NAVIOR-24S
™
CHAPTER IV
Operation and Performance
67
NAVIOR-24S ™
Revision
V1.00 20.05.2008
System Architecture
The NAVIOR-24S GPS/GLONASS receiver uses 24 processing channels operating on the GPS L1
frequency of 1575.42 MHz and using the coarse acquisition (C/A) code and GLONASS L1
frequency band of 1598,0625…1605,375 MHz and using the coarse CT code . The module uses
custom integrated circuitry designed by NAVIS to track the GPS/GLONASS satellite signals. These
ICs also contain support circuitry to the navigation processor. An ARM microprocessor is used for
tracking, computing a position, and performing the I/O operations.
The NAVIOR-24S GPS/GLONASS receiver receives the amplified GPS/GLONASS satellite
signals feed line connector through the antenna and passes them to the RF down converter. A highly
stable crystal reference oscillator operating at 10.0 MHz is used by the down converter to produce
the signals used by the 24-channel signal processor (ASIC). The 24-channel signal processor tracks
the GPS/GLONASS satellite signals and extracts the carrier code information as well as the
navigation data at 50 bits per second for GPS and 100 bits per second for GLONASS.
Operation of the tracking channels is controlled by the navigation processor. The tracking channels
are used to track the highest up to 24 satellites above the horizon. Then the navigation processor
will use the optimum satellite combination to compute a position. The navigation processor also
manages the ephemeris and almanac data for all of the satellites, and performs the data I/O.
