Charts

[jonasaberg]

Marco, Dave:
I agree with you both:

1. I agree with Marco: Don't trust SK etc, at least put greater trust in the ref points. Maybe use ref points to check DY,DX values? In most cases the ref points are used to automatically calculate DX,DY in the first place, so this check would be for checking the application (or human) creating the header file.

2. Dave, as you I really think we should use the projection when it is stated in the BSB header. The equations seem to be in the Proj4 which is already used. (Correct me if I am wrong)
e.g.
PROJ.4 - Trac
I dont understand all the details, specially how to use the ref points if the projection is off. As I understand it, nowadays the projection is usually very good (near perfect) for new commercial charts since the charts are not scanned anymore. The errors are usually induced by the ECDIS.

Anyway, with mercator and transverse mercator equations a large number of charts would be well covered. Maybe we could ask the community which projections are used in the charts we have access to in all our countries?

3.
On top of using the correct projection equations the methods suggested by Dave/Marco seems god.

It really is, as I think Marco stated earlier, the commander of the ship that is responsible. With this comes the responsibility for good electronic charts. Either checking them or acquiring them from a trusted source. Some error checking by OpenCPN is always good, but in the end it seems logical that the projection in the "paper chart" that is the basis for the BSB chart should be stated in the kap file and used in the ECDIS software, OpenCPN in this case.

4.
Regarding the issue with the missing SK value in the 9312_gotaalv.kap chart, I have heard that the SK value is not mandatory in kaps since it can be calculated from the ref points. So as Dave and Marco suggest, it should be calculated.

5. I really like the idea someone suggested to put a grayed zone around the vessel indicating the accuracy of the system. We always have measurement errors. Always. I think most of us have read articles about this.
We have the inaccuracy of the chart (includes the inaccuracy based on the date when the chart is from. In may areas well over a hundred years ago with the accuracy in bearing, distance and depth used then). The inaccuracy of the printing system and digitizing/referencing, assuming scanned charts.
Finally the varying error in positioning using a GPS.

To put a grayed circle (that can be turned of) around the boat would be a nice remainder of this.

/Jonas

[GPS-Marco]

Hello.

I'm very close to release the first "official" New Zealand Chart Set for OpenCPN and Seaclear. I'm just finishing final checks. By doing that I've realized the following things:

1) as said by someone already, the sentence OST/1 should be required in the KAP header. Well I've found that when (and only when) it is in, the chart can be opened by NOAA chart reprojector.

2) someone said that maybe also CPH/0.0 should be in (not only when it is 180.0). I've not found any case where this is required, but just in case...

3) When a chart is in Transverse Mercator, the PP parameter shall contain the central meridian of projection.

I've prepared a new mc2bsbh (version 9) that add those new info in the KAP header. I'd like to know if charts generated with this new info can be opened by some other SW. I've succesfully tested on:

- OpenCPN
- SeaClear/MapCal
- NOAA chart reprojector
- PolarView

I'm attaching the smaller NZ chart I have and I ask you to try to check if this chart can be opened by some other SW you own or you use.

Let me know, so I can release the NZ portfolio with this new header.

Ciao, Marco

[sinbad7]

Marco..

Your NZ6823_1.kap map worked fine in all of these:

OpenCPN
SeaClear
OziExplorer
Fugawi MARINE ENC
MapCal

I tried adding just OST/1 somewhere in the header but I still could not use the charts anywhere else but OpenCPN and SeaClear. What am I missing?

Great job!!

Tore

[GDD]

Hi Marco;

In regards to other software:

I used your tool to download and convert/calibrate the NZ charts back when you post your first prelimanry complete set.

I go back and forth between MaxSea and OpenCpn when I'm cruising. (I love OPenCpn, but other members of my computer illiterate family are happier sticking to what they know, which is MaxSea, hence my comments in feature requests to match some of the keyboard shortcuts....anyways, i i digress)

The NZ charts don't work in MaxSea10 or an old verison of Nobeltec I have V4). In Maxsea I see chart outlines in the correct place with the correct label but there is no image shown. Nobeltec does worse, it gives nothing but error messages.

I suspect the probem is the image format, though I"m no expert. These charts are the only ones i've seen where the image file is .tiff. I tried changing the extention to .bsb but it made no difference. I love the charts and will use them in NewZealand in March. Thanks for all the hard work.
george

[jonasaberg]

If the files you are using for navigation are tif files you made something wrong. I the end you should have a bunch of .kap files. The kap file includes both the information about what the chart covers (the scale, Lat and Longs of the chart etc) and the image information which is not tif.

Read here on Marcos site describing how to do it:
MCE66 - Software
and how it works here
MapCal Utilities


Good luck

/Jonas

[GPS-Marco]

Originally Posted by sinbad7

Marco..

