	O
than	O
typical	O
radar	B-Application
vectoring	O
allows	O
.	O
</s>
<s>
Embry-Riddle	O
Aeronautical	O
University	O
ERAU	O
has	O
equipped	O
their	O
training	O
aircraft	O
at	O
its	O
two	O
main	O
campuses	O
in	O
Florida	O
and	O
Arizona	O
with	O
UAT	O
ADS-B	B-Application
capability	O
as	O
a	O
situational	O
safety	O
enhancement	O
.	O
</s>
<s>
With	O
the	O
addition	O
of	O
the	O
Garmin	O
G1000	O
flight	O
instrument	O
system	O
to	O
their	O
fleet	O
in	O
2006	O
,	O
ERAU	O
became	O
the	O
first	O
fleet	O
to	O
combine	O
a	O
glass	O
cockpit	O
with	O
ADS-B	B-Application
.	O
</s>
<s>
University	O
of	O
North	O
Dakota	O
UND	O
has	O
received	O
an	O
FAA	O
grant	O
to	O
test	O
ADS-B	B-Application
,	O
and	O
has	O
begun	O
to	O
outfit	O
their	O
Piper	O
Warrior	O
fleet	O
with	O
an	O
ADS-B	B-Application
package	O
.	O
</s>
<s>
Privacy	O
ICAO	B-General_Concept
Aircraft	O
(	O
PIA	O
)	O
:	O
Program	O
to	O
improve	O
the	O
privacy	O
of	O
eligible	O
aircraft	O
by	O
enabling	O
aircraft	O
owners	O
to	O
request	O
an	O
alternate	O
,	O
temporary	O
ICAO	B-General_Concept
aircraft	O
address	O
,	O
which	O
will	O
not	O
be	O
assigned	O
to	O
the	O
owner	O
in	O
the	O
Civil	O
Aviation	O
Registry	O
(	O
CAR	O
)	O
.	O
</s>
<s>
A	O
concern	O
for	O
any	O
ADS-B	B-Application
protocol	O
is	O
the	O
capacity	O
for	O
carrying	O
ADS-B	B-Application
messages	O
from	O
aircraft	O
,	O
as	O
well	O
as	O
allowing	O
the	O
radio	O
channel	O
to	O
continue	O
to	O
support	O
any	O
legacy	O
services	O
.	O
</s>
<s>
For	O
1090ES	O
,	O
each	O
ADS-B	B-Application
message	O
is	O
composed	O
of	O
a	O
pair	O
of	O
data	B-Protocol
packets	I-Protocol
.	O
</s>
<s>
The	O
greater	O
the	O
number	O
of	O
packets	B-Protocol
transmitted	O
from	O
one	O
aircraft	O
,	O
the	O
fewer	O
aircraft	O
that	O
can	O
participate	O
in	O
the	O
system	O
,	O
due	O
to	O
the	O
fixed	O
and	O
limited	O
channel	O
data	O
bandwidth	B-Algorithm
.	O
</s>
<s>
For	O
1090ES	O
,	O
both	O
TCAS	O
and	O
ATCRBS/MSSR	O
are	O
existing	O
users	O
of	O
the	O
channel	O
.	O
</s>
<s>
1090ES	O
ADS-B	B-Application
must	O
not	O
reduce	O
capacity	O
of	O
these	O
existing	O
systems	O
.	O
</s>
<s>
The	O
FAA	O
national	O
program	O
office	O
and	O
other	O
international	O
aviation	O
regulators	O
are	O
addressing	O
concerns	O
about	O
ADS-B	B-Application
non-secure	O
nature	O
of	O
ADS-B	B-Application
transmissions	O
.	O
</s>
<s>
ADS-B	B-Application
messages	O
can	O
be	O
used	O
to	O
know	O
the	O
location	O
of	O
an	O
aircraft	O
,	O
and	O
there	O
is	O
no	O
means	O
to	O
guarantee	O
that	O
this	O
information	O
is	O
not	O
used	O
inappropriately	O
.	O
</s>
<s>
Additionally	O
,	O
there	O
are	O
some	O
concerns	O
about	O
the	O
integrity	O
of	O
ADS-B	B-Application
transmissions	O
.	O
</s>
<s>
ADS-B	B-Application
messages	O
can	O
be	O
produced	O
,	O
with	O
simple	O
,	O
low-cost	O
measures	O
,	O
which	O
spoof	O
the	O
locations	O
of	O
multiple	O
phantom	O
aircraft	O
to	O
disrupt	O
safe	O
