Novatel SUPERSTAR II OM-20000077 - Manual (Page 40)

40 SUPERSTAR II User Manual Rev 3
Chapter 6 Positioning Modes of Operation
maintained close to GPS time to provide a ranging capability.
Figure 7: The SBAS Concept
6.2.1 SBAS Receiver
NovAtel SUPERSTAR II-based receivers are equipped with an SBAS feature. The ability to simultaneously
track two SBAS satellites, and incorporate the SBAS corrections into the position, is available in these models.
These models can output the SBAS data in log format (refer to Message ID# 67, WAAS Data in the L1 GPS
Firmware Reference Manual), and can incorporate these corrections to generate differential-quality position
solutions. Standard SBAS data messages are analyzed based on RTCA standard DO-229B Change 1 Minimum
Operational Performance Standards for GPS/WAAS airborne equipment.
A SBAS-capable receiver will permit anyone within the area of coverage to take advantage of its benefits.
6.2.2 SBAS Messages
The command Message ID# 95, Track SV, enables the use of particular SBAS corrections in the position filter.
Two SBAS-specific messages:
Message ID# 67, SBAS Data
Message ID# 68, SBAS Status
are also available. In order to use these messages, first ensure that your receiver is capable of receiving SBAS
corrections.
StarView allows you to deselect GPS and SBAS system satellites. Select Tool Settings | Deselect | SVs from the
main menu. To track one SBAS satellite in particular, do the following:
1. Select SBAS SVs
2. Select the SBAS satellite that you wish to track by deselecting all the others. This ensures that the
receiver will search for a satellites that is known to be operating and thus a quick acquisition/re-
acquisition of the active SBAS satellite.
3. By default, if you select SBAS SVs alone, the unit is only searching for satellite PRNs 120, 122 and
Reference Station
Master Station
Ground Uplink
Station
Integrity data,
differential corrections,
time control, and status
Geostationary
Satellite (GEO)
GPS User
GPS Satellite
Constellation
Integrity data,
differential corrections,
and ranging control
L1
C-band
L1 & L2
Reference Station Reference Station
L1 & C-band