Your NZ6823_1.kap map worked fine in all of these:

OpenCPN
SeaClear
OziExplorer
Fugawi MARINE ENC
MapCal

I tried adding just OST/1 somewhere in the header but I still could not use the charts anywhere else but OpenCPN and SeaClear. What am I missing?

Great job!!

Tore

Thanks Tore. After adding OST/1, have you run bsbfix?

Anyway If everithing goes right we can release mc2bsbh beta 9 and you will be able to create the same header of this NZ map.

Ciao, Marco.

[GPS-Marco]

Originally Posted by GDD

The NZ charts don't work in MaxSea10 or an old verison of Nobeltec I have V4). In Maxsea I see chart outlines in the correct place with the correct label but there is no image shown. Nobeltec does worse, it gives nothing but error messages.

Hello George,

I've seen MaxSea very few times (was not on a my PC, don't remember the version) but I remember that to view new charts I had to close (on the file menu) the current ones. I guess there were CM93 selected when new charts were loaded, but only after having closed CM93 other maps become visible. But I cannot help you more than that (I don't have MaxSea). Even less help for Nobeltec that I've never seen. But please, post the error messages. Maybe we can understand the issue.

Anyway if you (or other people) manage to modify by hand the .kap header to make experiments, always remember to run bsbfix on the chart to fix the .kap index.

Ciao, Marco.

[cagney]

I don't have any possibility to test MaxSea and others either, but perhaps it has nothing to do with the kap file. It might just be that these programs expect a .bsb file for every .kap. This can easily be tested by creating a .bsb file for any .kap NZ chart. I think that all the info you need for this is already available. Just check any commercial/official BSB3 chart for the format, for example.

Thomas

[idpnd]

Not sure if these easterrn med charts have been posted here before

[Leo12305]

Originally Posted by idpnd

Not sure if these easterrn med charts have been posted here before

Yes see ' 469 from Sindbad
leo

[idpnd]

Danke Leo.. That's probably where I sourced the link..

[GDD]

Hi

I always figured that the .kap file was the position/projection data and the .bsb was the image, looks like I had that all wrong....

Anyways, I put the .kap files in a directory on their own and the issue was the same (OPenCpn was opened the files, maxsea and Nobeltec won't)

Beyond that, I don't really know what to do here. I found a NOAA BSB/Kap file combo and looked at both files in Word Pad to try and see what the relationship is, but I"m not any sort of programmer so that doesn't look like a route I might be able to look at with out a serious learning curve.

For what its worth I attached images of what I get when I try to open the charts in maxSea and Nobeltec.

thanks
george

[GPS-Marco]

George, have you tryed the map NZ6823_1.kap attached to the thread #499 It is built with a bit different header. Let me know.

Ciao, Marco.

[sinbad7]

Marco..

Had a look at your header in your small NZ chart but I'm affraid it's all Greek to me. Strange codes and links to websites etc.

Where can I download the latest version of mc2bsbh ?
I normally use 'Chartconverter' for my conversions having first prepared the .png and CHARTCAL.DIR files. The program also makes use of mc2bsbh.

The NONImapViewer is great for catching large areas in OpenStreetMap which creates a .map file for OziExplorer with all the calibration data of the map's corners,useful also to make a CHARTCAL.DIR file. The created map is in .tif
NONImapViewer will soon also be available for OpenSeaMap inputs.

All my created .kap charts will run on OpenCPN,SeaClear and OziExplorer but NOT presently on Fugawi MARINE ENC.

[GPS-Marco]

Originally Posted by sinbad7

Marco..

Had a look at your header in your small NZ chart but I'm affraid it's all Greek to me. Strange codes and links to websites etc.

Where can I download the latest version of mc2bsbh ?
I normally use 'Chartconverter' for my conversions having first prepared the .png and CHARTCAL.DIR files. The program also makes use of mc2bsbh.

The NONImapViewer is great for catching large areas in OpenStreetMap which creates a .map file for OziExplorer with all the calibration data of the map's corners,useful also to make a CHARTCAL.DIR file. The created map is in .tif
NONImapViewer will soon also be available for OpenSeaMap inputs.

All my created .kap charts will run on OpenCPN,SeaClear and OziExplorer but NOT presently on Fugawi MARINE ENC.

Tore, All the lines in kap header starting with ! are comments and should not make any difference. All that stuff is used by KapGen to generate the map automatically.

New mc2bsbh will be released soon (say this week end) since I've not received negative blocking reports.

I'll also try to release a new KapGen (using the new mc2bsbh) and the New Zealand portfolio.

Ciao, Marco.