An inertial frame of reference in classical physics and special relativity possesses the property that in this frame of reference a body with zero net force acting upon it does not accelerate; that is, such a body is at rest or moving at a constant velocity.
In strapdown inertial systems, accelerometers and (laser/optical) rate gyros are aligned in the aircraft reference system, and measurements are done related to this system. The system will still be able to provide aircraft attitude.

Figure 1: The body and global frames of reference. However, there are many complications that make alignment both time consuming and complex. Older inertial systems can be partially realigned in flight if the reference is lost (the position is lost).

The keyboard is used to initialize the system.

The inertial reference system (IRS) includes two inertial reference units (IRU), one inertial system display unit (ISDU), one mode select unit (MSU), one master caution unit (MCU), two digital/analog adapters (DAA) and two radio digital distance magnetic indicators (RDDMI).
A latitude/longitude coordinate system is used when giving the location output.

The basic concept of aligning an inertial navigation system is quite simple and straight forward.

But the north direction and the current position will be lost. The two IRS switches in the normal (navigation) position. An interface panel for three air data and inertial reference systems on an Airbus. The basic concept of aligning an inertial navigation system is quite simple and straight forward. A latitude/longitude coordinate system is used when giving the location output. The basic concept of aligning an inertial navigation system is quite simple and straight forward. 4. However, there are many complications that make alignment both time consuming and complex. An interface panel for three air data and inertial reference systems on an Airbus.

Latitude and longitude position is displayed at the top. However, there are many complications that make alignment both time consuming and complex. However, there are many complications that make alignment both time consuming and complex.

The basic concept of aligning an inertial navigation system is quite simple and straight forward.

Honeywell's LASEREF IV inertial reference system is an all-digital ring laser gyro-based inertial reference system. Figure 11-155.

Alignment is the process whereby the orientation of the axes of an inertial navigation system is determined with respect to the reference axis system. The IRS provides the inertial navigation data and the inertial flight control data to other systems.

Alignment is the process whereby the orientation of the axes of an inertial navigation system is determined with respect to the reference axis system.

The keyboard is used to initialize the system. • Section 8 introduces several methods for reducing drift in inertial systems.

Alignment is the process whereby the orientation of the axes of an inertial navigation system is determined with respect to the reference axis system.

Except this difference, the principles for alignment are quite the same.

Figure 11-155. Accurate alignment is crucial, however, if precision navigation is to be achieved over long periods of time without any form of aiding. Latitude and longitude position is displayed at the top. Alignment in-flight.