OpenCPN Version 4.8.0 Released

[bcn]

Originally Posted by brucechun

The different is it displays nothing more than the original chart without any corrections, does not mattered it is good or bad.

Bruce,

do you have a reference screen shot how the information should be displayed?

If you have update chart sets you will need to read the file always in the right order - base chart and then the corrections/updates in the exact order.

Can you please make a screenshot of the relevant directory with the contents for the charts and its updates in question?
Something like this:



And as Dave already requested: the log file please as well.

Hubert

[brucechun]

Hi,

The screen capture of the directory holding the files is attached. As well, more detailed information about the corrections available to this latest ENC version 2017.1 from the government website was captured. The version 2017.1 is updated to eNTM 10_2017 which most of the corrections to charts were not started with .001. The C25C505W even started with correction .023.

When I look into the logfile, it appeared to me that OpenCPN looks at correction files starting from 001. It will suggest an error if the first correction is not 001.
Bruce

[bcn]

Bruce,

the log file would be helpful.

Here another example of a S-57 set.



I don't see in your directory the ENC_ROOT directory with the CATALOG.031 file.

To build the chart, the base edition plus all the updating sets are required in strict order - if not the chart can't be build correctly.

It is possible that a Hydrographic office issues single updates - but then you will need to install the base chart and the following updates before.

You might tell us a bit more about these charts from HK - how they are organized and distributed perhaps.

Hubert

[brucechun]

Dave,

The screen capture of 4.8 looks exactly the base chart. The dotted square near the green light under the bridge was a dredging area that has been completed and removed.

And the screen captures of 3.2.2 and 4.4 look are correct as the old dredging area removed and the new dredging area near the cardinal mark and lateral red marks have been added.

Bruce

[brucechun]

It does not change anything if the CATALOG.031 were there or not. I normally not include the file with the corrections as OpenCPN seems to require all the correction files put in the same directory as the ENC charts.

In Hong Kong, they re-compile ENC from every a few year to included all the corrections. Just like the 2017.1 was actually charts all the way from the very beginning of version 2 which is revised in 2005. Instead of renewing the chart completely to version 3 like the C23C301E and C23C302W that started their correction from 001 again. The rest of the charts remained version 2 but incorporated all previous corrections up to eNTM 10_2017. In other words, the older corrections already applied and need not to be there (that is what they said). The chart viewers should be able to tell the next correction is starting from something else other than 001.

I tried to manually change the extension to 001, 002 and so on to make them sequential. It seems to work with OpenCPN. However, it should not be. I am not sure if there is information about where is start with correction. It seems to me that correction is not necessarily started from 001 as what the hydro office doing here. And it should be a huge problem if it was wrong for them to do so as all the ships' ECDIS will fail just like OpenCPN. It is serious. I do not think the hydro office will kept unaware if it is a problem for not starting correction file from 001.

[bcn]

Bruce,

this is what the S-57 standard says about the base and update cells:


5.6.3 Data set files
The re-use of cell names is prohibited.
The data set files are named according to the specifications given below :
CCPXXXXX.EEE
| | | |----- EEE = update number
| | |-------------XXXXX = individual cell code
| |---------------P = navigational purpose
|-------------------CC = producer code

The main part forms an eight character identifier where :

• the first two characters identify the producer. This list is given in Annex A to Appendix A (IHO Object Catalogue).

• the third character indicates the navigational purpose (see clause 2.1).

• the fourth to eighth characters are used for the cell code. This code can be used in any way by the producer to provide the unique file name. If characters other than numbers are used only uppercase letters are allowed.

A valid base cell file must be uniquely identified world wide by its name,
and have the extension 000.

The names of previously cancelled base cell files must not be re-used for subsequent new base cell files.

The extension is used for updating (see clause 5.7).

Update cell files have the same name as the original base cell file,
with an extension number greater than or equal to 001.

They cover the same geographical area as the base cell file to which they apply.

[bcn]

Bruce,

some more information from the S-57 standard - regarding the update sets and its enumeration:


5.7 Updating
In order to ensure that updates are incorporated into the SENC in the correct sequence without any omission, the file extension and a number of subfields in the eData Set Identificationd [DSID] field are used in the following way :
file extension
edition number
update number

Every new data set, re-issue or new edition must have a 000 extension.

For update cell files the extension is the number of the update, ranging from 001 to 999.
These numbers must be used sequentially, without omission.
Number 001 is the first update after a new data set or a new edition, but not after a re- issue.
The update sequence is not interrupted by a re-issue. After a re-issue, subsequent updates may be incorporated into the SENC created from this re- issue or to the SENC created from the original data and kept continuously updated.

When a data set is initially created, the edition number 1 is assigned to it. The edition number is increased by 1 at each new edition. Edition number remains the same for a re-issue.

