your position is our focus
4 Navigation
Once
the
GPS
receiver
is
tracking
enough
satellites,
it
uses
the
measurements
to
calculate
the
current
position.
This
part
of
the
code
is
called
Navigation
Solution.
The
following
section
discusses
mainly
the
usage
of
the
UBX
proprietary
messages
UBX
–
CFG
(Config)
–
RATE
(Rates),
UBX
–
CFG
(Config)
–
DAT
(Datums)
and
UBX
–
CFG
(Config)
–
NAV2
(Navigation2)
to
configure
the
Navigation
Engine
of
the
ANTARIS
®
4
GPS
receiver.
To
get
an
optimal
setting
the
application
environment
must
be
considered.
4.1.1 Overview
Parameter
Description
Navigation Output
The
ANTARIS
®
4
GPS
Technology
outputs
the
navigation
data
in
LLA
(Latitude,
Longitude
and
Altitude),
ECEF
coordinate
frame
or
Universal
Transverse
Mercator
(UTM)
format.
The
LLA
output
can
be
configured
to
one
out
of
more
than
200
pre-defined
datums,
or
to
a
user
datum.
Map Datum
The
ANTARIS
®
4
GPS
Technology
supports
more
than
200
different
map
datums
(including
one
user
specific
datum)
and
Universal
Transverse
Locator
(UTM)
Navigation Update Rate
The
ANTARIS
®
4
GPS
Technology
supports
navigation
update
rates
higher
than
1
update
per
second.
For
LEA-4R/TIM-4R
the
Navigation
Update
Rate
is
fixed
at
1Hz.
Dynamic Platform Model
Dynamic
models
adjust
the
navigation
engine,
tuning
the
GPS
performance
to
the
application
environment.
Do
not
change
for
LEA-4R/TIM-4R
Allow Almanac Navigation
Enable
Almanac
Navigation
(without
ephemeris
data)
as
a
degraded
mode
to
realize
fast
fixes
with
reduced
position
accuracy.
Navigation Input Filters
Applies
a
mask
to
the
input
parameters
of
the
navigation
engine
to
filter
the
input
data.
It
screens
potentially
poor
quality
data
preventing
its
use
in
the
navigation
engine.
Navigation Output Filters
Applies
a
mask
to
the
position
fixes
to
prevent
poor
quality
from
being
output.
Internally,
the
positions
are
still
calculated
to
further
track
the
SVs.
RAIM
Receiver
Autonomous
Integrity
Monitoring
DGPS
Specific
Differential
GPS
parameters
Table 9: Overview GPS Navigation Parameter
4.1.1.1 Navigation
Output
The
ANTARIS
®
4
GPS
Technology
outputs
the
navigation
data
in
LLA
(Latitude,
Longitude
and
Altitude),
ECEF
(Earth
Centered
Earth
Fixed)
or
UTM
(Universal
Transverse
Mercator)
format.
The
LLA
output
can
be
configured
to
one
out
of
more
than
200
predefined
datums
or
to
a
user
datum.
The
default
datum
is
WGS84.
The
altitude
is
available
as
height
above
ellipsoid
(HAE).
The
height
above
mean
sea
level
(MSL)
is
available
if
the
default
datum
WGS84
is
selected.
!
Note
Refer
to
the
ANTARIS
®
4
System
Integration
Manual
[5]
for
a
list
of
all
predefined
datums.
4.1.2 Navigation Update Rate
The
LEA-4R/TIM-4R
supports
only
an
update
rate
of
1
Hz.
LEA-4R
/
TIM-4R
-
System
Integration
Manual
/
Reference
Design
Navigation
GPS.G4-MS4-05043
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