Telit Wireless Solutions SL869T3-I, Руководство пользователя

Страница: 15 / 68

SL869T3-I Product User Guide
1VV0301546 Rev. 3
Page 15 of 68 2021-03-31
Proprietary algorithms within the module perform GPS ephemeris prediction locally from
stored broadcast ephemeris data (which was received from tracked satellites). The
algorithms predict orbital parameters for up to 5 days. The module must operate in Full
Power mode for at least 5 minutes to collect ephemeris data from visible satellites, or 12
hours for the full constellation.
By default, ST-AGPS is disabled.
4.5. RAIM
By default, Receiver Autonomous Integrity Monitoring (RAIM), is enabled. RAIM
functionality can be described as an algorithm that determines the integrity of the GNSS
solution. The RAIM algorithm compares measurements for consistency by means of
“residuals”. A faulty satellite is usually the cause in cases where inconsistency is
detected. If this occurs the receiver will eliminate that satellite from the solution.
4.6. Jamming Mitigation
The Adaptive Notch Filter (ANF) facility reduces the receiver’s susceptibility to jamming
signals. The ANF is enabled for the GPS/GAL/QZSS RF path. The ANF is not available for
the L5 band (NavIC). It can be enabled for the GLONASS/Beidou RF path by command if
either constellation is selected, however it must be disabled when NavIC is selected.
4.7. Position Pinning (Stop Detection)
Position Pinning is an operating mode in which the receiver has detected that no
movement is occurring. The speed will continue to be reported but the course will be
reported as 0.0.
The navigation solution is updated every 40 seconds while the receiver is in the Position
Pinning mode.
This feature is useful for applications in which very low dynamics are not expected, the
classic example being an automotive application.
Position Pinning is enabled by default but can be disabled by command.
4.8. Elevation Mask Angle
The default elevation mask angle is 5°. It can be changed by command to 0
°
to 45
°
.