Identify the Principles of Inertial Navigation System Flashcards
By calculating the range of _____ satellites, an exact 3-D position is calculated.
Four
Inertial sensors consist of _____ and _____ oriented in three axes, pitch, roll and yaw which measure changes in speed, attitude, and heading.
Gyroscopes, Accelerometers
When an INS equipped vehicle stops moving, the INU calibrates itself by measuring gravity, the rotation of the Earth, and by seeking True North. This process is called a _____.
ZUPT
The _____ uses tracking information to calculate precise satellite position and satellite clock error for each individual satellite.
Control Center
The Global Positioning System space segment is arranged in _____ rings that orbit the Earth twice a day.
6
INS accuracy tends to degrade in direct proportion to time and _____.
Distance Traveled
The _____ sends data to the TAB/TOW elevation drive and commands the TAB/TOW to stow if vehicle speed exceeds 3 miles per hour.
Vehicle Motion Sensor (VMS)
INU measurement error that accumulates over time making position estimations less accurate is called _____.
Drift
_____ determines the amount of Earth rotational rate that we can use for gyro-compassing.
Latitude
Laser gyroscopes provide the same information as mechanical gyroscopes and have the added benefit of _____.
No moving parts
Typical alignment times for INU systems are between _____ and _____ minutes.
5-18
The _____ is a stronger, encrypted, military specific GPS signal designed to meet military positioning, navigation, and timing (PNT) needs.
GPS M-CODES
During INS alignment, the system must mathematically level the accelerometers with the _____ and determine _____.
Horizon, True North
The _____ is updated every 12.5 minutes and once updated the display changes to 1 day.
Almanac Age
At latitudes greater than _____ North or South, the amount of Earth rate is so small that it is swamped by the error tolerance of the accelerometers and alignment is not possible.
70°
_____ are unmanned stations located throughout the world that use special GPS receivers to track each satellite.
Monitor Stations
A _____ must be conducted when the vehicle latitude is greater than 49° but less than 70° (North or South) and turret power has been cycled.
Dynamic Alignment
A constellation of _____ satellites transmit radio frequency signals for use by end user navigation sets.
24
The _____ optimizes performance of the INS by allowing multi-sensor observation of the Earth’s rotation.
Dynamic Alignment
The Global Positioning System ground control segment consists of _____ and a _____ that tracks satellites, checks, and controls orbits, and updates the satellite navigation data message.
Monitor Stations, Control Center
