MAX-M10M - Integration manual
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Example 1 - SBAS receiver in North America:
In eastern parts of North America, make sure
that EGNOS satellites do not take preference over WAAS satellites. The satellite signals from
the EGNOS system should be disallowed by using the PRN scan mask (configuration key CFG-
SBAS-PRNSCANMASK).
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Example 2 - SBAS receiver in Europe:
Some WAAS satellite signals can be received in western
parts as well as GAGAN SBAS satellites in some parts of Europe, therefore it is recommended
that the satellites from all but the EGNOS system should be disallowed using the PRN scan
mask.
Although u-blox receivers try to select the best available SBAS correction data, it is
recommended to configure them to exclude unwanted SBAS satellites.
To configure the SBAS functionality, use the CFG-SBAS-* configuration group.
Parameter
Description
CFG-SIGNAL-SBAS_ENA
Enabled/disabled status of the SBAS subsystem
CFG-SBAS-USE_TESTMODE
Allow/disallow SBAS usage from satellites in test mode
CFG-SBAS-USE_RANGING
Use the SBAS satellites for navigation (ranging)
CFG-SBAS-USE_DIFFCORR
Combined enable/disable switch for fast, long-term, and ionosphere corrections
CFG-SBAS-USE_INTEGRITY
Apply integrity information data
CFG-SBAS-PRNSCANMASK
Allows selectively enabling/disabling SBAS satellites
Table 11: SBAS configuration parameters
When SBAS integrity data is applied, the navigation engine stops using all signals for which no
integrity data is available (including all non-GPS signals). It is not recommended to enable SBAS
integrity on borders of SBAS service regions in order not to inadvertently restrict the number of
available signals.
SBAS integrity information is required for at least five GPS satellites. If this condition is not met,
SBAS integrity data will not be applied.
When the receiver switches from a solution using correction data to a standard position
solution, the reference frame of the output position will switch from that of the correction data to
that of the standard position solution. For an SBAS solution, this reference frame will be aligned
within a few cm of WGS84 (and modern ITRF realizations).
3.1.2 QZSS SLAS
QZSS SLAS (Sub-meter Level Augmentation Service) is an augmentation technology, which
provides correction data for pseudoranges of GPS, QZSS, and other major GNSS satellites. The
correction stream is transmitted on the L1S signal at the L1 frequency (1575.42 MHz).
For more information on QZSS SLAS, visit
Multiple QZSS SLAS signals can be received simultaneously. When receiving QZSS SLAS correction
data, MAX-M10M will autonomously select the best QZSS satellite. The selection strategy is
determined by the quality of the QZSS L1S signals, the receiver configuration (test mode allowed or
not), and the location of the receiver with respect to the QZSS SLAS coverage area. When outside
of this coverage area, the receiver will likely fall back to using SBAS corrections.
If QZSS SLAS corrections are used in the navigation solution, the differential status will be indicated
in several output messages such as UBX-NAV-PVT, UBX-NAV-STATUS, UBX-NAV-SAT, NMEA-
GGA, NMEA-GLL, NMEA-RMC, and NMEA-GNS. The UBX-NAV-SLAS message provides detailed
information about which corrections are available and applied. Refer to the interface description [
]
for a detailed description of the messages.
UBX-22038241 - R02
3 Receiver functionality
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