air	O
travel	O
.	O
</s>
<s>
This	O
problem	O
is	O
however	O
similar	O
to	O
the	O
usage	O
of	O
ATCRBS/MSSR	O
where	O
false	O
signals	O
also	O
are	O
potentially	O
dangerous	O
(	O
uncorrelated	O
secondary	O
tracks	O
)	O
.	O
</s>
<s>
There	O
are	O
some	O
concerns	O
about	O
ADS-B	B-Application
dependence	O
on	O
satellite	O
navigation	O
systems	O
to	O
generate	O
state	O
vector	O
information	O
,	O
although	O
the	O
risks	O
can	O
be	O
mitigated	O
by	O
using	O
redundant	O
sources	O
of	O
state	O
vector	O
information	O
;	O
e.g.	O
,	O
GPS	O
,	O
GLONASS	O
,	O
Galileo	O
or	O
multilateration	O
.	O
</s>
<s>
There	O
are	O
some	O
general	O
aviation	O
concerns	O
that	O
ADS-B	B-Application
removes	O
anonymity	O
of	O
the	O
VFR	O
aircraft	O
operations	O
.	O
</s>
<s>
The	O
ICAO	B-General_Concept
24-bit	O
transponder	O
code	O
specifically	O
assigned	O
to	O
each	O
aircraft	O
will	O
allow	O
monitoring	O
of	O
that	O
aircraft	O
when	O
within	O
the	O
service	O
volumes	O
of	O
the	O
Mode-S/ADS	O
-B	O
system	O
.	O
</s>
<s>
Mode-S/ADS	O
-B	O
identifies	O
the	O
aircraft	O
uniquely	O
among	O
all	O
in	O
the	O
world	O
,	O
in	O
a	O
similar	O
fashion	O
as	O
a	O
MAC	O
number	O
for	O
an	O
Ethernet	O
card	O
or	O
the	O
International	O
Mobile	O
Equipment	O
Identity	O
(	O
IMEI	O
)	O
of	O
a	O
GSM	O
phone	O
.	O
</s>
<s>
However	O
,	O
the	O
FAA	O
is	O
allowing	O
UAT-equipped	O
aircraft	O
to	O
utilize	O
a	O
random	O
self-assigned	O
temporary	O
ICAO	B-General_Concept
address	O
in	O
conjunction	O
with	O
the	O
use	O
of	O
beacon	O
code	O
1200	O
.	O
</s>
<s>
1090ES	O
equipped	O
aircraft	O
using	O
ADS-B	B-Application
will	O
not	O
have	O
this	O
option	O
.	O
</s>
<s>
In	O
order	O
for	O
the	O
ADS-B	B-Application
system	O
to	O
function	O
to	O
the	O
fullest	O
extent	O
,	O
equipage	O
into	O
all	O
aircraft	O
in	O
the	O
airspace	O
is	O
required	O
.	O
</s>
<s>
The	O
requirements	O
for	O
these	O
smaller	O
and	O
lighter	O
aircraft	O
are	O
mainly	O
size	O
,	O
weight	O
,	O
and	O
power	O
(	O
SWAP	O
)	O
and	O
transponder	O
technology	O
must	O
allow	O
for	O
equipage	O
of	O
these	O
types	O
of	O
aircraft	O
to	O
enable	O
saturation	O
of	O
ADS-B	B-Application
for	O
total	O
visibility	O
in	O
any	O
given	O
airspace	O
.	O
</s>
<s>
On	O
7	O
June	O
2002	O
the	O
FAA	O
published	O
a	O
historical	O
overview	O
of	O
its	O
decision	O
on	O
the	O
ADS-B	B-Application
link	O
architecture	O
for	O
use	O
in	O
the	O
National	O
Airspace	O
System	O
(	O
NAS	O
)	O
.	O
</s>
<s>
DO-242A	O
—	O
ADS-B	B-Application
MASPS	O
.	O
</s>
<s>
Describes	O
system-wide	O
operational	O
use	O
of	O
ADS-B	B-Application
.	O
</s>
<s>
A	O
significant	O
step	O
forward	O
for	O
ADS-B	B-Application
is	O
the	O
reception	O
by	O
artificial	O
satellites	O
of	O
the	O
ADS-B	B-Application
signal	O
.	O
</s>
<s>
Aireon	O
is	O
also	O
working	O
on	O
space-based	O
ADS-B	B-Application
with	O
the	O
Iridium	O
satellite	O
network	O
,	O
a	O
LEO	O
(	O
Low	O
Earth	O
