ZED-F9K - Integration manual
3.2.7.1 Introduction
ZED-F9K provides a low-latency position, velocity, and vehicle attitude solution to be output at
a high rate by utilizing sensor-based propagation in between GNSS-measurement updates, thus
prioritizing the time-critical data.
The receiver issues priority navigation messages first, and non-priority navigation messages when
time allows it. The non-priority messages might, therefore, be output with some delay.
The following tables list priority navigation messages.
UBX protocol message
Content
Priority
level
Output rate
UBX-NAV-PVT
Position, velocity, attitude and time data
High
0-30 Hz (Configurable)
UBX-NAV-HPPOSECEF
High-precision position solution in ECEF
High
0-30 Hz (Configurable)
UBX-NAV-POSECEF
Position solution in ECEF
High
0-30 Hz (Configurable)
UBX-NAV-HPPOSLLH
High-precision geodetic position solution
High
0-30 Hz (Configurable)
UBX-NAV-POSLLH
Geodetic position solution
High
0-30 Hz (Configurable)
UBX-NAV-ATT
Attitude data
High
0-30 Hz (Configurable)
UBX-ESF-INS
INS data
High
0-30 Hz (Configurable)
UBX-NAV-VELECEF
ECEF velocities
High
0-30 Hz (Configurable)
UBX-NAV-VELNED
NED velocities
High
0-30 Hz (Configurable)
Table 12: UBX priority navigation messages
NMEA protocol message
Content
Priority
level
Output rate
NMEA-Standard-DTM
Datum info
High
0-30 Hz (Configurable)
NMEA-Standard-RMC
Recommended minimum data
High
0-30 Hz (Configurable)
NMEA-Standard-VTG
Course over ground and ground speed
High
0-30 Hz (Configurable)
NMEA-Standard-GNS
GNSS fix data
High
0-30 Hz (Configurable)
NMEA-Standard-GGA
Global positioning system fix data
High
0-30 Hz (Configurable)
NMEA-Standard-GLL
Latitude and longitude, with time of position
fix and status
High
0-30 Hz (Configurable)
NMEA-Standard-THS
True heading and status
High
0-30 Hz (Configurable)
NMEA-PUBX-POSITION
Latitude and longitude position data
High
0-30 Hz (Configurable)
Table 13: NMEA priority navigation messages
The ZED-F9K requires an initialization phase if the sensors have not been calibrated. During
this initialization, the receiver delivers GNSS-only navigation solution data, still ensuring
high-rate and low-latency output. The ZED-F9K works optimally in priority navigation mode
when the IMU and WT sensors have been calibrated, and the alignment angles are correct.
If priority navigation mode is enabled, comparing time information of a non-priority UBX
message with a priority NMEA message may not be sensible (see the
section). Thus, it is recommended to compare messages with the same priority level. For
instance, comparing the time information of a non-priority UBX message with a non-priority
NMEA message (such as NMEA-Standard-ZDA).
When switching back from priority mode to non-priority mode, the TOW could jump back in
time, similarly, switching from non-priority to priority mode may cause TOW to jump ahead
in time.
UBX-20046189 - R01
3 Receiver functionality
Page 32 of 105
C1-Public
Early production information
