A Study on the Accuracy of ARPA Information

Abstract

Automatic Radar Plotting Aids (ARPA) is one of the instruments effective for aiding safe navigation in term of collision avoidance. The ARPA informations are well utilized and highly appreciated among watch officers especially when the visibility is limited. But we should remember that the ARPA is not complete yet. It still suffers transfer of target, lost target and other information mishap from time to time. So it remains necessary to study on the accuracy of the ARPA informations. In summer of 1994, we worked on the collection of the radar echo signal data reflected from T. S. FUKAE MARU at 36 aspect angles in smooth sea condition off Marine Practice Center of our school in Awaji island. The received signals are processed by the 8bits, 120MHz A/D converter and stored in the 8 Mbytes memory to find a basic statistical characteristics of the radar echo. In this paper, we propose a Monte-Carlo analysis for the evaluation of the reliability of ARPA information in which the effect of fluctuating target positions on the estimated course is simulated and analysed based on the distribution functions of the fluctuation of the collected peak positions obtained as mentioned above.