Figure 90: Baseline Comparison - Applanix POS MV V5 Installation And Operation Manual

POS MV V5 Installation and Operation Guide
Theory
of Operation
Note: The example shown in Figure 90 is greatly simplified. It shows only the relative yaw angles made
by the baseline vectors. In practice, the transformation of one baseline vector to another may possibly
involve rotations in all three axis - roll, pitch and yaw.
Baseline Measurement
Geographic Antenna Baseline Vector
To compute a highly accurate value for Ф
resolve the phase ambiguities in the differential carrier phase observables.
The GNSS receivers in POS MV use the L1 GNSS signal, which has a carrier frequency of 1575.42 MHz
and a wavelength of 19 cm. You can consider the range between each GNSS satellite and a GNSS
antenna as an integer number of L1 wavelengths plus a fraction of a wavelength.
B-20

Figure 90: Baseline Comparison

Where: Ф = geographic antenna baseline vector - the
ANT
geographic vector of the line that joins the two
GNSS antennas; this vector varies as the
heading of the vessel changes
Ф = geographic IMU vector - the geographic
IMU
heading of the IMU x-axis; this vector varies
as the heading of the vessel changes
r Δ
= surveyed antenna baseline vector - the vector
12
that joins the two GNSS antennas; because
the IMU and the GNSS antennas are mounted
rigidly on the vessel, this vector remains fixed
ANT
based on carrier phase differential GNSS, GAMS must first
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