ashtech DG14, Reference Manual

Page: 87 / 390

Differential Operation 67
Differential Operation
$PASHS,SBA,MAN,xx to enable the Single Manual SBAS mode and use the
SBAS data in the navigation solution.
Dual Manual Mode
In Dual Manual SBAS Mode, the DG16 searches for and tracks the two
specified SBAS satellites (PRN = xx and PRN=yy) on Channel 1 and Channel
2, respectively. Use the
$PASHS,SBA, MAN,xx,yy to enable the Dual
Manual SBAS mode and use the SBAS data in the navigation solution.
DGPS Positioning Using SBAS Corrections
The DG16 can decode, process, and apply SBAS differential corrections
received from the SBAS channels.
Use SBAS message types 6, 8 and 10 to determine and report the quality of
the corrections/solution (e.g. in the GST message). If message type 10 is not
available, then the corresponding error component is set to a NOMINAL
VALUE.
Use the
$PASHS,RTC,SLC,SBA command to enable the SBAS corrected
position with all available SBAS correction components. If you do not want a
differential position output with partial corrections of the SBAS messages, use
the
$PASHS,SBA,PAR,OFF command.
On cold start, the first solution is corrected with all components but the
ionosphere and then the subsequent position fixes are corrected with all
components.
Utilizing SBAS Channel Data
In any of the above SBAS modes of operation, you can select one of three
data utilization options:
1. Use Channel 1 data only: $PASHS,SBA,CDU,CH1
2. Use Channel 1 data when available, and Channel 2 data only as backup:
$PASHS,SBA,CDU,BCP
3. Use data from both Channels simultaneously: $PASHS,SBA,CDU,BTH
Modes 2 and 3 only work in either manual or automatic dual mode of operation.
The default is $PASHS,SBA,CDU,BTH — use data from both Channels
simultaneously.