TABLE OF CONTENTS Inertial navigation (Chapter 5) has a number of advantages. It operates continuously, bar hardware faults; provides high-bandwidth output at at least 50 Hz; and exhibits low short-term noise. It also provides effective attitude, angular rate, and acceleration measurements, as well as position and velocity. However, the accuracy of an inertial navigation solution degrades with time as the inertial instrument errors are integrated through the navigation equations, while INS capable of providing effective sole-means navigation for more than a few minutes after initial alignment are expensive at around $100,000 or 100,000 Euros.
GNSS (Chapters 6 to 8) provides a high long-term position accuracy with errors limited to a few meters (stand-alone), while user equipment is available for less than $/ 100. However, compared to INS, the output rate is low, typically around 10 Hz, the short-term noise of a code-based position solution is high, and standard GNSS user equipment does not measure attitude. GNSS signals are also subject to obstruction and interference, so GNSS cannot be relied upon to provide a continuous navigation solution.
The benefits and drawbacks of INS and GNSS are complementary, so by integrating them, the advantages of both technologies are combined to give a continuous, high-bandwidth, complete navigation solution with high long- and short-term accuracy. In an integrated INS/GNSS,...
