NavCom LAND-PAK Rev.N - Manual (Page 51)

Technical Reference Manual Rev. N
Blk = All; Blu = IOP w/Internal Radio ; Red = IOP & LBM ; Grn = Engine only
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0x02 - INITIATE - Initiates a QuickStart based on the latitude, longitude and height input
from the corresponding fields in the x42 message.
On output, the Mode field contains one of the following values::
0x00 - IDLE - Following power-on and prior to any QuickStart having been requested, the
QuickStart mode is reported as ‘Idle’. Once a QuickStart has been initiated, the ‘Idle’ mode
will not be reported again until one of the following occurs:
Power is cycled on the unit.
A QuickStart ‘Idle’ has been requested. If a QuickStart has been initiated and is still in
progress, this will cancel it but not reset RTG navigation. This may result in only partial
completion of the operation. If the reported QuickStart mode indicates successful
completion or proximity failure, this request will return the reported QuickStart mode to
‘Idle’.
A QuickStart ‘reset’ request has been requested. This causes a restart of the entire RTG
navigation mode with no a-priori position information i.e. full pull-in duration.
0x02 - INITIATED - This mode is reported after a QuickStart initiation request has been
received but before the QuickStart operation has actually started. The QuickStart operation
will not begin until RTG navigation commences. This requires at least five satellites each
with full dual frequency tracking and at least 10 seconds of code-carrier smoothing. If, for
example, a QuickStart initiation request is given shortly after power-on, it may be a few
minutes before these conditions are met. During this period, the reported QuickStart mode
would be ‘Initiated’.
0x03 - IN PROGRESS - This mode is reported after a QuickStart has actually commenced
up until the time that either the operation completes or fails or until an ‘Idle’ or ‘Reset’
request are received.
0x04 - COMPLETE - This mode is reported when a QuickStart operation has completed
successfully. It takes 50 seconds from the time the QuickStart first begins (In Progress
reported) until successful completion is reported.
0x05 - FAILED PROXIMITY - While a QuickStart operation is in progress, a check is
performed at each 1Hz navigation epoch which compares the 3D radial distance between
the RTG code solution and the ‘known’ position input with the QuickStart initiation request.
If this distance exceeds 25 meters on the first QuickStart epoch or 15 meters on any of the
subsequent epochs in the 50 second period, the QuickStart is terminated, RTG navigation
is reset (full pull-in required) and the QuickStart mode is reported as ‘Failed Proximity Limit’.
The RTG code solution is the weighted least squares navigation solution performed with
smoothed code (could be single or dual frequency depending on prefilter status) and RTG
clock and orbit corrections. It is independent from the full RTG solution which uses the
phase biases estimated by the RTG extended Kalman filter. It is the latter which is initialized
by a QuickStart operation.