CARIS HPD : HPD® User Guide : Schema Configuration : Sub-Agencies
 

Sub-Agencies

You can set up sub-agencies in HPD and assign ranges of feature object IDs to them.

The S-57 data model uses feature object IDs as alphanumeric identifiers to differentiate one feature from another.

A feature object ID is composed of the following parts:

Agency: A two-character code based on the International Hydrographic Organization (IHO) agency producer scheme.

Identifier: A number between 1 and 232 (4,294,967,294 or about 4 billion) that is incremented by 1 each time a new object is added to the database.

Subdivision: A number between 1 and 216 (65,536) used to group the above identifiers.

Example

For example, the feature object ID 1C 0000039802 00003 is composed of:

Agency code 1C

Identifier 39802

In subdivision 3

Subdivisions of feature object IDs can be assigned to different sub-agencies. For example, one sub-agency might be assigned subdivision ranges 1 to 10 and another assigned ranges 11 to 20. This ensures that all sub-agencies generate unique feature object IDs.

If the identifier number ever reaches the maximum value, it is reset to 1 and the subdivision value is incremented by 1. This assumes that the ending subdivision number for the current sub-agency range has not been reached.

When a new HPD schema is created, only one sub-agency range is created, covering the full range of available values from 1 to 65,536.

After installation, the Administration Tools programs can be used to control agency and sub-agency settings:

For each HPD sub-agency value, the initial identifier number is set to 1. Currently, there is no way to assign the next available identifier for a user account.

Related commands: