Instructions for use

In the S-57 data structure, each instance of a feature object class (which can be understood as an object object, such as a light) is stored using a feature record, and a feature object identifier (FOID, that is, a long name) is assigned as Unique Identification, but the water depth is a special case. There may be a large number of water depth points in a chart, and many water depth points have the same attributes and attribute values except depth. If each water depth point is stored as a feature record, a large number of redundant data will be produced, and even the efficiency will be affected. Therefore, in the S-57 data structure, water depth points with the same attributes and attribute values (except depth) are synthesized into one feature record.

In the SuperMap chart, the water depth is stored as a feature Object Type in a feature object Dataset, in which each water depth point is an object. Therefore, a water depth feature record in the S-57 data may correspond to multiple water depth point objects in the SuperMap chart. The process of assigning water depth points with the same attributes and attribute values (except depth) to a new FOID and RCID is called water depth grouping.

Chart Edit module provides editing functions for water depth points, such as automatically dividing water depth groups, adding water depth points to water depth groups, deleting water depth points from water depth groups, and modifying the attributes of water depth objects. In this chapter, the depth point editing function is described in detail.

Executive summary:

This section describes how to add or delete a water depth point.

This paper introduces the specific operation of editing and modifying the attributes of water depth grouping, which can be used to set the attributes other than depth value at the water depth point.

The specific operation of editing the depth value of the water depth point is introduced.