96 MPC User Manual Rev 0D
Appendix C WAAS Overview
Figure 85: The WAAS Concept
C.1 MPC with the WAAS Option
The L1L2W model of the MPC is equipped with the WAAS/EGNOS option. The ability to
simultaneously track two WAAS satellites, and incorporate the WAAS/EGNOS corrections into the
position, is availab le in this model.
This model can output the WAAS data in log format (RAWWAASFRAMEA/B, WAAS0A/B-
WAAS27A/B), and can incorporate these corrections to generate differential-quality position
solutions. Stan dard WAAS/EGNOS da ta messages are analyzed based on RTCA stand ard DO-229B
Change 1 Minimum Operational Performance Standards for GPS/WAAS airborne equipment.
A WAAS/EGNOS-capable MPC will permit anyone within the area of coverage to take advantage of
its benefit s.
C.1.1 WAAS Commands and Logs
The command WAASCORRECTION, enables the use of the WAAS corrections in the position filter.
In order to use this command, first ensure that your receiver is capable of receiving WAAS
corrections.
Several WAAS specific logs also exist and are all prefixed by the word WAAS except for the
RAWWAASFRAME log.
The PSRDIFFSOURCE command sets the station ID value which identifies the reference station from
which to accept psuedorange corrections. All DGPS types may revert to WAAS, if enabled using the
WAASCORRECTION command.
Consult Volume 2 of the OEM4 Users’ Guide for more details on individual WAAS commands and
logs.
Wide-area
Reference Station
(WRS)
Master Station
(WMS)
G
r
o
u
n
d
U
p
l
i
n
k
S
t
a
t
i
o
n
(
G
U
S
)
Wide-area
I
n
t
e
g
r
i
t
y
d
a
t
a
,
d
i
f
f
e
r
e
n
t
i
a
l
c
o
r
r
e
c
t
i
o
n
s
,
t
i
m
e
c
o
n
t
r
o
l
,
a
n
d
s
t
a
t
u
s
G
eostationary
Satellite (GEO)
GPS User
GPS Satellite
Constellation
Integrity da
t
a
,
differential
c
o
r
r
e
c
t
i
o
n
s
,
and ranging
c
o
n
t
r
o
l
L1
C-band
L1 & L2
Reference Station
(WRS)
Wide-area Reference Stati on
(WRS)
Wide-area
L1 & C-band