POS MV V5 Installation and Operation Guide
Theory
of Operation
Copyright © Applanix Corporation, 2017
B-5
Figure 81: Example of INS Navigation on a Spherical Earth
In Figure 81, the vessel that supports the INS has no applied angles of roll or pitch, and moves along a
fixed northerly heading.
Ideally, the INS platform defines a navigation frame that is both locally stable and locally level:
•
A
locally stable reference frame
always maintains a constant orientation relative to the surface of
the Earth at its current position.
•
A
locally level reference frame
is always level relative to the surface of the Earth at its current
position.
In Figure 81, the navigation frame of the vessel coincides with the geographic frame of reference.
Inertial Navigation Frames of Reference
This appendix refers to a number of different frames of reference:
•
Inertial
frame
•
Earth
frame
•
Geographic navigation frame
•
Body
frame
•
IMU body frame
For clarity, the following subsections define each of these reference frames as they apply throughout this
appendix.