Abstract: This paper takes the updating of nautical charts as an example in the context of geospatial data updates,discussing the requirements and methods for currentness analysis during the process of geospatial data updates.It emphasizes the critical role of quantitatively assessing the currentness of coastlines in nautical chart updates and analyzes the limitations of existing currentness assessment procedures and traditional similarity assessment methods.In response to these situations,this paper proposes a method for assessing the similarity of linear features oriented towards coastal currentness analysis.This method mainly consists of three steps: Firstly,a resampling method considering the accuracy of linear features is designed for preprocessing the update data. Secondly,a workflow for extracting and transforming shape features of linear features is established to ensure consistency of feature extraction results across multiple scenarios such as mirroring,rotation,scaling,and translation. Finally,a criterion for judging the similarity of linear features based on shape feature extraction results is proposed,achieving quantitative comparison between updated and original data.Experimental results show that this method has strong robustness and the ability to match local line segments overall.By extracting the shape features of linear features,it realizes the quantitative evaluation of linear feature similarity,providing effective technical support for nautical chart updates.

Key words: geospatial data update, similarity algorithm, nautical chart update, linear similarity