The new Seapath 20 GPS Compass from Kongsberg Seatex has achieved IMO type
approval from DNV, Norway as THD (Transmitting Heading Device) using GNSS
principle. The Seapath 20 replaces several vessel instruments with one
compact navigation package (gyrocompass, GPS system, speed log and
rate-of-turn indicator) that outputs heading, position, velocity and
rate-of-turn, together with 1-second time pulse (1PPS) for synchronization
of other survey systems.
The product comprises three components, a Sensor Unit, a Processing Unit
and a Display Unit. The Sensor Unit contains two GPS sensors and an
inertial sensor device. The Processing Unit contains the main CPU, a
number of individually configurable RS-232 or 422 output serial lines and
Ethernet. The Display Unit provides an LCD screen for navigation
information and push buttons for user control and command.
The precise heading information is not effected by the latitude and vessel
dynamics as with traditional gyrocompasses. Heading is derived from the
fixed-distance dual GPS antenna arrangement in the Sensor Unit based on
advanced phase measurements. The inertial sensor device in the Sensor Unit
provides yaw information. In case of short GPS outages, the inertial
sensor automatically takes over as the prime source for heading
determination until the GPS signals become reliable again. Working
together seamlessly, the inertial and GPS components of the Seapath 20
ensure accurate, continuous and robust heading information. The Seapath 20
offers the market a high precision
GPS compass providing an accuracy in
heading of 0.3° and up to 20 Hz update rate of heading, position and rate
of turn.