<s>
An	O
enhanced	B-Device
flight	I-Device
vision	I-Device
system	I-Device
(	O
EFVS	B-Device
,	O
sometimes	O
EVS	O
)	O
is	O
an	O
airborne	O
system	O
which	O
provides	O
an	O
image	O
of	O
the	O
scene	O
and	O
displays	O
it	O
to	O
the	O
pilot	O
,	O
in	O
order	O
to	O
provide	O
an	O
image	O
in	O
which	O
the	O
scene	O
and	O
objects	O
in	O
it	O
can	O
be	O
better	O
detected	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
an	O
EFVS	B-Device
is	O
a	O
system	O
which	O
provides	O
the	O
pilot	O
with	O
an	O
image	O
which	O
is	O
better	O
than	O
unaided	O
human	O
vision	O
.	O
</s>
<s>
An	O
EFVS	B-Device
includes	O
imaging	O
sensors	O
(	O
one	O
or	O
many	O
)	O
such	O
as	O
a	O
color	O
camera	O
,	O
infrared	O
camera	O
or	O
radar	B-Application
,	O
and	O
typically	O
a	O
display	O
for	O
the	O
pilot	O
,	O
which	O
can	O
be	O
a	O
head-mounted	B-General_Concept
display	I-General_Concept
or	O
head-up	B-Application
display	I-Application
.	O
</s>
<s>
An	O
EFVS	B-Device
may	O
be	O
combined	O
with	O
a	O
synthetic	B-General_Concept
vision	I-General_Concept
system	I-General_Concept
to	O
create	O
a	O
combined	O
vision	O
system	O
.	O
</s>
<s>
An	O
EFVS	B-Device
can	O
be	O
mounted	O
on	O
military	O
or	O
civilian	O
aircraft	O
,	O
fixed	O
wing	O
(	O
airplane	O
)	O
or	O
rotary	O
wing	O
(	O
helicopter	O
)	O
.	O
</s>
<s>
Enhanced	O
vision	O
is	O
a	O
related	O
to	O
Synthetic	B-General_Concept
vision	I-General_Concept
system	I-General_Concept
which	O
incorporates	O
information	O
from	O
aircraft	O
based	O
sensors	O
(	O
e.g.	O
,	O
near-infrared	O
cameras	O
,	O
millimeter	O
wave	O
radar	B-Application
)	O
to	O
provide	O
vision	O
in	O
limited	O
visibility	O
environments	O
.	O
</s>
<s>
The	O
first	O
civil	O
certification	O
of	O
an	O
enhanced	B-Device
vision	I-Device
system	I-Device
on	O
an	O
aircraft	O
was	O
pioneered	O
by	O
Gulfstream	O
Aerospace	O
using	O
a	O
Kollsman	O
IR	O
camera	O
.	O
</s>
<s>
The	O
Gulfstream	O
EVS	O
and	O
later	O
EVS	O
II	O
systems	O
use	O
an	O
IR	O
camera	O
mounted	O
in	O
the	O
aircraft	O
's	O
nose	O
to	O
project	O
a	O
raster	O
image	O
on	O
the	O
head-up	B-Application
display	I-Application
(	O
HUD	B-Application
)	O
.	O
</s>
<s>
The	O
IR	O
image	O
on	O
the	O
HUD	B-Application
is	O
conformal	O
to	O
the	O
outside	O
scene	O
,	O
meaning	O
that	O
objects	O
detected	O
by	O
the	O
IR	O
camera	O
are	O
the	O
same	O
size	O
and	O
aligned	O
with	O
objects	O
outside	O
the	O
aircraft	O
.	O
</s>
<s>
The	O
FAA	O
grants	O
some	O
additional	O
operating	O
minimums	O
to	O
aircraft	O
equipped	O
with	O
certified	O
enhanced	B-Device
vision	I-Device
systems	I-Device
allowing	O
Category	O
I	O
approaches	O
to	O
Category	O
II	O
minimums	O
.	O
</s>
<s>
Other	O
sensor	O
types	O
have	O
been	O
flown	O
for	O
research	O
purposes	O
,	O
including	O
active	O
and	O
