Open Chart Standard

[GPS-Marco]

QUOTE:
Originally Posted by HamishB
It really doesn't help that the technical committee which decided this is chaired by CMap (a division of Boeing), which has a vested interest in keeping the barrier to entry high. And that working ships will be required to use ENC in the near future (and so forced sales of the closed and expensive software with dongles and activations which can not be repaired at sea and so a system that fails dangerously...

QUOTE:
Originally Posted by idpnd
I call that corruption, just to keep things nice and plain

---

It's very interesting how the same things change name and modality depending on the country you live in. In Italy we call it Mafia, in US they call it Lobbying.

Ciao, Marco.

[brak]

I may not know much but I do know something about our own application. Polar View (Polar Navy) supports S63 charts, and last time I checked, we don't have any dongles. Feel free to download and see for yourself - it's free. Perhaps I am not so wrong after all, who knows

Also, just to get the terminology right - US NOAA charts are in S57 format, as they do not use S63 encoding (which is essentially an envelope for S57 chart). They are not the *only* free S57 charts, however - there are at least some areas out there covered by free S57 charts (though unfortunately, not nearly enough).

Originally Posted by idpnd

I'm afraid you are wrong, all post-CM93/2 products are dongled up to the 9s.. The only free vector charts in S63 come from the US govt

[HamishB]

Hi,

does any know of any NOAA produced RNCs which use the TRANSVERSE MERCATOR or LAMBERT CONFORMAL CONIC map projections? (these will not work with OpenCPN [yet ]).

If NOAA, I'd like to know the chart number. If not NOAA, by any other authority? I'd like to know what the KNP/ and KNQ/ lines (~4 of them) in the .KAP header look like.


thanks,
Hamish

[brak]

I have never seen one. That said, you can easily make your own using this tool:
Nautical Chart Reprojector - NOAA Digital Coast

Originally Posted by HamishB

Hi,

does any know of any NOAA produced RNCs which use the TRANSVERSE MERCATOR or LAMBERT CONFORMAL CONIC map projections? (these will not work with OpenCPN [yet ]).

If NOAA, I'd like to know the chart number. If not NOAA, by any other authority? I'd like to know what the KNP/ and KNQ/ lines (~4 of them) in the .KAP header look like.


thanks,
Hamish

[jonasaberg]

There is a free demo chart (a part of a full chart, but profesionally georeffed) here:

http://www.hydrographica.se/images/BSB-demo.zip

It contains the headers you ask for

/Jonas

[brak]

Cool, although since this chart covers such a tiny area (less than 1nm across) it really works fine in any viewer without reprojection. I wish they'd provide something covering at least a couple of degrees.

Originally Posted by jonasaberg

There is a free demo chart (a part of a full chart, but profesionally georeffed) here:

http://www.hydrographica.se/images/BSB-demo.zip

It contains the headers you ask for

/Jonas

[HamishB]

Originally Posted by brak

I am sure something will supersede S-57 but 5 years sounds like way too short of a timeframe.

That timeframe is from the local policy documents I have read. If it is still vaporware by that point I guess they'll miss their target.

Originally Posted by brak

I don't think any sort of dongles are required currently for S63 encoding (we certainly do not) and, in general, the era of "dongles" in software is long over - so I wouldn't be too worried about it.

umm, no. we currently have at least 3 dongled softwares running on our main ship. One for the main ENC chart plotter, one for the Trimble hydrographic survey software, and one for the sonar mapping software. They are alive and well and have made the transition from parallel port to USB stick (and from ship to office so we can work with the data once back home..)

I'm glad to hear that your SI program doesn't rely on one, as they are just one more thing to break, fail, & get lost.



