Figure 88: Heave Filter Transient Behaviour With Damping Ratio - Applanix POS MV V5 Installation And Operation Manual

Figure 88 shows a plot of the heave filter response against time for four damping ratios at the default
heave bandwidth of 20 seconds. The filter settling time is for the impulse response to settle to 20% of the
impulse magnitude.
GNSS Azimuth Measurement Subsystem
POS MV delivers heading measurements with an optimal accuracy of ±0.02°. It does this by using two
distinct and independent methods:
1. Dynamic Heading Alignment - A method that uses data supplied by the IMU and GNSS receivers
to achieve a heading that is, at best, accurate to within 0.35°.
Dynamic heading alignment delivers its best performance when the measurement unit
experiences rapid changes of direction and varying forces of acceleration. Drift will begin to
appear in the heading measurements when these dynamic manoeuvres cease and the vessel
follows a steady course and speed.
2. GNSS Azimuth Measurement Subsystem (GAMS) - A system that determines the geographic
vector between two GNSS antennas fixed to the vessel. It does this by comparing the phase of
satellite signals arriving at each antenna.
You can expect carrier phase differential measurements to deliver differential range
measurements with an accuracy of between two and 10 millimetres, and heading measurements
with an accuracy of between 0.1° to 0.5° RMS. These specifications are typical of multi-antenna
Copyright © Applanix Corporation, 2017
POS MV V5 Installation and Operation Guide

Figure 88: Heave Filter Transient Behaviour with Damping Ratio

Theory
of Operation
B-17