passive	O
millimeter	O
wave	O
radar	B-Application
.	O
</s>
<s>
In	O
2009	O
,	O
DARPA	O
provided	O
funding	O
to	O
develop	O
"	O
Sandblaster	O
"	O
,	O
a	O
millimeter	O
wave	O
radar	B-Application
based	O
enhanced	B-Device
vision	I-Device
system	I-Device
installed	O
on	O
helicopters	O
which	O
enables	O
the	O
pilot	O
to	O
see	O
and	O
avoid	O
obstacles	O
in	O
the	O
landing	O
area	O
that	O
may	O
be	O
obscured	O
by	O
smoke	O
,	O
sand	O
,	O
or	O
dust	O
.	O
</s>
<s>
The	O
combination	O
of	O
dissimilar	O
sensor	O
types	O
such	O
as	O
long	O
wave	O
IR	O
,	O
short	O
wave	O
IR	O
,	O
and	O
millimeter	O
wave	O
radar	B-Application
can	O
help	O
ensure	O
that	O
real	O
time	O
video	O
imagery	O
of	O
the	O
outside	O
scene	O
can	O
be	O
provided	O
to	O
the	O
pilot	O
in	O
all	O
types	O
of	O
visibility	O
conditions	O
.	O
</s>
<s>
For	O
example	O
,	O
long	O
wave	O
IR	O
sensor	O
performance	O
can	O
be	O
degraded	O
in	O
some	O
types	O
of	O
large	O
water	O
droplet	O
precipitation	O
where	O
millimeter	O
wave	O
radar	B-Application
would	O
be	O
less	O
affected	O
.	O
</s>
<s>
It	O
was	O
not	O
clear	O
at	O
the	O
time	O
whether	O
an	O
EFVS	B-Device
could	O
be	O
used	O
for	O
descending	O
below	O
that	O
height	O
.	O
</s>
<s>
This	O
marks	O
the	O
first	O
time	O
an	O
EFVS	B-Device
gave	O
a	O
concrete	O
commercial	O
advantage	O
over	O
unaided	O
vision	O
.	O
</s>
<s>
The	O
first	O
EVS	O
's	O
comprised	O
a	O
cooled	O
mid-wave	O
(	O
MWIR	O
)	O
Forward	O
looking	O
infrared	O
(	O
FLIR	O
)	O
camera	O
,	O
and	O
a	O
HUD	B-Application
,	O
certified	O
for	O
flight	O
with	O
the	O
Gulfstream	O
V	O
aircraft	O
.	O
</s>
<s>
An	O
EFVS	B-Device
can	O
be	O
mounted	O
on	O
any	O
type	O
of	O
craft	O
.	O
</s>
<s>
The	O
typical	O
platform	O
is	O
a	O
small	O
passenger	O
plane	O
,	O
since	O
it	O
is	O
more	O
cost-effective	O
to	O
use	O
an	O
EFVS	B-Device
than	O
an	O
instrumental	O
landing	O
system	O
,	O
which	O
is	O
used	O
in	O
larger	O
passenger	O
airplanes	O
.	O
</s>
<s>
NASA	O
is	O
considering	O
using	O
an	O
EFVS	B-Device
to	O
enable	O
pilot	O
vision	O
on	O
this	O
plane	O
.	O
</s>
<s>
The	O
sensor	O
unit	O
of	O
the	O
EFVS	B-Device
can	O
include	O
a	O
single	O
imaging	O
sensor	O
,	O
multiple	O
cameras	O
and	O
also	O
additional	O
navigation-aiding	O
sensors	O
.	O
</s>
<s>
Such	O
a	O
camera	O
can	O
be	O
a	O
high	O
dynamic	O
range	O
camera	O
for	O
day	O
vision	O
,	O
a	O
low-light	O
CMOS	B-Architecture
camera	I-Architecture
(	O
sometimes	O
called	O
scientific	O
CMOS	O
or	O
sCMOS	O
)	O
and	O
night	O
vision	O
goggles	O
.	O
</s>
<s>
It	O
can	O
offer	O
advantages	O
for	O
an	O
EFVS	B-Device
,	O
such	O
as	O
:	O
better	O
haze	O
penetration	O
than	O
VIS	O
,	O
natural	O
scene	O
contrast	O
similar	O
to	O
VIS	O
unlike	O
a	O
MWIR	O
or	O
LWIR	O
.	O
</s>
<s>
SWIR	O
cameras	O
are	O
available	O
