Working with S-63 Electronic Nautical Chart Data
This guide describes how the S-63 support in Carmenta Engine works. At the end you can find links to step-by-step examples of some typical use cases.
In short, the S-63 standard, published by the International Hydrographic Organization (IHO) specifies a protection scheme for S-57 Electronic Nautical Chart (ENC) data. It allows for data producers to encrypt their data and only provide decryption keys for clients that have purchased a license for using the data. It also makes it possible for clients to validate that the ENC data originates from trusted data producers, that have been approved by the IHO.
Carmenta Engine supports versions 1.1, 1.1.1 and 1.2.0 of the S-63 specification.
S-63 support in Carmenta Engine
The S-63 support in Carmenta Engine consists of two parts:
The first part is a definition of a Carmenta Engine S-63 database, and a number of classes in the API for creating and maintaining such a database. The database is stored in a directory on the client's hard drive.
The second part is additions to the S57DataSet class to make it read from an S-63 database instead of unencrypted S-57 files.
An application that wants to read and display S-63 ENC data may incorporate the necessary code to maintain a database on the local hard drive. But it can also choose to put this support in a standalone utility program that the end user can run independently from the application whenever he wants to update or add new S-63 data. In fact, the Carmenta Engine SDK includes such a utility, S63Manager.exe or S63Manager64.exe on Windows or carmenta-s63-manager on Linux. It's a very simple command line tool, but it gives a user direct access to the important functions in the API.
The S-63 user permit
The S-63 scheme dictates that licensing of data is done independently for each client. The encrypted data may be distributed and copied to multiple machines, but the licenses, or permit files, needed to decrypt the data must be unique for each client. To implement this, each client must be assigned a unique hardware ID. The hardware ID is coded into a character string called a user permit.
Carmenta Engine implements this by assigning an ID for each client and adding it to the regular Carmenta Engine license file. Since it must not be shared among different clients, this means that every Carmenta Engine license with an S-63 hardware ID, even runtime licenses, must be activated and locked to a specific client machine just like the SDK licenses usually are. See Using a Carmenta Engine 5 runtime license for details.
Purchasing licenses to use S-63 data
Like stated above, this must be done separately for each client that will need to read and display the ENC data. S-63 data is supplied by data servers, typically on CDs or DVDs, or through online download. The client must then purchase the licenses for the data it needs to use. To do so, it must supply its user permit. The data server will then provide the client with the necessary permit files to unlock the licensed data. Thanks to the hardware ID embedded in the user permit, the permit files will not be usable for any other client.
Managing the S-63 database
The central class in the Carmenta Engine S-63 API is the S63 class. It has the necessary methods to create a new database or open en existing one, and to import permit files and register S-63 data files. It also has a static property to retrieve the client's user permit. Please see the SDK reference documentation for this class for details.
An important point here to notice is that the S-63 data, distributed as exchange sets, is not copied into the database; only the location of the data is saved. This means that the exchange sets that are registered in the database must remain available to the application from the same location, until newer versions of same same ENC cells replace the older ones. If possible the path to the exchange set data are stored as a path relative to the S-63 database. In contrast, the permit files are copied into the database, and can be removed after they have been imported.
The S-63 scheme specifies a number of errors and warnings that must be given in certain error situations, for instance when a permit file has expired. Several methods in the S63 class therefore return lists with warning messages detected during the operation; it is up the application to display these to the end user.
Using an S-63 database
The S57DataSet is used for reading both unencrypted S-57 files and S-63 data from a database. To use it in S-63 mode, simply specify the S57DataSet.S63DatabasePath property to point to the location of the database. In this case, the path and filename properties of the dataset will be ignored. Otherwise the dataset works the same in both cases, and an S52Visualizer can be used to visualize the chart data.
Examples
Below you will find links to some step-by-step examples of typical use cases.
Note that the utility programs S63Manager and RuntimeLicenseKeyManager referred to in the examples are used with their 64-bit Windows names. On Linux these are called carmenta-s63-manager and carmenta-runtime-license-key-manager, respectively.
Example 1 - Using S-63 data with a Carmenta Engine SDK
Example 2 - Deploying an S-63 application with Carmenta Engine runtime