Charts

[SailKraken]

The 3 S57 charts from COE lock up the program. All others work fine. Fugawi Viewer shows the charts OK. It it the program? New user. Not sure if this is how to ask question.

[BluegillBoy]

Marco - I can email one. 200kb or so in PNG format. Or maybe I could find a way to upload it at work.

Cagney - even if I craft the header, how do I calibrate the chart without MapCalII? these are coming from PDF scans. if there's another way, I'm all about it.

[Algarve]

Hello again,
Maybe this is not the most appropriate forum, but can you help me?
I have CmapEcs4 on Vista computer, and can not open the Charts CM93, the program opens and the gps works too well, but Charts not.
What will happen?

[cagney]

Originally Posted by BluegillBoy

Cagney - even if I craft the header, how do I calibrate the chart without MapCalII? these are coming from PDF scans. if there's another way, I'm all about it.

Yes there is another way. That is what this thread is all about. Please read from the beginning. Mapcal came into the picture when the basics was sorted out, and some people was looking for an alternative, to make calibration easier. Dacust started a project (separate thread) to automatically translate the file that Mapcal creates for a chart, to a template file (or header) suitable for tif2bsb. This made Mapcal a viable tool for creating kap-bsb charts for use with OpenCPN, but it has never been a necessary tool.

Thomas

[cagney]

Originally Posted by SailKraken

The 3 S57 charts from COE lock up the program. All others work fine. Fugawi Viewer shows the charts OK. It it the program? New user. Not sure if this is how to ask question.

To look at your problem a lot more info is needed.
Please publish your log-file. Instructions towards the bottom of this page:Installing OpenCPN | Official OpenCPN Homepage
Please give the chart number for the charts you have problems with. I, and many others don't normally have US charts loaded.
Which operating system/version are you using?

If you only have problems with three ENC S57 charts, try to download them again, before proceeding.

Thomas

[cagney]

Originally Posted by Algarve

Hello again,
Maybe this is not the most appropriate forum, but can you help me?
I have CmapEcs4 on Vista computer, and can not open the Charts CM93, the program opens and the gps works too well, but Charts not.
What will happen?

The chart formats that works with OpenCPN are listed here:
Chart Formats | Official OpenCPN Homepage

Notice that CM93 version 3 and later do not work with OpenCpn.
Exactly what is "CmapEcs4"? A quick search on the net gives no useful info.

Thomas

[Totobeloeil]

Originally Posted by cagney

Exactly what is "CmapEcs4"? A quick search on the net gives no useful info.Thomas

It is the program distributed with some old CM93-2 charts.

Originally Posted by Algarve

I have CmapEcs4 on Vista computer, and can not open the Charts CM93, the program opens and the gps works too well, but Charts not.
What will happen?

It does not work for me neither. I used 'C-Map World Viewer' instead, but it was in another life, before I knew OpenCPN.

Jean-Pascal

[cagney]

So if CmapEcs4 "is the program distributed with some old CM93-2 charts", and this doesn't work on Vista, it has nothing to do with OpenCPN? Or have I misunderstood both of you?

Thomas

[Totobeloeil]

Originally Posted by cagney

So if CmapEcs4 "is the program distributed with some old CM93-2 charts", and this doesn't work on Vista, it has nothing to do with OpenCPN?

That's I believe. Jean-Pascal

[GPS-Marco]

Originally Posted by BluegillBoy

yup. these are the PDFs posted by USACE. i've got the enc vector charts, but the PDFs have much more information on them. i rotated each PDF to be north up, calibrated them with MapCalII, and they work. but because they're rotated, some are hard to read.

but if i don't rotate them to north up, MapCalII won't calibrate them.

catch 22.

Ciao,
well I tried to calibrate the map and I got those results:
1) the map is 91 degrees skewed. It means that it has north downwards.
2) you will need 4 ref points in MapCal to calibrate the map. MapCal will still warning of swapped N/S and E/W, but it works and it will save the CHARTCAL.DIR file
3) if you use standard mc2bsbh on CHARTCAL.DIR and then tif2bsb you will have a map that shoud be fine. Anyway it will not work in OpenCPN. This is a problem of OCPN in working with skewed charts.
4) if after using mc2bsbh you open the .hdr file with a text editor and change SK=UNKNOWN with SK=91, and then use tif2bsb to generate a new map, OCPN still does not work fine for the reason it is unable to calculate a good georeferencing polynomial set.
5) if instead of the standard mc2bsbh you use the mc2bsbh-poly and allows the included georef algorithm to write the polynomials inside the kap header (use -p switch), and then use tif2bsb, well you will succeed. The generated map will work in OCPN.

mc2bsbh-poly can be found here #531

I attach here some intermediate files: the CHARTCAL.DIR and the Chart79.hdr generated with mc2bsbh-poly with the polynomials inside.

Ciao, Marco.

