Navigation Flashcards
LWINS
Light Weight Inertial Navigation System - Total of 3 navigation sets with interface to the GPS to provide navigation data to MCs and attitude data to FCCs
MAGR
Miniature Airborne GPS Receiver - Uses satellite and internal computers to provide date, time, lat/long, altitude, velocity to INS and MCs
Kalman Filter
Mathematical program that blends GPS data with INS data to provide accurate position
TACAN Range
Up to 390 nm
PARTIAL NAV READY advisory
A single INS has completed full alignment
NAV READY advisory
All 3 INSs have completed alignment
Figure of Merit (FOM)
Displayed in the upper left corner of the PFD, VSD, and Hover Display. It represents the quality of the position data used for navigation. The Lower the number the more accurate the position.
FOM 1
Less than 26 meters position error
FOM 2
26-50 meter position error
FOM 3
51-75 meter position error
FOM 4
76-100 meter position error
FOM 5
101-200 meter position error
FOM 6
201-500 meter position error
FOM 7
501-1,000 meter position error
FOM 8
1,001-5,000 meter position error
FOM 9
Greater than 5,000 meter position error
DEGRADED NAV READY advisory
At least one LWINS is in degraded NAV mode meaning that less than full navigation mode but better than attitude mode.
POSITION DISAGREE Advisory
There is a difference in position of more than 250 meters between any of the LWINS
GPS MONITOR FAULT Advisory
GPS horizontal or vertical limit has been exceeded or it is unusable to detect and report an exceedence due to less than 5 satellite vehicles
GPS PERFORMANCE DEGR Advisory
GPS solution is degraded due to poor satellite signal quality or it is not in sync with LWINS