Update number 0 is assigned to a new data set. The first update cell file associated with this new data set must have update number 1.
The update number must be increased by one for each consecutive update, until a new edition is released. The new edition must have update number 0.

A re-issue of a data set must have the update number of the last update applied to the data set. In the case of an update cell file the file extension is the same as the update number.

[brucechun]

It appears to me that is exactly the case. They are re-issuing charts.

"For update cell files the extension is the number of the update, ranging from 001 to 999.
These numbers must be used sequentially, without omission.
Number 001 is the first update after a new data set or a new edition, but not after a re- issue.
The update sequence is not interrupted by a re-issue. After a re-issue, subsequent updates may be incorporated into the SENC created from this re- issue or to the SENC created from the original data and kept continuously updated."

... "the number of the update, ranging from 001 to 999... numbers must be used sequentially, without omission " ... is it not necessarily started with 001? Most of the charts here are not new data set after all. They are re-issues.

... "The update sequence is not interrupted by a re-issue" ... so the update files must be continued the last one before the re-issue that will not started with 001 again.

If the ENC files itself cannot tell if it is a new data set or a re-issue, should it be a way to tell the program which is which?

And I think they are not cancelling any chart. Therefore, they are using the same chart number.

[bdbcat]

Bruce/bcn....

I agree with Bruce. I think HK are "re-issuing" cells. So, the updates need not start with 001, but starts with "one number above" the last update already present in the re-issued .000 file.

Never seen an HO operate this way, but seems to be allowed by the spec.

Clearly, OpenCPN does not understand this, so flags as an error. Should be an easy fix, and I will study this using HK as the base case..

Bruce: We are not actively planning an update to O4.8 very soon, so it may be a month or so before this happens in production. Are you in critical need now?

Thanks
Dave

[bcn]

Dave/Bruce...

perhaps a case to discuss with the HK Hydrographic Office.

Even if the standard allows to publish re-issued cells with updates starting with denominations >1 this creates the situation that missing updates might not been detected:
Imagine updates 23, 24, 25 are present but the re-issued cell does only cover up to update 20. Nobody can detect the two missing previous updates 21 and 22.
Not good...

Bruce: are these cells directly issued in S-57 format or are you getting S-63 sets?
Who can license or access these charts?
We would be interested to make those accessible for OpenCPN on a general basis.

Hubert

[brucechun]

Dave: I have downgraded the software back to version 4.4. It is fine for me as I mainly use the viewer to monitor AIS movement around me. Actually, I like the thinner look of AIS targets in 4.4.

Hubert: Although I fully agreed with your view, I am not sure talking to them will work. As you said, they have follow the rules. There must be strong reasons for them and IHO to allow it. Actually, they use a system from aboard to maintain their data and issue ENC. The software did that all. They did renew charts just like the 301 and 302. For some reasons, they are not renew them all.

They are in pain S57 format. We can buy a license to use the data. During the licensed period, we are allowed to go into the HO website and obtain updates.

Provided the correction starting number of a "re-issued cell" is known, and the updates after that are sequential and uninterrupted, it is petty safe.

[bcn]

Bruce,

two points:

- you might just point the agency to this discussion. Perhaps they will comment, perhaps not.

- as you might know we are licensing chart material for Opencpn already.
More information at o-charts.org
Many Hydrographic Offices do allow for licensing schemes different form the strictly commercial usage (S-63).
It would be interesting to learn if HK is interested in such an use case.

Hubert

[brucechun]

Hubert,

I think they will be interested in licensing their charts. In the past few years, they have been busy in stopping unlicensed uses of their ENC data in varies program that display Hong Kong cells such as SeaIQ and Navonics.

You may email Michael Chau using the email address at the Hong Kong HO. Michael is the head of HKHO. (You may tell Michael that it is me suggesting you to contact him. I am sure that he will NOT give you any special discount because of this!!)

Bruce

[pendragon]

My apologies if this is the wrong thread, how to start a new one eludes me..
I use OpenCpn on my laptop without any problems , BUT on a Android tablet using the app is problematic.
1) How to add icon for color scheme eh night vision(navigation) The use of F6 or any keyboard shortcuts button is a problem
2) How or where(eg download) to install extensions like Celestial Nav.)
Many thanks for any help

[rgleason]

Originally Posted by pendragon

My apologies if this is the wrong thread, how to start a new one eludes me..
I use OpenCpn on my laptop without any problems , BUT on a Android tablet using the app is problematic.
1) How to add icon for color scheme eh night vision(navigation) The use of F6 or any keyboard shortcuts button is a problem
2) How or where(eg download) to install extensions like Celestial Nav.)
Many thanks for any help

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