Development of Software Structure for Integrated Navigation Receivers in Shipping

Abstract Important issues for automation of shiphandling are accuracy, availability and reliability of position, velocity and time. In most cases there are satellite navigation receivers as the primary position fix system. Accuracy of satellite navigation receivers onboard ships can be affected by shadowing from obstructions, reflections, multipath, satellite changings, ship’s movements or ship’s maneuvering. Various means of increasing accuracy, availability and reliability are examined using integrated solutions with: (D)GPS/(D)GLONASS with ship dynamic identification or their combination with LORAN-C. A reliability check should be done using ranges to satellites or, better yet, by ranges to a terrestrial system. More accurate measurement of ship’s velocity (compared to electromagnetic or Doppler log) can be accomplished using GPS, DGPS or an integrated solution. Parameters that can be integrated into a position solution include: terrestrial navigation systems; a second satellite navigation system; ship parameters (rudder angle, propeller speed, gyro heading); and, environmental parameters (wind, current). These parameters lead to a more accurate prediction of position and ship dynamics.