commercially	O
,	O
but	O
there	O
is	O
no	O
reported	O
use	O
of	O
a	O
SWIR	O
camera	O
in	O
a	O
commercial	O
EFVS	B-Device
.	O
</s>
<s>
Use	O
of	O
passive	O
millimeter	O
wave	O
cameras	O
are	O
a	O
promising	O
technology	O
for	O
aircraft	O
based	O
Enhanced	B-Device
Flight	I-Device
Vision	I-Device
Systems	I-Device
as	O
well	O
as	O
ship	O
navigation	O
in	O
low	O
visibility	O
,	O
and	O
industrial	O
applications	O
.	O
</s>
<s>
An	O
imaging	O
radar	B-Application
has	O
also	O
been	O
proposed	O
by	O
NASA	O
in	O
the	O
1990s	O
.	O
</s>
<s>
An	O
imaging	O
radar	B-Application
requires	O
very	O
high	O
resources	O
for	O
computation	O
,	O
since	O
the	O
image	O
is	O
formed	O
by	O
digital	O
calculation	O
and	O
not	O
by	O
a	O
lens	O
.	O
</s>
<s>
Image	B-Algorithm
registration	I-Algorithm
is	O
the	O
comparison	O
of	O
the	O
image	O
acquired	O
from	O
an	O
imaging	O
sensor	O
to	O
a	O
recorded	O
image	O
(	O
usually	O
from	O
satellite	O
)	O
which	O
has	O
a	O
known	O
global	O
position	O
.	O
</s>
<s>
An	O
inertial	O
navigation	O
system	O
(	O
INS	O
)	O
or	O
inertial	O
measurement	O
unit	O
(	O
IMU	O
)	O
is	O
a	O
device	O
which	O
measures	O
acceleration	O
,	O
angular	O
velocity	O
,	O
and	O
sometimes	O
the	O
magnetic	O
field	O
,	O
using	O
a	O
combination	O
of	O
accelerometers	O
and	O
gyroscopes	B-Application
,	O
sometimes	O
also	O
magnetometers	O
.	O
</s>
<s>
Combined	O
with	O
a	O
GPS	O
or	O
image	B-Algorithm
registration	I-Algorithm
,	O
it	O
can	O
provide	O
an	O
accurate	O
absolute	O
position	O
.	O
</s>
<s>
A	O
radar	B-Application
altimeter	O
can	O
provide	O
the	O
aircraft	O
elevation	O
above	O
the	O
terrain	O
with	O
high	O
precision	O
and	O
fidelity	O
.	O
</s>
<s>
The	O
display	O
to	O
the	O
pilot	O
is	O
a	O
see-through	B-Device
display	I-Device
,	O
which	O
means	O
it	O
allows	O
both	O
seeing	O
the	O
scene	O
directly	O
with	O
unaided	O
vision	O
and	O
seeing	O
a	O
projected	O
image	O
.	O
</s>
<s>
Head-mounted	B-General_Concept
display	I-General_Concept
or	O
helmet-mounted	B-Application
display	I-Application
.	O
</s>
<s>
Head-up	B-Application
display	I-Application
is	O
a	O
system	O
composed	O
of	O
a	O
large	O
reflecting	O
plate	O
(	O
called	O
combiner	O
)	O
positioned	O
in	O
front	O
of	O
the	O
pilot	O
,	O
and	O
a	O
projection	O
system	O
.	O
</s>
<s>
A	O
head-down	B-Application
display	I-Application
is	O
an	O
LCD	O
screen	O
installed	O
below	O
the	O
window	O
,	O
hence	O
the	O
name	O
"	O
head-down	O
"	O
.	O
</s>
<s>
It	O
is	O
generally	O
not	O
used	O
as	O
an	O
EFVS	B-Device
display	O
,	O
since	O
the	O
external	O
scene	O
cannot	O
be	O
seen	O
when	O
looking	O
at	O
it	O
.	O
</s>
<s>
The	O
displayed	O
EFVS	B-Device
imagery	O
and	O
symbology	O
must	O
be	O
presented	O
so	O
that	O
they	O
are	O
aligned	O
with	O
and	O
scaled	O
to	O
the	O
external	O
view	O
