OGC standard Introduction 2

I. SFS-
Simple Element standards-Overview

The current version of SFS (OpenGIS Simple Features Interface Standard) is 1.2.0. In fact, SFS includes two parts. The first part is a general model that describes simple elements (Part 1: common architecture
). The other part describes the implementation of the previous model in SQL (Part 2: SQL Option
) [1]
. The well-known WKT and WKB are described in the first part, while the common astext and intersects operations in spatial SQL statements are defined in the second part.

The following describes important content in SFs in detail, including the geometric object model in the first part, the geometric object described by WKT, the geometric object described by WKB, the spatial reference of WKT, and the SQL predefined schema, SQL geometric type, and SQL space in the second part. operation.

· Geometric object model

Figure
1. geometric object model defined in SFs

Figure 1 shows the relationship structure of geometric objects in SFs. The geometric objects in simple elements mainly define points, lines, faces, and multiple points, multilines, and multiple faces. In addition, geometric objects also involve a series of operations, as shown in figure 2.

Figure
2 Geometry operations

[1]
The current version does not support the implementation of CORBA and OLE/COM.