SAM-M10Q - Integration manual
2.1.2.6 Freezing the course over ground
If the low-speed course over ground filter is deactivated or inactive (see section
), the receiver derives the course over ground from the GNSS velocity information.
If the velocity cannot be calculated with sufficient accuracy (for example, with bad signals) or if
the absolute speed value is very low (under 0.1 m/s) then the course over ground value becomes
inaccurate too. In this case the course over ground value is frozen, that is, the previous value is kept
and its accuracy degrades over time. These frozen values will not be output in the NMEA messages
NMEA-RMC and NMEA-VTG unless the NMEA protocol is explicitly configured to do so (see NMEA
protocol configuration in the applicable interface description [
]).
Figure 5: Flowchart of course over ground freezing
2.1.2.7 Super-Signal (Super-S) technology
In normal operating conditions, low signal strength (that is, signal attenuation) indicates possible
degradation due to multi-path. The receiver trusts such signals less in order to preserve the
quality of the position solution in poor signal environments. This feature can result in degraded
performance in situations where the signals are attenuated for another reason, for example due
to antenna placement. In this case, the weak signal compensation feature can be used to restore
normal performance. There are three possible modes:
• Disabled: no weak signal compensation is performed
• Automatic: the receiver automatically estimates and compensates for the weak signal
• Configured: the receiver compensates for the weak signal based on a configured value
These modes can be selected using CFG-NAVSPG-SIGATTCOMP. In the case of the "configured"
mode, the user should input the maximum C/N0 observed in a clear-sky environment, excluding any
outliers or unusually high values. Choose the configured value carefully, as it can have a large impact
on the receiver performance.
UBX-22020019 - R01
2 Receiver functionality
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