RCB-F9T - Integration manual
In order to use time mode, the receiver's position must be known as exactly as possible. Errors in the
fixed position will translate into time errors depending on the satellite constellation.
The following procedures can be used to initialize the timing receiver position:
• Using built-in survey-in procedure to estimate the position.
• Entering coordinates independently generated or taken from an accurate position such as a
survey marker.
3.1.5.4.1 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 Survey-in status can be queried
using the UBX-TIM-SVIN message.
The timing receiver should not be fed RTCM corrections while it is in survey-in mode.
To configure a timing receiver 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. The accuracy of given coordinates in 0.0001
meters (i.e. value 100 equals 1 cm)
Table 4: Configuration items used for setting a timing receiver into Survey-in mode
Set the configuration items shown above into flash memory to perform a survey-in
procedure automatically upon start-up.
3.1.5.4.2 Fixed position
Here the timing receiver position coordinates are entered manually. Any error in the timing receiver
position will directly translate into timing errors.
To configure into Fixed mode (CFG-TMODE-MODE=FIXED), the following items are relevant:
Once the receiver is set in fixed mode, select the position format to use: either LLH or ECEF with
optional high precision (mm) coordinates compared to the standard cm value.
For example, with CFG-TMODE-POS_TYPE=ECEF the timing receiver antenna position can be
entered to cm precision using CFG-TMODE-ECEF_X, CFG-TMODE-ECEF_Y, CFGTMODE-ECEF_Z.
For high precision (mm) coordinates use CFG-TMODEECEF_X_HP, CFG-TMODE-ECEF_Y_HP, CFG-
TMODE-ECEF_Z_HP. The same applies with corresponding coordinates used with CFG-TMODE-
POS_TYPE=LLH.
If the timing receiver is moved during operation then new position coordinates must be
configured.
UBX-19003747 - R04
3 Receiver functionality
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Early production information
