Estimating quality indices of a digital depth model for navigational safety

To ensure safe ship navigation, true water depths should be deep enough with respect to the corresponding depths on a chart. Therefore, a set of basic quality indices, including an index of the probability of adequate depth, were developed to evaluate the quality of a digital depth model (DDM) with respect to navigational safety. In addition, these methods are proposed for assessing the probability of adequate depth and the percentage of acceptable probabilities, the deep-bias displacement. Theoretical analysis and experimental comparisons presented in this paper demonstrate that the defined indices can be used to evaluate quantitatively the quality of a DDM in terms of the navigational safety.