Jackson Labs Micro-JLT GNSS, User Manual

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Micro-JLT GNSS™ User Manual
26 © 2019 Jackson Labs Technologies, Inc.
The Hold position can be set manually by the user or can be the result of a position Auto Survey
executed by the GNSS receiver.
If the Timing Mode is set to RSTSURV, the GNSS receiver will start an Auto Survey every time the
unit is powered-on and following the Survey sequence, the GNSS receiver will run with the timing
features enabled. Once in Position Hold mode, the antenna location should be held completely
stationary.
3.3.26 GPS:SURVey ONCE
This command starts a Survey. At the end of the Survey, the calculated Hold position will be stored
in NVRAM. The Survey parameters can be set with the
GPS:SURVey:DURation <sec> and
GPS:SURVey:VARIANCE <mm^2> commands.
The GNSS receiver will stop the Survey when the minimal duration has been reached and the
variance of the average position is under the specified minimum variance.
3.3.27 GPS:SURVey:DURation <sec>
This command sets the Survey minimal duration. This minimum value is used as a threshold under
which the GNSS receiver can stop the Survey.
The GNSS receiver will stop the Survey when the minimal duration has been reached and the
variance of the average position is under the specified minimum variance.
3.3.28 GPS:SURVey:VARIANCE <mm^2>
This command specifies the minimum variance of the average position computed during the Survey.
This minimum value is used as a threshold under which the GNSS receiver can stop the Survey.
The GNSS receiver will stop the Survey when the minimal duration has been reached and the
variance of the average position is under the specified minimum variance.
3.3.29 GPS:HOLD:POSition <cm, cm, cm>
This command allows the user to specify manually the exact position of the unit. This command will
overwrite the Hold position in NVRAM. Subsequent Survey also will overwrite the Hold position.
The Hold position is stored in ECEF coordinates.
3.3.30 GPS:SURVEY:STATUS?
This query displays the current status of the survey. The status of the survey is in one of the 3 states:
ACTIVE : a survey is in progress
VALID : a survey has been achieved successfully and the GNSS receiver is now using this Hold
position as reference.
INVALID : no survey are in progress or have been achieved since the last power cycle.
When in ACTIVE or VALID state, this query will also display the duration, the Hold position in
ECEF coordinates and the position variance .