SC872-A
Product User Guide
Product Features
1VV0301202 Rev. 6
Page 17 of 53
2018-12-21
Server-generated AGPS - Extended Prediction Orbit (EPO)
Server-generated ephemeris predictions are maintained on Telit AGPS servers. The predicted
ephemeris file is obtained from the AGPS server and is transmitted to the module over a serial
port. These predictions do not require local broadcast ephemeris collection, and are valid for up
to 14 days.
Note that the EPO data stream does not conform to the NMEA-0183 standard.
Please refer to the Telit EPO Application Note for details.
Example source code is available under NDA.
Contact TELIT for support regarding this service.
Host EPO
The modules can make use of Host-based EPO. If the system design includes a host processor,
it can access server-generated EPO data and send it to the module over a serial port. This data
is valid for six hours.
Host EPO data is not retained over a power cycle.
Note that the EPO data stream does not conform to the NMEA-0183 standard.
Please refer to the MT333x Host EPO Application Note.
Please contact Telit support for further details.
10 Hz Navigation
The default rate of 1 Hz can be changed by command $
PMTK500
to a maximum of 10 Hz.
Enabling the SBAS feature limits the maximum fix rate to 5 Hz.
Elevation Mask Angle
The default elevation mask angle is 5°. It can be changed via the
PMTK311
command.
Static Navigation
Static Navigation is an operating mode in which the receiver will freeze the position fix when the
speed falls below a set threshold (indicating that the receiver is stationary).
The course and altitude are also frozen, and the speed is reported as “0”.
The navigation solution is unfrozen when the speed increases above a threshold or when the
computed position exceeds a set distance (10 m) from the frozen position (indicating that the
receiver is again in motion). The speed threshold can be set via the command.
Set this threshold to zero to disable static navigation.
This feature is useful for applications in which very low dynamics are not expected, the classic
example being an automotive application.
Static Navigation is disabled by default, but can be enabled by command $
PMTK386
.
Jamming Rejection – Active Interference Cancellation (AIC)
The receiver module detects and removes narrow-band interfering signals (jamming signals)
without the need for external components or tuning. It rejects up to 12 CW (Continuous Wave)
type signals of up to –80 dBm (total power signal levels). This feature is useful both in the
design stage and during the production stage for uncovering issues related to unexpected
jamming. When enabled, Jamming Rejection will increase current drain by about 1 mA, and
impact on GNSS performance is low at modest jamming levels. However, at high jamming
