OpenSeaMap - S57-Based

[sinbad7]

As an alternative/supplement to CM93, I think the (Open Source) OpenSeaMap could be a useful map system after some adjustment are made to the S57 coding,making it compatible with the S57 standard.

OpenSeaMap - The free nautical chart

I know very little about map making but it seems to me that this open source map system could be an excellent opportunity to construct a useful nautical version of the OpenStreetMap. I know we have people here with such capabilities and I would very much like to have some inputs from them as regards the feasability and interest in such a task.

The present maps totally lack soundings and navigation features,the latter being easily added either from within OpenSeaMap,or within OpenCPN.
Transparent overlays is also a method which could be used to add soundings and other nautical features.

The promoters of OpenSeaMap is launching the free map system at the major boat show in Duesseldorf in January based on several free navigation programs including OpenCPN. They have told me they have no facility presently for further development and would be grateful for any assistance.

I have converted a dozen or so charts in the .kap calibration,compatible with OpenCPN.

[sinbad7]

Here is a working example of Valencia harbour with traffic as of 20:00 UTC today.

Overlay of seafront to scale and some cosmetics.

[dacust]

OpenSeaMap

I'm afraid I don't see any practical use for screen prints of maps (especially with AIS traffic) converted for use in OpenCPN. It basically combines all the disadvantages of vector charts with the disadvantages of raster charts in the process, while loosing the advantages of vector charts.

The only use I can see for this is if the maps from OpenSeaMap can be downloaded and natively used in vector format in OpenCPN. As they exist now, they are still only of use for knowing what is on land. As information is added, they could well become a valuable navigation tool. So, I see great possibilities for OpenSeaMap being used in OpenCPN. Just not yet.

Layered Maps

I also am not excited about creating partially transparent layers in a raster chart that is then displayed.

For this, the transparency needs to be a function inside OpenCPN, so the user can choose the charts to be superimposed and choose their own transparency level.

-dan

[sinbad7]

Dan..

Whilst I do not entirely agree with you regarding the value of ´screen prints´of maps,my argument is that here we have an open source S57 based map system available to us for further development. Apart from the BSB charts of the USA,Australia and Brazil, we have no other legal map source.
Can anyone tell me this is not worth exploring?

The sample attached earlier is a perfectly calibrated .kap chart,proved by the apparently much disliked AIS targets displayed. I might add that I have myself for many years navigated perfectly safely on scanned and calibrated ´screen prints´ in the North Sea,Baltic and the German Bight with Fugawi navigation software.

The challenge is there,we need technicians fully conversant with the S57 standard to do a feasibility study of the OpenSeaMap system and it´s future possible compatibility with OpenCPN.

[idpnd]

This could be a data repository for sharing navigational data amongst cruisers. It still has way to go to be a free source of charting data..

I assume the data would have to be copied across manually from vector/raster charts?

[dacust]

Originally Posted by sinbad7

...,my argument is that here we have an open source S57 based map system available to us for further development...

Yes, I agree with you, as I said in the second paragraph if that post.

And I don't hate the AIS targets. But I don't see the value of creating a static chart with them on it so you can see where the targets were at the time the chart was made. It looks cool, though.

-dan

[sinbad7]

And I don't hate the AIS targets. But I don't see the value of creating a static chart with them on it so you can see where the targets were at the time the chart was made. It looks cool, though.

The reason for including the AIS targets was to show the authenticity of the calibrated map. Compare the geo loc of the ship in the query box with the geo loc of the cursor pointer shown in the status bar.

The OpenSeaMap is properly geo referenced,as can be seen in the lower right hand of their maps.

Enough said I recon,the gauntlet has been thrown....

[dacust]

Originally Posted by sinbad7

The reason for including the AIS targets was to show the authenticity of the calibrated map.....

Ah, OK. I missed that.

[oem]

The right solution is (I think) an interface to OSeaM so that mapareas can be converted and downloaded from OSeaM directly into OpenCPN. That interface should/could be part of the OSeaM-project. The same principle as for NOAA-chart-download. I had a small mail correspondence with Markus Bärlocher from the OSeaM-project. And I think he agreed, since S57(S100) is the future standard for nautical maps. The problem is to find people to program it (I'd like to, but I'm afraid my programming experience is too outdated ).