.	O
</s>
<s>
A	O
head-up	B-Application
display	I-Application
must	O
be	O
harmonized	O
with	O
the	O
imaging	O
sensors	O
.	O
</s>
<s>
A	O
head-mounted	B-General_Concept
display	I-General_Concept
moves	O
constantly	O
with	O
the	O
pilot	O
's	O
head	O
,	O
and	O
must	O
therefore	O
be	O
tracked	O
continuously	O
so	O
that	O
the	O
image	O
displayed	O
conforms	O
to	O
the	O
scene	O
in	O
real-time	O
,	O
see	O
Helmet-mounted	B-Application
display	I-Application
.	O
</s>
<s>
An	O
EVS	O
is	O
certified	O
for	O
landing	O
by	O
the	O
FAA	O
only	O
if	O
it	O
is	O
combined	O
with	O
a	O
HUD	B-Application
,	O
in	O
which	O
case	O
it	O
is	O
called	O
an	O
EFVS	B-Device
.	O
</s>
<s>
This	O
switching	O
can	O
be	O
avoided	O
if	O
a	O
see-through	B-Device
display	I-Device
is	O
installed	O
to	O
display	O
information	O
to	O
the	O
pilot	O
while	O
also	O
looking	O
out	O
.	O
</s>
<s>
HUDs	B-Application
then	O
EVS	O
came	O
to	O
business	O
jets	O
in	O
2001	O
and	O
the	O
FAA	O
published	O
EVFS	O
rules	O
in	O
2016	O
to	O
land	O
in	O
poor	O
visibility	O
through	O
a	O
HUD	B-Application
,	O
precluding	O
PFD	O
use	O
,	O
with	O
combined	O
enhanced	O
and	O
synthetic	B-General_Concept
vision	I-General_Concept
system	I-General_Concept
(	O
CVS	O
)	O
.	O
</s>
<s>
Under	O
current	O
FAR	O
91.175	O
regulations	O
,	O
airplanes	O
with	O
HUDs	B-Application
can	O
attain	O
before	O
switching	O
to	O
natural	O
vision	O
to	O
land	O
,	O
permitting	O
all-weather	O
landing	O
in	O
airports	O
without	O
ILS	O
Cat	O
II/III	O
approaches	O
.	O
</s>
<s>
After	O
beginning	O
work	O
in	O
2011	O
,	O
Dassault	O
was	O
first	O
to	O
certify	O
its	O
CVS	O
with	O
its	O
Elbit	O
HUD	B-Application
and	O
camera	O
,	O
FalconEye	O
,	O
in	O
October	O
2016	O
in	O
the	O
Falcon	O
2000	O
and	O
900	O
,	O
then	O
in	O
the	O
8X	O
in	O
early	O
2017	O
.	O
</s>
<s>
In	O
July	O
2018	O
,	O
FAA	O
certification	O
of	O
the	O
Gulfstream	O
G500	O
allowed	O
the	O
EFVS	B-Device
to	O
provide	O
the	O
only	O
visual	O
cues	O
for	O
landing	O
down	O
to	O
runway	O
visual	O
range	O
,	O
to	O
touchdown	O
and	O
rollout	O
,	O
after	O
50	O
test	O
approaches	O
,	O
and	O
testing	O
to	O
lower	O
visibilities	O
could	O
allow	O
dropping	O
the	O
limit	O
,	O
with	O
approvals	O
for	O
previous	O
Gulfstreams	O
to	O
follow	O
.	O
</s>
<s>
By	O
October	O
2018	O
,	O
the	O
Falcon	O
8X	O
FalconEye	O
was	O
approved	O
by	O
the	O
FAA	O
and	O
EASA	B-Device
for	O
approaches	O
down	O
to	O
.	O
</s>
<s>
A	O
dual	O
HUD	B-Application
FalconEye	O
will	O
allow	O
EVS-to-land	O
in	O
2020	O
,	O
without	O
using	O
natural	O
vision	O
.	O
</s>
<s>
Bombardier	O
Globals	O
use	O
a	O
Rockwell	O
Collins	O
HUD	B-Application
and	O
camera	O
while	O
Gulfstreams	O
have	O
a	O
cooled	O
Kollsman	O
(	O
Elbit	O
)	O
camera	O
and	O
a	O
Rockwell	O
Collins	O
HUD	B-Application
.	O
</s>