[Totobeloeil]

Originally Posted by GPS-Marco

MapCal will still warning of swapped N/S and E/W, but it works and it will save the CHARTCAL.DIR file
[...] if instead of the standard mc2bsbh you use the mc2bsbh-poly and allows the included georef algorithm to write the polynomials inside the kap header (use -p switch), and then use tif2bsb, well you will succeed. The generated map will work in OCPN.

Really interesting job ... Thanks, Marco !

Does it mean we could use conical projected charts (Lambert or NAD83 charts, for example) into OpenCPN without reprojecting them before calibratation ?

Jean-Pascal

[GPS-Marco]

Originally Posted by Totobeloeil

Really interesting job ... Thanks, Marco !

Does it mean we could use conical projected charts (Lambert or NAD83 charts, for example) into OpenCPN without reprojecting them before calibratation ?

Jean-Pascal

The answer is...

First mc2bsbh-poly only supports Merc and Tmerc. Second, OCPN only projects on screen in mercator, so you will alway have a distorsion for other projections even if the georeferentiation is correct.

mc2bsbh-poly has 2 objectives:
1) make an algoritm to calculate good polinomials for chart georeferentiation in kap v3 format. But I've described that even if this is better then OCPN internal one, the third order poly method does not work for small scale charts (1:3000000 and smaller). Not a problem of the algo anyway.
2) suggest a new way to georeference charts inside OCPN (i.e. first use projection and then use polynomials). This method will have an almost zero error in all cases (skewed, small scale, badly scanned, etc.) even if only mercator chart will be completely undistorted on screen.

Anyway I've seen that when OCPN fails in georeferencing charts (skewed charts, non mercator charts, etc.), in these cases mc2bebh-poly reduces considerably the error. Better than nothing... Give it a try.

Ciao, Marco.

[BluegillBoy]

Thanks, Marco. I'm playing with them right now. And as always, I'm full of questions. Obviously I'm new to this whole chart game.

I don't see the MD5SUM in the CHARTCAL.DIR. How did you run tif2bsb without that?

I've been using KapGenAll (going to do all 142 charts of the Illinois Waterway) to process batches. Can that be altered to batch run mc2bsbh-poly?

I've run the charts I calibrated with OpenCPN of course - all it takes are the .KAP files. To use them with SeaClear I have to put the CHARTCAL.DIR in the folder with the .KAPs. I tried to use them with the free version of MemoryMap Navigator, and it wouldn't accept them, maybe because they don't have an actual .BSB file with them? Here's where my little bit of knowledge runs out.

Anyway, thanks!

PS - check out the avatar - she's My Bluegill Heaven.

[GPS-Marco]

Originally Posted by BluegillBoy

I don't see the MD5SUM in the CHARTCAL.DIR. How did you run tif2bsb without that?

I've been using KapGenAll (going to do all 142 charts of the Illinois Waterway) to process batches. Can that be altered to batch run mc2bsbh-poly?

I've run the charts I calibrated with OpenCPN of course - all it takes are the .KAP files. To use them with SeaClear I have to put the CHARTCAL.DIR in the folder with the .KAPs. I tried to use them with the free version of MemoryMap Navigator, and it wouldn't accept them, maybe because they don't have an actual .BSB file with them? Here's where my little bit of knowledge runs out.

Anyway, thanks!

PS - check out the avatar - she's My Bluegill Heaven.

Ciao.

First answer is: I did not use KapGen. I just used mc2bsbh and then tif2bsb in a shell. I was only quicly testing the georeferentiation...

Second answer is: yes! change this line in the KapGen.cmd Batch:

bin\mc2bsbh -s %MAP% Calibration\CHARTCAL.DIR

in

bin\mc2bsbh-poly -p -s %MAP% Calibration\CHARTCAL.DIR

and of course put the mc2bsbh-poly.exe in the bin/ folder.

If the charts you are georeferentiating are free, please share your georef work with the community...

Third answer about SeaClear: to allow seaclear to use the KAP maps, please open MapCal, add the directory where the KAP charts are to the chart directory list (Tools>Set Directories) and then rebuild the chart data-base (Tools>AutoloadList>Recreate)

I can't help you for MemoryMap Navigator. Sorry, never used.

Ciao, Marco.

[BluegillBoy]

1) The poly is doing the trick. works great.

2) I'll absolutely share the finished charts. I've noticed a number of requests for the Illinois Waterway on various forums.

3) Next, you say "Second answer is: yes! change this line in the KapGen.cmd Batch:

bin\mc2bsbh -s %MAP% Calibration\CHARTCAL.DIR

in

bin\mc2bsbh-poly -p -s %MAP% Calibration\CHARTCAL.DIR"

but what I'm seeing in the file is:
bin\mc2bsbh -l %MAP% Calibration\CHARTCAL.DIR
(an "-l" rather than an "-s")
am I in the wrong place or has that command changed?

4) is there anyway to get an actual .bsb file? that seems to be the key to some other nav programs.