At present OSeaM seems to focus on an interface for Seaclear, - I tried to convince him that S57 (and OpenCPN) would be even better to focus on, but in any case if the maps fits seaclear then they can be converted to BSB and OpenCPN also.

It will help the OSeaM-project in creating trustworthy data that a usable interface is present. But there's a long, long way to go before usable maps can be downloaded.

I think that OSeaM-charts have an internal format that is a combination of OpenStreetMap-database for some parts and then S57 for the nautical additions (buoy's etc..). So some programming has to be done..It's not just S57 (which I don't know much about either, I guess it's not just XML, but some other technical stuff).

[sinbad7]

oem..

You are right of course,the OpenSeaMap chart system must be directly accessable by OpenCPN from own PC,similar to CM93 v.2 Another problem is the lack of soundings and sea markers/lights.

The .kap conversion/calibration of OpenSeaMap screen dumps is already in place using the mc2bsbh converter. A great help is that OpenSeaMap is geo referenced at the cursor for ease of identifying calibration points.

It is also possible to copy the soundings from other charts of the same scale to merge with the newmap.tif in preparation before the conversion. Yes,a fair bit of work,but it DOES function.

What is needed at this stage is a feasability evaluation from someone properly conversant with the S57 standard to let us know if the OpenSeaMap system is worth persuing and if someone is willing to take on the challenge.

[oem]

Yes, I agree.

But if the OpenStreetMap-project has been able to set up data capture through everybody's use of gps and the possibility to edit OSM-maps online, then I think there is a fair chance that the same could be possible for OpenSeaMap also. I don't see other possibilities (except similar ideas, and they would have the same obstacles).

The one and only huge big challenge is to make the data trustworthy and permanently updated. A challenge that has to compete with governmentally financed marine institutions and other marine organizations. And for sailing the quality of data is of much higher importance than for streets.

The only alternative is political decisions to make nautical chart information free to everybody (like NOAA). The information is there, - it's the cost of getting the information from the originating source that counts.

Well breaking copyright laws is also a possibility, but not very obvious

For my region the information can be bought/subscribed through Primar-Stavanger and a few others, and the information is produced through KMS, the danish institute for mapping-data and geographical data collection (don't know the english equvalent name). But the cost of buying/subscribing is based on ECDIS requirements for the marine industry, not for 'leisure' and 'hobby'-sailing. That is, - expensive...

So OpenSeaMap is an obvious possibility as a free, open source, cloud etc. -project...With an S57-interface to OpenCPN

[sinbad7]

The .kap conversion/calibration of OpenSeaMap screen dumps is already in place using the mc2bsbh converter. A great help is that OpenSeaMap is geo referenced at the cursor for ease of identifying calibration points.

It is also possible to copy the soundings from other charts of the same scale to merge with the newmap.tif in preparation before the conversion. Yes,a fair bit of work,but it DOES function.

Here is a rough example of a .kap conversion with a C-Map transparent overlay.

This is NOT the cm93 v2 which does not display any soundings at all for Palma port at this level. Is that a mistake in OpenCPN's algorithm?

[oem]

The problem with the c-map overlay is, - I guess, that the information is copyrighted and therefore not downloadable by all?

In the 'Vector Charts'-folder there is a mark for 'ShowSoundings', - did you mark that correctly?

[sinbad7]

Hi all,and a Happy new Year!!

I happened to be browsing the Norwegian Coast Guard website and look what I found:

They have adapted the OpenSeaMap system and have created a FREE,fully ECDIS compatible nautical sea chart system. It is available on-line for all with internet connection,and many boaters in Norway makes use of the 7/24 based 3G and 4G mobile phone system to get their chart information. Have a look at the detail of the attached chart.

Access the Norwegian Coast Guard pages here:

The big question is,if they can do it,why can't we?

[idpnd]

Link? Is it permitted to download these charts? Theyre probably the same data as the c-map sets..