ZED-F9P - Integration manual
QZSS SLAS is only used if no RTCM correction services are available. If the connection
stream is lost during the operation, the receiver will switch to use the SLAS corrections after
the time set in CFG-NAVSPG-CONSTR_DGNSSTO (60 s by default) has elapsed.
3.3.1 Features
Multiple QZSS SLAS signals can be received simultaneously.
When receiving QZSS SLAS correction data, the ZED-F9P high precision receiver 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 (see ZED-F9P Interface description [
]). The message
UBX-NAV-SLAS provides detailed information about which corrections are available and applied.
Message type
Message content
0
Test mode
47
Monitoring station information
48
PRN mask
49
Data issue number
50
DGPS correction
51
Satellite health
Table 16: Supported QZSS L1S SLAS messages for navigation enhancing
3.3.2 Configuration
To enable support for the necessary QZSS L1S signal, use the CFG-SIGNAL-QZSS_L1S_ENA
configuration item. To configure further QZSS SLAS functionalities, use the CFG-QZSS-USE_SLAS*
configuration items.
Parameter
Description
CFG-QZSS-USE_SLAS_DGNSS
Apply QZSS SLAS corrections
CFG-QZSS-USE_SLAS_TESTMODE
Allow the correction provided by QZSS satellites that are in test mode
CFG-QZSS-
USE_SLAS_RAIM_UNCORR
If this configuration is set, the receiver will try to estimate the position by using only
corrected measurements; if all corrected measurements are not available, it won't
use any corrections. If this configuration is not set, the receiver will mix corrected
and uncorrected measurements for the navigation solution.
Table 17: QZSS SLAS configuration parameters
If the RAIM option is set, other GNSS time systems than the QZSS time system cannot be
observed by measurements.
UBX-18010802 - R08
3 Receiver functionality
Page 29 of 110
Early production information
