近海船长分布建模与雷达舰船分类能力评估

Ship length distribution modeling on China offshore and ability evaluation of radar ship classification

雷达高分辨距离像径向尺寸估计和航向角估计是舰船分类的主要技术手段,其分类性能与雷达分辨率、径向尺寸估计精度以及不同海域的舰船长度先验分布密切相关。通过中国船讯网采集了我国近海四大海域约30000艘舰船的船舶自动识别系统信息,并提取了舰船长度数据。通过对舰船长度的分布拟合,发现韦布尔分布能够很好地拟合各海域的船长分布,且分布参数有明显差异。基于该先验模型,推导出了舰船的大、中、小正确分类概率与径向尺寸估计误差之间的关系。结果表明,当舰船航向角介于±75°之间时,我国近海舰船的大中小正确分类概率达到90%的条件是,舰船径向尺寸估计误差在区间(-12.67 m,9.41 m)内。

Radial size estimation using radar high-resolution range profiles(HRRPs)and heading angle estimation are the main means for ship classification.The classification ability is closely related to the range resolution of the radar,precision of radial size estimation,and prior distribution of ship lengths in different offshore areas.We collected the AIS information on about 30000 ships and their lengths in the four offshore areas of China in the ship information net of China.By fitting the data of ship lengths in each offshore area,it is found that the Weibull distributions provide good-of-fitness to the ship lengths and the parameters in individual area are rather different.Based on the prior distributions of ship lengths,we derived the quantitative relationship between the correct classification probability of big-moderate-small ships and the estimate error of ship radial size.The results indicate that the condition for the big-moderate-small correct classification probability in the offshore areas of China to be up to 90% is that the estimate errors of the ship radial size estimates falls into the interval(-12.67 m,9.41 m)when the heading angle of the ship is between ±75 degrees.