Lossless Transformation

The crew of a merchant ship is like a small fighting unit. Every voyage they undertake is like a campaign. The Master is the commander who has to win the battle regardless. No wonder these people hardly ever interact with the rest of the shipping industry because they are too engrossed in their own battles.

I have noticed that it is very difficult to engage the sailing staff to take part in conferences. Most such events are dominated by the OEMs, educators and the authorities.

So whatever little feedback we get from the operational seafarers is bonus and should be brought to the notice of all those who matter.

The other day I read this honest feedback from a sailing Master –

I believe that as electronic charts get more popular, their costs will automatically drop (the GPS way - down from 2000$ to 50 $!)It is left to us Masters to convey this (let us use our marketting skills, gentlemen!) to owners / reps - during their visits on board, to supers, and of course in the ultimate ISM tool - Masters review!As far as costs go, an ECS (non compliant with solas, but equal features as ecdis) is a commercially viable option - about 1.5-2 lakh installation per vessel. An ecdis will set you back aout 10 times this cost, ut is a good investment future wise.EU will be making it mandatory for larger tankers by 2010 to carry ecdis, Norway has already done this for it's fast ferries.

This feedback appeared in an ecdis forum. Those who are interested may visit http://groups.yahoo.com/group/ecdis/. It is a forum for sharing your experience in Ecdis with others.

Lossless Transformation

What do they mean by lossless transformation of the ENC?

I was taking an Ecdis class when someone asked this question referring to the changed definition of System ENC in the new Ecdis Performance Standards.

In the old definition, SENC meant the conversion of the S-57 (ASCII) ENC into a binary form which is basically the internal format of a computer. To this were added external data like ARPA, AIS and user info before the complete database was displayed on the screen.

It was assumed that the conversion of ENC to SENC would be carried out within the Ecdis kernel. In actual practice there are two major problems encountered in this method.

Firstly most ENCs are not error-free. They originate from different countries and subject to different standards of quality. So when onboard the ship the navigator carries out the conversion operation he gets frequent errors on his system. At this stage what is the point of getting such errors when there is nothing much he can do.

Secondly it is an extremely lengthy procedure to carry out this operation on board. The whole process could take as much as ten hours before the charts are ready to be run on the Ecdis.

There is no argument that the ASCII format of ENC has to be converted into a binary form for it to be recognized by the computer. The question was how to overcome the above problems.

In the late nineties C-Map proposed that the data conversion could be carried out outside the Ecdis. The charts could be tested in lab conditions. The customer is then given this error-free ENC data, in binary form, to be directly run on the Ecdis.

Initially this method of distributing ENC was mooted in 1998 at an IHO meeting at Singapore. However, some HOs objected to it. Later in 2002 at Valparaiso this issue was once again debated. This time Tor Svanes of C-Map Norway and Chris Anderson of National Imagery and Mapping Agency (NIMA), USA were able to convince the majority to adopt the SENC method of distributing ENCs.

In 2002, the IHO CHRIS committee passed the resolution TR 3.114 approving the distribution of ENC in SENC format as follows:

It is resolved that SENC distribution can be accepted as an option, in addition to direct ENC distribution, providing that the following principles be adhered to:
- The HO should ensure that the ENC is always available to any user in the S-57 ENC format.
- As an option HOs may allow the distribution of their data in a SENC format.
- Service providers who are to supply the SENC service must operate under the regulations of the issuing authority. The onshore ENC to SENC conversion must be performed using type-approved software.
- The SENC update mechanism should not be inferior to the ENC-ECDIS update mechanism.
- The distributor of SENC data should maintain a registry of its users.
- The copyright of the ENC data should be maintained.

In December 2006 the new Ecdis PS was brought out wherein the SENC was redefined as the manufacturer’s internal Ecdis format, resulting from the lossless transformation of the ENC. The phrase lossless transformation was added basically to ensure that when the conversion took place outside the Ecdis the data was not downgraded in accuracy or contents.

It took more than five years for the SENC method of distribution to be accepted. And another five before the definition changed in the PS.

Who says there is no bureaucracy in Electronic Charts?