OBSERVATION OF K-DISTRIBUTED SEA CLUTTER VIA AN X-BAND RADAR

In radar signal processing, it is important to eliminate unwanted nois e called clutter and to detect the desired target so that the degree o f discrimination is improved. To this end, the statistical characteris tics of the clutter have been investigated. In such instances, it is n ecessary to have a process which obtains a constant false alarm rate ( CFAR). In this paper, the amplitude intensity distribution of the sea clutter measured by an X-band radar is studied quantitatively by means of the Akaike Information Criterion (AIC) under an assumption that th e intensity distribution is Weibull, log-normal and K-distributions, I t is confirmed that, for a high sea state with wave height of 6 to 9 m and wind velocity of 25 m/s, the sea clutter follows a log-normal dis tribution as a whole and a K-distribution within the antenna beamwidth . With regard to the CFAR circuit by normalization of the standard dev iation which is considered effective for suppression of the clutter fo llowing a Weibull and a log-normal distribution, a CFAR processing was carried out with both Monte Carlo simulation and raw data. From the r esults of computer simulation, it was confirmed that the CFAR circuit is effective for suppression of clutters following a K-distribution. A lso, by processing the raw data by this circuit, it was successful in correctly detecting targeted ships while the clutter was suppressed.