确保水深模型航海安全性的深度保证率控制方法

Control method of probability of adequate depth ensuring navigation safety of depth model

针对当前海图水深应用在保证航海安全方面的不足,提出了海图水深的深度保证率控制方法,确保水深模型服务于航海的安全性。利用海图水深注记点,建立不规则三角网水深模型表面,推导了模型表面任意位置水深的整体计算公式。在考虑水深源数据不确定度对航海安全影响的基础上,定量分析了水深模型在任意位置处描述不确定度的影响。通过在模型点上附加不确定度来控制描述不确定度的影响,将水深模型的深度保证率控制在规定要求之内。在比例尺分别为1∶2 000、1∶5 000、1∶10 000、1∶50 000的海图上,对提出的面控方法进行验证,并与传统方法、点控方法进行了对比。分析结果表明:与传统方法相比,在4种海图上,面控方法深度保证率的合格率分别提高了51.72%、49.37%、38.71%、28.39%;与点控方法相比,面控方法分别提高了4.10%、5.00%、5.06%、9.65%;随着比例尺减小,传统方法深度保证率的合格率有所提高,点控方法有所下降,而面控方法因为综合考虑了源数据不确定度和模型描述不确定度的影响,深度保证率的合格率始终保持为100%;面控方法能将深度保证率控制在规定指标(97.5%)范围内,而传统方法和点控方法均不能达到规定指标,说明了面控方法的优越性。

Considering the drawback of charted depth in ensuring the navigation safety currently,a control method of probability of adequate depth was proposed,thus the navigation safety of depth model was ensured.The surface of triangulated irregular network（TIN）-based depth model was constructed based on the mark point of charted depth,and the common formula for calculating the depth of model surface at arbitrary position was deduced.Considering the influence of uncertainty of depth source data on navigation safety,the influence of representation uncertainty of depth model at arbitrary position was analyzed quantitatively.The uncertainty was appended on the model point to control the influence of representation uncertainty,and the probability of adequate depth of depth model was controlled to meet the required value.On the charts with the scales of 1∶2 000,1∶5 000,1∶10 000,1∶50 000,respectively,the proposedsurface control method was verified and compared with traditional method and point control method.Analysis result indicates that the acceptable rates of probability of adequate depth controlled by using surface control method on the charts are respectively 51.72%,49.37%,38.71%,28.39% higher than the rates by using traditional method,and are 4.10%,5.00%,5.06%,9.65% higher than the rates by using point control method.When the scale decreases,the acceptable rates of probability of adequate depth controlled by traditional method increase,and the rates by using point control method decrease,however,the rates by using surface control method are always 100% for both considering the uncertainty of source data and the representation uncertainty of depth model.The probability of adequate depth controlled by surface control method meets the required value（97.5%）,but traditional method and point control method cannot satisfy the demand,which demonstrates the advantages of surface control method.3tabs,9figs,25 refs.