Kongsberg Seatex Seapath 200, Installation Manual

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Seatex Seapath 200 Installation Manual, rev. 13 Introduction
3
1.3.2 Abbreviations and acronyms
b-frame
Body frame. An orthogonal frame fixed to the MRU housing or to the
vehicle where the MRU is fixed.
CEP
Circular Error Probability.
CG
Centre of gravity. The mass centre of a vessel. This is normally the location
with least linear acceleration, and hence the best location for measurements
of roll and pitch.
EMI
Electromagnetic interference.
g-frame
Geographic frame. An orthogonal frame having axes pointing North, East,
and Down at the current location of the vehicle.
GPS Time
The time in the GPS system. The GPS time is within UTC time
±
180 nsec
(95 per cent) plus leap seconds.
IMU
Inertial Measurement Unit. A system consisting of gyros and
accelerometers.
LGND
Logic Ground.
MP
Measurement Point.
MRU 5
Motion Reference Unit, model 5. This is the IMU within the Seapath
measuring dynamic linear motion and attitude.
NMEA
National Marine Electronics Association. NMEA 0183 is a standard for
interchange of information between navigation equipment.
P-axis
This axis is fixed in the vehicle, and points in the starboard direction
horizontally when the roll angle is zero. Positive rotation about this axis is
bow of the vehicle up.
PGND
Power Ground.
PPM
Parts per million.
1PPS
One Pulse Per Second.
RFI
Radio Frequency Interference.
RMS
Root Mean Square.
R-axis
This axis is fixed in the vehicle, and points in the forward direction
horizontally when the pitch angle is zero. Positive rotation about this axis is
starboard side of the vehicle down.
SBAS
Satellite Based Augmentation System
SCC
Seapath Control Centre is special software used to set configuration
parameters in Seapath. The software runs under Microsoft Windows version
95, 98, NT 4.0 or compatible on a PC.
UTC
Universal Time Co-ordinated. This is the official time in the world and has
replaced GMT (Greenwich Mean Time) as the official time.
Y-axis
This axis is fixed in the vehicle and points in the downward direction when
the vehicle is aligned horizontally. Positive rotation about this axis is
turning the bow of the vehicle to starboard.