A study of optimal target´s position in ARPA system

Automatic Radar Plotting Aids (ARPA) is one of instruments for safe navigation, and ARPA system needs some input data to calculate ARPA information, which are own ship´s course, own ship´s speed and a target position (ARPA position). Here, a target position of radar echo signal reflected from a target is fluctuating scan to scan and pulse to pulse. We think that this fluctuation influence an accuracy of ARPA information. We propose four kinds of ARPA position, and an optimum position in ARPA system is the nearest point to own ship in the centerline bisecting the echo signal or area center point in our study. In short, four target positions are 1) Peak point, 2) Center point 3) Nearest point, 4) Area center point. Also, radar echo signal is collected from Training Ship FUKAE-MARU in Kobe University of Mercantile Marine (KUMM) off marine practical center by using radar signal analysis system of our research room. We carried out ARPA simulation by using distribution function of our ARPA positions fluctuation measured.