SL876Q5-A
Product User Guide
1VV0301333 Rev. 2
Page 19 of 68
2017-06-27
4. PRODUCT FEATURES
Built-in Antenna and Switch
The module includes a built-in tri-band chip antenna and an RF switch that provides for input
from an external active antenna.
Multi-Constellation Navigation
GPS and GLONASS constellations are enabled by default.
The user may enable or disable GPS, GLONASS, and/or BDS constellations via OSP
command MID 222,16. Use of GLONASS or BDS alone may not give optimum positioning
results depending on the region that the receiver is located in.
Quasi-Zenith Satellite System (QZSS) support
The Japanese SBAS satellites are in a highly-inclined elliptical orbit which is geosynchronous
(not geostationary) and has analemma-like ground tracks. This orbit allows continuous
coverage over Japan using only three satellites. Their primary purpose is to provide
augmentation to the GPS system, but the signals may also be used for ranging.
QZSS ranging is disabled by default, but can be enabled via
OSP MID 222,16
command.
Satellite Based Augmentation System (SBAS)
The receiver is capable of using SBAS satellites both as a source of differential corrections
and satellite ranging measurements. These systems (WAAS, EGNOS, GAGAN and MSAS)
use geostationary satellites to transmit regional corrections via a GNSS-compatible signal.
SBAS Corrections
The SBAS satellites transmit a set of differential corrections to their respective regions. The
use of SBAS corrections can improve positioning accuracy.
SBAS corrections for GPS are disabled by default but can be enabled via
OSP MIDs 133, 138,
and 170
commands. Thereafter, the receiver will demodulate and use corrections data from
the SBAS signal.
SBAS Ranging
The use of SBAS satellites can augment the number of measurements available for the
navigation solution, thus improving availability and accuracy.
SBAS satellite ranging is disabled by default but can be enabled via a $PSRF103 MNEA
command or OSP Mode Control command
(MID 136
).
Assisted GPS (AGPS) - SiRFInstantFix™
A GNSS receiver requires ephemeris data to calculate the precise position in space of each
satellite to be used in the navigation solution. Since the satellites move at a speed of 3874
km/s along their orbits and are subject to gravitational perturbations from all masses in the
solar system, this data must be both current and accurate. Each GPS satellite transmits a
complete set of its ephemeris coefficients (called the broadcast ephemeris or BE) every 30
seconds. This is therefore the minimum time required for a cold start Time to First Fix (TTFF).
The BE data is usually refreshed every 2 hours.
Summary of Contents for SL876Q5-A
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