Beginning with the version 3.0, the SDK supports Inland ENC. No additional functions are required in order to support Inland ENC in OEM’s code.
Portrayal Specification Description – General
The IENC Portrayal Specification defines symbols and rules for the display of vector IENC datasets
and supports IENC 2.1, 2.2, 2.3 and 2.4 product versions. It is based on the IHO ECDIS PRESENTATION LIBRARY 4.0.2 (July 2017)
and IENC Portrayal specifications endorsed by Inland ENC Harmonization Group.
NAVTOR IENC presentation library uses Version 2.4 of IENC Portrayal specifications.
IENC Vector Products
NAVTOR IENC Presentation Library supports the following approved IENC Specifications:
- IENC base cells
- IENC Overlay cells
- IENC Bathymetry cells (bIENC)
Overlay and Bathymetry cells are to be displayed in conjunction with the base IENC cells.
Object and Attribute Catalogues
NAVTOR IENC Feature and Attribute Catalogue (ienc.fct) is compatible with IENC Feature Catalogue Edition 2.4 (Corr.2), 2015 Oct 30.
Product Specification Values for IENC Vector Products
The following Product Specifications values (PRSP subfield of DSID field) are used:
| Product Name |
PRSP value |
| IENC base cells |
10 |
| IENC Overlay cells |
10 |
| IENC Bathymetry cells |
200 |
Intended Usage (Navigational Purpose)
IENC data are compiled for a variety of navigational purposes. The navigational purpose for which an individual IENC has been compiled
is indicated in the “Data Set Identification” [DSID] field, “Intended Usage” [INTU] subfield and in the name of the data set files.
The following INTU values are defined:
| Navigational purpose |
Value (INTU) |
Intended usage |
Comments |
| Overview |
1 |
For route planning and oceanic crossing. |
S57 |
| General |
2 |
For navigating oceans, approaching coasts and route planning |
S57 |
| Coastal |
3 |
For navigating along the coastline, either inshore or offshore |
S57 |
| Approach |
4 |
Navigating the approaches to ports or mayor channels or through intricate or congested waters. |
S57 |
| Harbour |
5 |
Navigating within ports, harbours, bays, rivers and canals, for anchorages. |
S57 |
| Berthing |
6 |
Detailed data to aid berthing. |
S57 |
| River |
7 |
Navigating the inland waterways. |
IENC |
| River harbour |
8 |
Navigating within ports and harbours on inland waterways. |
IENC |
| River berthing |
9 |
Detailed data to aid berthing maneuvering in inland navigation. |
IENC |
IENC Overlay and Bathymetry cells should be displayed in conjunction with the base IENC cells within a range of usages.
The range of usages of the overlay and bathymetry cells display is indicated in the Data Set Identification Field of the header.
The 8-th bit of the intended usage subfield (INTU) in this case is set. The other seven bits describe the range:
| Definition of range |
from |
to |
| Mathematical description |
(INTU-128) div 10 |
(INTU-128) mod 10 |
| Example (INTU=207) |
(207-128) div 10 = 7 |
(207-128) mod 10 = 9 |
Intended Usage to Display Scale Conversion
In NAVTOR IENC presentation library, correlation between an intendent Usage and Display scales for IENC,
Overlay and bathymetry cells is defined in sdk_config.xml in a special table
(section //).
The values for Max and Min Display scale are set as it is shown in the table below and may be changed if necessary:
| Navigational purpose |
Value (INTU) |
Min Display scale |
Max Display scale |
| Overview |
1 |
1:147483647 |
1:1499999 |
| General |
2 |
1:1499999 |
1: 350000 |
| Coastal |
3 |
1: 349999 |
1: 90000 |
| Approach |
4 |
1: 89999 |
1: 22000 |
| Harbour |
5 |
1: 40000 |
1: 4000 |
| Berthing |
6 |
1: 30000 |
1: 3000 |
| River |
7 |
1:25000 |
1:1000 |
| River harbour |
8 |
1:25000 |
1:500 |
| River berthing |
9 |
1:15000 |
1:1 |
Such special processing of IENC Intendent Usage may be excluded for certain Data providers. For this purpose necessary agency codes (see S-65 and NAVTOR data_producer_codes.json)
should be listed in section // and the value of the attribute
In such case the above table for Max and Min Displayed scales will be ignored and IENC cells for defined providers will be processed as usual
ENC according to the Compilation scale of a Dataset.
IENC Symbology
IENC symbology is based on IHO presentation library version 4.0.(2) and of IENC Prtrayal specifications, version 2.4.
Portrayal Parameters
According to IENC Presentation library specifications, Notice marks should be displayed with general or detailed shapes.
Default mode for presentation is general shapes. To show them in detailed mode it is necessary to set Portrayal parameter ‘DetailedNoticeMarks’ to {1}..
Viewing Group Implementation
IENC information level (Objects and Attributes catalogue) consists of the standard S-57 and the specific for IENC objects and attributes - special IENC objects.
Special IENC objects can be the following types:
- So-called copied objects (attributes). These are objects (attributes) copied from S-57, but these objects (attributes) can contain new attributes and new attribute values.
The acronym of such an object (attribute) is the same as in S-57, but is defined with lower case letters. For example, boylat – buoy lateral, is the copied S-57 object BOYLAT.
This object has a copied attribute catlam – category of Lateral mark, instead of CATLAM S-57 attribute.
- Specific IENC objects (and attributes). It is, e.g., Waterway axis (wtwaxs) object.
Standard S-57 objects in IENC have the same Viewing groups as in the S-52 Presentation Library and should be processed as usual.
Special IENC objects have their own Viewing Groups defined in IENC presentation library, edition 2.4.
They are also subdivided into Base, Standard and Other display groups as it is done in S-52.
It is necessary to underline that unlike S-52 Buoys, beacons, structures and Ships' routing objects should be shown on the Base but not on the Standard display.
Structure of IENC Viewing groups (VG)
General structure of IENC Viewing groups (VG) is the following:
| Inland Waters |
VG = 2000000 |
| |
Inland Waters, Base |
VG = 2100000 |
| Inland Waters, Standard |
VG = 2200000 |
| Inland Waters, Other |
VG = 2300000 |
Structure of IENC Base display VGs is the following:
| Inland Waters, Base |
VG = 2100000 |
| |
Buoys, beacons, structures |
VG = 2110000 |
| |
Buoy, lateral |
VG = 17010 |
| Beacon, lateral |
VG = 17020 |
| Notice mark |
VG = 17030 |
| Ships' routing |
VG = 2120000 |
| |
Radio calling-in point |
VG = 15060 |
Structure of IENC Standard display VGs is the following:
| Inland Waters, Standard |
VG = 2200000 |
| |
Landmarks and structures |
VG = 2210000 |
| |
Bunker station, Refuse dump, Harbour facility, Vehicle transfer |
VG = 22410 |
| Terminal |
VG = 22420 |
| Distance marks |
VG = 2220000 |
| |
Distance marks |
VG = 22430 |
| Special areas |
VG = 2230000 |
| |
Turning basin |
VG = 26020 |
Structure of IENC Other display VGs is the following:
| Inland Waters, Other |
VG = 2300000 |
| |
Miscellaneous |
VG = 2330000 |
| |
Waterway axis, Waterway profile |
VG = 31050 |
