Evaluation of Automatic position Fixing System on Tanker "SEIKO-MARU"

Abstract

The 138, 000 DWT tanker "SEIKO-MARU" is the first computerized vessel in Japan. The automatic position fixing system of this vessel consists of a NNSS (Navy Navigation Satellite System) receiver and a Dead Reckoning Position Calculator (DRPC), and these two equipments are connected to the same central computer, TOSBAC 3000S. Authors obtained the records from this system at sea, and evaluated the following items ;- (a) frequency of the position determination by NNSS, (b) difference of the dead reckoning position by DRPC from the NNSS position, (c) state of scattering of the NNSS position from a straight course line, (d) state of spreading with time of the dead reckoning position by DRPC.