The GPS CompassThe Seapath 20 product is a GPS compass that provides true heading output with no moving parts. TheSeapath 20 replaces several vessel instruments with onecompact navigation package (gyrocompass, GPS system,speed log and rate-of-turn indicator) that outputs head-ing, position, velocity and rate-of-turn, together with 1-second time pulse (1PPS) for synchronization of othersurvey systems.

Flexible components

The product comprises three components, a Sensor Unit,a Processing Unit and a Display Unit. The Sensor Unitcontains two GPS sensors and an inertial sensor device.This unit is to be mounted in the vessel mast. TheProcessing Unit contains the main CPU, a number ofindividually configurable RS-232 and 422 output seriallines and Ethernet. The Display Unit provides a LCDscreen for navigation information and push buttons foruser control and command.

Perfect accuracy

The precise heading information is not effected of thelatitude and vessel dynamics as traditional gyro com-passes. The heading is derived from the fixed-distancedual GPS antenna arrangement in the Sensor Unit basedon advanced phase measurements. The inertial sensordevice in the Sensor Unit provides yaw information. Incase of short GPS outages, the inertial sensor automati-cally takes over as the prime source for heading determi-nation until the GPS signals again are reliable. Workingtogether seamlessly, the inertial and GPS components ofthe Seapath 20 ensure accurate, continuous and robustheading information. Optionally, the Seapath 20 can bedelivered with an IALA beacon receiver to ensureimproved position accuracy when DGPS signals areavailable.

Easy to install and operate

The Seapath 20 requires no scheduled maintenance or re-calibration. The product offers a flexible configuration ofthe outputs and interface setups, depending on the vesseland application. It is easy to operate, install and align.

Type approvedThe Seapath 20 is IMO type approved by DNV, Norwayas THD (Transmitting Heading Device) using GNSSprinciple.

Seatex Seapath™ 20

KONGSBERG SEATEX ASPirsenteret N-7462 Trondheim Norway Telephone +47 73 54 55 00 Telefax +47 73 51 50 20 firmapost@kongsberg.com www.kongsberg.com

Features

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Sensor Unit

Display Unit

ProcessingUnit

EthernetRS232/422 output

RS232/422 output

RS232/422 output

DGPS input

1PPS/Radar output

• True heading anywhere on earth

• Heading accuracy unaffected of the latitude

• Heading available in periods of GPS drop-outs

• Replaces several instruments with one robust, integrated product

• Accurate heading during and after turns compared to heading from standard gyrocompasses

• Only two-pair cable (no coax) between the mast unitand the Processing unit on the bridge.

• 20 Hz update rate on heading, rate of turn and position measurements

• Three RS-232 and three RS-422 configurable outputserial lines and Ethernet

• 1PPS output for synchronization of other surveyequipment

• Accurate and responsive heading source to a favorable price

Performance (*)

Heading accuracy 0.4° RMSHeading resolution 0.01° RMSHeading operational measurement range Roll/pitch within ±30°Rate of turn accuracy 0.5º/s + 5%Maximum turn rate 80º/sPosition accuracy with DGPS 1.5 m RMS or 3.3 m 95% CEPVelocity accuracy with DGPS 0.05 m/s RMS or 0.1 m/s 95% CEP

Data outputsCommunication ports 3 RS232 and 3 RS422 serial lines and Ethernet UPD/IPData output rate Up to 20 HzBaud rate 38.4k baud (max)Output message formats NMEA 0183 ZDA, GGA, GLL, VTG, HDT, ROT, GSA, GRS

and proprietary messages PSXN 20, RD Instrument ADCPproprietary NMEA format, "PRDID".

Clock Data 1PPS or AD-10 format (Simrad or Furuno radar compatible)

Data inputsCommunication ports 1 RS232 and 1 RS422 serial lineBaud rate 38.4k baud (max)DGPS corrections RTCM-104 version 2.2

Dimension and weightProcessingUnit 287 (w) x 203 (h) x 60 (d) mm, weight 1.3 kgDisplay Unit 220 (w) x 110 (h) x 39 (d) mm, weight 0.5 kgSensor Unit 850 (w) x 205 (h) x 262 (d) mm, weight 8.0 kg

Operating temperatureProcessing Unit 0 to +55ºCDisplay Unit 0 to +55°CSensor Unit -30 to +55°C

PowerProcessing Unit 10 to 32 VDC, 15 W

HumidityProcessing Unit IP-44Display Unit IP-56 from front, IP-43 from backSensor Unit IP-65, hermetically sealed

(*) The performance figures are valid with a minimum of four visible satellites, HDOP less than 4, PDOP less than 6, and otherwise normal conditions. Excessive multipath, GPS signal obstructions or interference may reduce the performance.

The specifications can be changes on short notice

Technical specifications