As for "corruption" I won't use that word without direct knowledge. All I know is what I've read, and there seems to be some rather glaring conflicts of interest going on and gov't representatives who have been convinced (make your own assumptions by whom) that encryption is the only answer to make the maps tamper-proof. (pirates sneaking only the bridge and deleting a vectorized rock or some such scenario [surely it would be easier to do something to the engine, but whatever])

There is a valid concern if supertankers start to use half-baked buggy ENC plotters as their main navigational aid. (they probably are already, but it's a matter of perception)


Of course MD5sums and signed packages have been out there in wide use for more than a decade(+?), being used to verify that things have not been tampered with, but that might have been conveniently forgotten.

I'll give the gov't reps to the IHO the benefit of the doubt; I just wildly speculate that they've been fed selective advice by the market leaders with whom they consult with for advice, under the guise of national security.

If I may ask (feel free not to answer ), are there NDAs involved with decoding S63? secret keys? .. as you say, it depends on the encryption method used.

Originally Posted by brak

The above is my personal opinion, so it ain't worth much

an informed option is worth rather a lot.


also often wrong,
Hamish

[brak]

Originally Posted by HamishB

umm, no. we currently have at least 3 dongled softwares running on our main ship. One for the main ENC chart plotter, one for the Trimble hydrographic survey software, and one for the sonar mapping software. They are alive and well and have made the transition from parallel port to USB stick (and from ship to office so we can work with the data once back home..)

Yep. Some people never learn. That said, "dongle" is entirely a choice of the company making a product, though of course if you ask them - they will claim otherwise

There is a valid concern if supertankers start to use half-baked buggy ENC plotters as their main navigational aid. (they probably are already, but it's a matter of perception)

I am hanging on the forum of commercial sailors occasionally (came there when they started asking questions about using our GRIB viewer and download service). From what I read, you'd be surprised what kind of weird stuff they use on those ships and how often they have to string together a bunch of varied software from whatever is "handy" I am sure the "official" ECDIS system is installed on a bridge and running to satisfy any possible inspection, but that's not always what they do, evidently.

If I may ask (feel free not to answer ), are there NDAs involved with decoding S63? secret keys? .. as you say, it depends on the encryption method used.

There are no NDAs involved and the entire S-63 scheme is publicly available on IHO web site (though documentation, in my opinion, is rather poor and fuzzy on a number of crucial points, and they no longer provide reference code).

However, two important aspects:
1) they make you sign a document that prohibits you from building a product that can decrypt S63 charts and save them in S57 format (though you can save them in SENC - essentially a proprietary non-redistributable format of your choice). It also prohibits you from explaining to others how that can be done (though really the explanation is in the standard )

2) the security depends on keys they issue, and you sign a document saying you will not divulge those keys and will keep them hidden.

All that is on their site too, so in principle the scheme itself is open. However access to the scheme based on these rules will make it very difficult (impossible) for a GPL-licensed product to do so. With a BSD or otherwise permissivly-open source licensed product it may be possible to hide all of the S63-related stuff in a binary blob, and be compliant. The question remains as to who is the entity that would be issued the keys and remain responsible for maintaining the standard etc. I suspect they will want a private entity that has "something to lose" and can be held accountable in case it violates the rules.

[HamishB]

Originally Posted by jonasaberg

There is a free demo chart (a part of a full chart, but profesionally georeffed) here:
http://www.hydrographica.se/images/BSB-demo.zip
It contains the headers you ask for

thanks. That shows PP and P1 look like +lon_0; PC="TC"; P2=(scale factor??); P3=+lat_0(??).

Originally Posted by brak

you can easily make your own using this tool:
Nautical Chart Reprojector - NOAA Digital Coast

hmmm,the NOAA reprojection tool does not change the KNP/ and KNQ/ lines but it adds a ARC/ line in the header comments. The Pn= numbers seem a bit different. Reprojecting from merc into tmerc I get:

• P3= in the ARC/ line is scale factor
• P4= 0 (??)
• P5= central meridian
• P6= origin of latitude
• P7= +x_0
• P8= +y_0

So in KNQ/ P3 is +lat_0 but in ARC/ it is the scale factor. So Pn= changes meaning. bah.

I don't care about LCC as much but I'd like to see reading tmerc supported.