Orbit	O
)	O
satellite	O
network	O
that	O
was	O
originally	O
created	O
to	O
deliver	O
phone	O
and	O
data	O
service	O
anywhere	O
on	O
the	O
planet	O
.	O
</s>
<s>
By	O
capturing	O
ADS-B	B-Application
position	O
data	O
from	O
aircraft	O
flying	O
below	O
the	O
satellite	O
,	O
the	O
network	O
will	O
give	O
the	O
following	O
capabilities	O
:	O
</s>
<s>
Air	B-Application
traffic	I-Application
control	I-Application
using	O
surveillance	O
based	O
separation	O
standards	O
will	O
be	O
possible	O
over	O
water	O
,	O
in	O
areas	O
that	O
radar	B-Application
does	O
not	O
currently	O
cover	O
.	O
</s>
<s>
Currently	O
,	O
air	B-Application
traffic	I-Application
control	I-Application
uses	O
the	O
larger	O
procedural	O
separation	O
standard	O
in	O
oceanic	O
and	O
remote	O
areas	O
.	O
</s>
<s>
As	O
is	O
currently	O
possible	O
in	O
radar	B-Application
covered	O
areas	O
,	O
a	O
position	O
history	O
will	O
be	O
available	O
for	O
lost	O
aircraft	O
,	O
as	O
in	O
the	O
case	O
of	O
Malaysia	O
Airlines	O
Flight	O
370	O
.	O
</s>
<s>
The	O
system	O
only	O
receives	O
ADS-B	B-Application
on	O
aircraft	O
broadcasting	O
on	O
the	O
1090MHz	O
frequency	O
.	O
</s>
<s>
This	O
limits	O
the	O
system	O
generally	O
to	O
airliners	O
and	O
business	O
aircraft	O
,	O
despite	O
the	O
fact	O
that	O
small	O
aircraft	O
are	O
frequently	O
off	O
radar	B-Application
due	O
to	O
mountains	O
blocking	O
the	O
signal	O
at	O
low	O
altitudes	O
.	O
</s>
<s>
The	O
system	O
could	O
be	O
compromised	O
by	O
smaller	O
,	O
private	O
aircraft	O
with	O
exclusively	O
belly	O
mounted	O
ADS-B	B-Application
antennas	O
,	O
due	O
to	O
the	O
aircraft	O
hull	O
blocking	O
the	O
signal	O
.	O
</s>
<s>
The	O
Iridium	O
satellites	O
fly	O
very	O
low	O
,	O
and	O
thus	O
can	O
receive	O
the	O
ADS-B	B-Application
out	O
signals	O
more	O
reliably	O
(	O
transponders	O
and	O
ADS-B	B-Application
were	O
designed	O
for	O
ground	O
reception	O
)	O
.	O
</s>
<s>
In	O
September	O
2016	O
,	O
Aireon	O
and	O
FlightAware	B-Application
announced	O
a	O
partnership	O
to	O
provide	O
this	O
global	O
space-based	O
ADS-B	B-Application
data	O
to	O
airlines	O
for	O
flight	O
tracking	O
of	O
their	O
fleets	O
and	O
,	O
in	O
response	O
to	O
Malaysia	O
Airlines	O
Flight	O
370	O
,	O
for	O
compliance	O
with	O
the	O
ICAO	B-General_Concept
Global	O
Aeronautical	O
Distress	O
and	O
Safety	O
System	O
(	O
GADSS	O
)	O
requirement	O
for	O
airlines	O
to	O
track	O
their	O
fleets	O
.	O
</s>
<s>
The	O
ICAO	B-General_Concept
describes	O
space-based	O
ADS-B	B-Application
as	O
a	O
technology	O
equalizer	O
,	O
offering	O
developing	O
nations	O
an	O
airspace	B-Application
surveillance	I-Application
capability	O
.	O
</s>
<s>
The	O
FAA	O
plans	O
an	O
evaluation	O
in	O
the	O
Caribbean	O
airspace	O
from	O
March	O
2020	O
until	O
2021	O
,	O
to	O
complement	O
the	O
unreliable	O
Grand	O
Turk	O
Island	O
radar	B-Application
which	O
allow	O
reducing	O
separation	O
from	O
.	O
</s>
