ZED-F9P - Integration manual
• If the baseline exceeds 100km, a UBX-INF-WARNING will be output, e.g. "WARNING: DGNSS
long baseline: 102.7 km"
An illustrated procedure for configuring a rover using u-center is shown in the
3.1.5.5 Stationary base operation
The ZED-F9P high precision receiver default operation begins without producing any RTCM
messages. RTCM observation messages will be streamed as soon as they are configured for output.
However, any stationary reference position messages are output only when the base station position
has been initialized and is operating in time mode. Time mode sets the receiver to operate as a
stationary base station in fixed position and only time is estimated.
The following procedures can be used to initialize the base station position:
• Use the built-in survey-in procedure to estimate the position.
• Enter coordinates independently generated or taken from an accurate position such as a survey
marker.
• Use in rover mode and feed the receiver corrections then enter the resultant estimated position
coordinates as above.
3.1.5.5.1 Survey-in
Survey-in is a procedure that is carried out prior to entering time mode. It estimates the receiver
position by building a weighted mean of all valid 3D position solutions.
Two major parameters are required when configuring:
• A
minimum observation time
defines the minimum observation time independent of the
actual number of fixes used for the position estimate. Values can range from one day for high
accuracy requirements to a few minutes for coarse position determination.
• A
3D position standard deviation
defines a limit on the spread of positions that contribute to
the calculated mean.
Survey-in ends when both requirements are successfully met. The receiver begins operation in time
mode and can output a base position message if configured. The survey-in status can be queried
using the UBX-NAV-SVIN message.
The base station receiver should not be fed RTCM corrections while it is in survey-in mode.
If a corrected position is desired, the base station coordinates should be pre-surveyed using
RTCM corrections; the resultant position can be used to set the base station in fixed mode.
To configure a base station into survey-in mode (CFG-TMODE-MODE=SURVEY_IN), the following
items are required:
Configuration item
Description
CFG-TMODE-MODE
Receiver mode (disabled, survey-in or fixed)
CFG-TMODE-SVIN_MIN_DUR
Survey-in minimum duration
CFG-TMODE-SVIN_ACC_LIMIT
Survey-in position accuracy limit
Table 8: Configuration items used for setting a base station into survey-in mode
3.1.5.5.2 Fixed position
Here the receiver position coordinates are entered manually. Any error in the base station position
will directly translate into rover position errors. The base station position accuracy should therefore
match or exceed the desired rover absolute position accuracy.
To configure Fixed mode (CFG-TMODE-MODE=FIXED), the following items are relevant:
UBX-18010802 - R08
3 Receiver functionality
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Early production information