Hamish

[brak]

Originally Posted by HamishB

I don't care about LCC as much but I'd like to see reading tmerc supported.


Hamish

Any "quilting" viewer has to essentially pick one format (and Mercator is it, if you are a sailor). My own solution to something like that (if I were planning to support UTM, though there are no plans to do so right now) would be a tool, like NOAA's reporojection tool - though perhaps built into the program, may be even transparently to users. It would once and for all reproject the chart into a format that can be then used without constant mathematical trickery

[oem]

Originally Posted by HamishB

For QGIS you have to enable the Plugin.
Plugins -> Manage plugins -> tick Georeferencer. Then it's on the plugin menu.
Hamish

Thanks, I found it, must have been a bit blind, I'm playing with it now..

Originally Posted by HamishB

No, S-57's days are numbered. S-100 is the future and as I understand it the IHO has decreed that S-100/101 will be universally encrypted.
regards,
Hamish

The problem at the moment is lack of a standard for marine charts. And many formats. Just like any other war between standards like VHS og BETAMAX video tapes

I have read the very interesting discussion since yesterday. My opinion is still that S57 (S63) will and must be standard quite a number of years ahead. After that, naturally some S100/101 standard. As long as there is a standard, it's better than now.

And btw. polarview is the first (very nice) product I see with S63-support. I tried it and it worked fine. I hope S63 will be possible for OpenCPN too, but I know nothing about it.

As an alternative to official S63-charts, I also think, - as discussed in many other threads, that the OpenSeaMap-project is the most promising project for making an alternative to the officially produced s57-charts. But it has to be upgraded with a standard S57-interface, so that all S57-compatible navigation-programs can access them. Like OpenCPN and others. BSB-format should be there only as backward compatibility.

[oem]

I don't know whether www.openecdis.org has been mentioned before.
Quote: 'distribute ECDIS-related freeware/shareware software and S-57 datasets'

Sounds good, but unfortunately it seems that the link is more or less inactive. Any other information about the link?

[idpnd]

Hello Marco, I've just been to your page, (that is you isn't it?) to source the NZ charts for testing purposes, thanks very much for your huge work on this.

I've noticed that the NZ chart office actually seems to permit republication, but it wants attribution:

Where chart data is downloaded, reproduced, derived or copied from LINZ material, the following acknowledgement note must be shown on the product and associated media: "Sourced from Land Information New Zealand data. Crown Copyright Reserved."

Which is every so generous of them. Without wanting to be a bore, perhaps you want to put the disclaimer up on your site, and I guess we could even host the BSBed charts at opencpn.org with your permission?

[GPS-Marco]

Originally Posted by idpnd

Hello Marco, I've just been to your page, (that is you isn't it?) to source the NZ charts for testing purposes, thanks very much for your huge work on this.

I've noticed that the NZ chart office actually seems to permit republication, but it wants attribution:



Which is every so generous of them. Without wanting to be a bore, perhaps you want to put the disclaimer up on your site, and I guess we could even host the BSBed charts at opencpn.org with your permission?

Hello there. I was away for last week so I didn't answer before.

I put LINZ attribution everywere: when you use KapGen for any NZ chart, it prints it out, the KAP header of each chart includes it and if you download the full chart set (.7z), the readme begins with the LINZ credit. Do you think this should be also in the mce66 site? I'll put in the site too.

Of course you can redistribute the package (if you want to repack the 7z file, include the readme.txt, history.txt and use a file name with V22 inside for version tracking). Specify that those charts are not for navigation and that are free for personal (non-commercial) use only. And please, I'd appreciate a link to my web page.

And the last suggestion: those are charts made to work in OCPN and SeaClear. Since BSB is a closed spec, we cannot say they are "BSB" charts since we do not know if they are fully BSB compliant. Use at your on risk...

Ciao, Marco.

[idpnd]

Hello Marco,

thanks for your response. I have actually spotted the licensing info in the chart package now, that should probably suffice..

Thanks for your attention