engleski

MACHINE USE OF S-101 CHARTS STORED IN THE DATABASE

In this article it is shown which possibilities are offered for machine inter- pretation of S- 101 chart data by storing it into a Postgres database. A good possibility of machine interpretation of the chart data is one of the prerequisites for autonomous navigation. Likewise, it is shown how data from multiple S-101 charts can be used simultaneously with the database structure used. Furthermore, it is shown with examples how to search the curves or points with certain feature codes (examples Coastline or BuoyIsolatedDanger ) in the database. Postgres GIS extensions are briefly explained. Different GIS object types are presented. The difference between geography and geometry types with im- pact on result of used functions is mentioned. The use of some Postgres GIS extension functions is described. Specifically, it is shown with examples how these functions can be used to check if our course could pass over an object or intersect a certain curve from the chart. When checking the possible crossing of a specified point, it is shown how a safety radius can be created around the point for the calculations. This radius can of course depend on various factors. After that, the exact calculation of the current distance to the cal- culated intersection point is also shown. The computational effort required for the execution of the presented GIS functions is estimated. Examples of C code used are also included.

S-101 charts, Autonomous ships, Postgres database, GIS exten- sions

nije evidentirano