u-blox ZED-F9P Integration Manual page 19

Configuration item
CFG-TMODE-SVIN_ACC_LIMIT
Table 6: Configuration items used for setting a base station into survey-in
Both requirements (duration time and accuracy limit) must be met before the base station
completes the survey-in process. Once this is done then it will begin to output the base
position message RTCM 1005. The rover will not be able to enter RTK Fixed mode unless it
is receiving RTCM 1005.
There are 3 possible ways to initialize the base station position:
• Use base survey-in to estimate the approximate position.
• Use base fixed position mode where the known accurate position of the base is entered such as
from a survey marker.
• Use rover mode and feed the unit RTCM 3x corrections from a service. Then this estimated RTK
position is used to enter the base into fixed mode with these coordinates.
The base station receiver should not be fed RTCM correction while it is in survey-in mode.
Instead, the base station coordinates should be pre-surveyed using RTCM correction and
then, these coordinates should be used to set the base station in fixed mode.
To set a base station into fixed mode (CFG-TMODE-MODE=FIXED), the relevant configuration items
below need to be set:
Configuration item
CFG-TMODE-MODE
CFG-TMODE-POS_TYPE
CFG-TMODE-ECEF_X
CFG-TMODE-ECEF_Y
CFG-TMODE-ECEF_Z
CFG-TMODE-LAT
CFG-TMODE-LON
CFG-TMODE-HEIGHT
CFG-TMODE-ECEF_X_HP
CFG-TMODE-ECEF_Y_HP
CFG-TMODE-ECEF_Z_HP
CFG-TMODE-LAT_HP
CFG-TMODE-LON_HP
CFG-TMODE-HEIGHT_HP
Table 7: Configuration items used for setting a base station into fixed mode
The high precision option for each of the position types allows you to enter the value in mm
compared to the standard cm value.
Once the receiver is set in Fixed mode, select the position format to use: either LLH or ECEF with
optional high precision (mm) coordinates.
For example, with CFG-TMODE-POS_TYPE=ECEF The base antenna position can be entered to
cm accuracy 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 CFG-TMODE-POS_TYPE=LLH.
UBX-18010802 - R02
Advance Information
Description
Survey-in position accuracy limit
Description
Receiver mode (disabled or survey-in or fixed)
Determines whether the ARP position is given in ECEF or LAT/LON/HEIGHT
ECEF X coordinate of the ARP position
ECEF Y coordinate of the ARP position
ECEF Z coordinate of the ARP position
Latitude of the ARP position
Longitude of the ARP position
Height of the ARP position
High-precision ECEF X coordinate of the ARP position
High-precision ECEF Y coordinate of the ARP position
High-precision ECEF Z coordinate of the ARP position
High-precision latitude of the ARP position
High-precision longitude of the ARP position
High-precision height of the ARP position
3 Getting started
ZED-F9P - Integration Manual
Page 19 of 114