Inertial Navigation Flashcards
INS do (not) require external input to compute position
not
With ___ from the ADC, they can calculate wind velocity
TAS
INS can work ___ and are (not) undetectable
anyway, they are
They can apply local variation between __N and __S from a table in the database, meaning a flux detector is not required
73 65
If the variation table cannot update the output from true to magnetic, then the set might show either ___ ___ or switch to ___
HDG FAIL TRUE
The difference between WGS84 and the oblique spheroid of the Earth is why ___ ___ is required
Schuler Tuning
Outline the general principle of Inertial Navigation
- Start from a known position
- Calculate present position from directions and speed since then.
The drift should be around _nm per hour for a strapdown system
1
The drift could be _nm per hour for a stable platform
3
The main cause of cumulative distance errors come from wander in the ___ ___ and ___ ___ in the second stage of integration
levelling gyros, integration errors
The accuracy of any computed altitude decreases ___ with time
exponentially
As the accuracy degrades over time, supplementation with ___/___ is required, where it becomes subject to bound errors based on the other system
GPS/navaids
As the system error keeps growing, it is ___, and readings will be inaccurate to some extent
unbounded
The position will be most inaccurate at the top of ___, and just after ___
descent take off
Map shift occurs when the ___
moving map changes position to show the updates
Manual updating of the system is only allowed within __nm of a colocated VOR/DME, or above a visual fix below ___ft
25 5000
Auto updating can take place within __nm of 2 DMEs, or ___nm of a single DME
200 140
GPS is ___ accurate, with low bandwidth
more
Low bandwidth means it has a ___ update rate
slow
IRS and INS are ___ bandwidth systems.
high
There will be ___ INS/IRS systems on modern aircraft
3
The three types of coupling between GPS and INS are:
Uncouple, loosely, tightly
Inertial systems have there own __V DC batteries which run for __ to __ minutes, or they may use a hot bus.
28 20 30
If power is lost, you ___ realign for the rest of the flight
cannot
