ComNav G2 - Page 17

ComNav G2 & G2B Installation & Operation Introduction
Document PN 29010093 V1.5 - 15 - 16 December 2016
G2 and G2B they are very similar, except for the Differential GPS (DGPS) correction
features:
• The G2 can obtain DGPS information from many Space-Based Augmentation
System (SBAS) sources (in areas where compatible sources are available &
operational), including WAAS, EGNOS, MSAS, and GAGAN. The G2 can also
accept DGPS information from an external data source.
• The G2B has an additional integrated beacon receiver module, which allows it to
use conventional terrestrial DGPS Radio beacon signals to obtain DGPS
information, in addition to SBAS sources & external DGPS data sources.
The G2 contains a ComNav receiver module (containing two GNSS receivers, a 3-axis
gyro, a 3-axis accelerometer and a 3-axis magnetometer), dual GNSS antennas and a
power supply. The G2B also contains a DGPS Radio beacon receiver module, and an
H-field beacon signals antenna.
When using DGPS corrections (SBAS, external, or Radio beacon), the G2 is capable of
under one metre precision for position sensing. The GPS antennas inside the G2’s
enclosure are separated by approximately 0.5 metres, which provides better than 0.25
degrees of heading sensing precision.
The gyro accelerometer and magnetometer enhance system performance by providing
heading information for up to 1 minute whenever the G2’s normal GPS-based heading is
not available due to signal blockage, or other temporary factors.
The G2 has default settings for easy use in typical marine configurations, as illustrated in
Figure 2 . ComNav’s goal is to be able to use the G2 unit “right out of the box” for most
marine applications, without a need to change system configuration settings.
Information in this manual will guide you in adjusting the G2 unit to operate in the best
possible configuration which suits your needs.
The internal beacon receiver in G2B is configured to operate automatically. However in
certain circumstance a user may want to change its configuration. Refer to Appendix 4 for
instructions of the beacon configuration.